CHAPTER 7 FIRE AND SMOKE PROTECTION FEATURES
User note:
About this chapter: Chapter 7 provides detailed requirements for fire-resistance-rated construction, including structural members, walls, partitions and horizontal assemblies. Other portions of the code describe where certain fire-resistance-rated elements are required. This chapter specifies how these elements are constructed, how openings in walls and partitions are protected and how penetrations of such elements are protected.
SECTION 701
GENERAL
701.1 Scope.
SECTION 702
MULTIPLE-USE FIRE ASSEMBLIES
702.1 Multiple-use fire assemblies.
SECTION 703
FIRE-RESISTANCE RATINGS AND FIRE TESTS
703.1 Scope.
703.2 Fire resistance.
703.2.1 Tested assemblies.
703.2.1.1 Nonsymmetrical wall construction.
703.2.1.2 Combustible components.
703.2.1.3 Restrained classification.
703.2.1.4 Supplemental features.
703.2.1.5 Exterior bearing walls.
703.2.2 Analytical methods.
The fire resistance of building elements, components or assemblies established by an analytical method shall be by any of the methods listed in this section, based on the fire exposure and acceptance criteria specified in ASTM E119 or UL 263.
1.Fire-resistance designs documented in approved sources.
2.Prescriptive designs of fire-resistance-rated building elements, components or assemblies as prescribed in Section 721.
4.Engineering analysis based on a comparison of building element, component or assemblies designs having fire-resistance ratings as determined by the test procedures set forth in ASTM E119 or UL 263.
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5.Fire-resistance designs certified by an approved agency.
703.3 Noncombustibility tests.
703.3.1 Noncombustible materials.
Materials required to be noncombustible shall be tested in accordance with ASTM E136. Alternately, materials required to be noncombustible shall be tested in accordance with ASTM E2652 using the acceptance criteria prescribed by ASTM E136.
Exception: Materials having a structural base of noncombustible material as determined in accordance with ASTM E136, or with ASTM E2652 using the acceptance criteria prescribed by ASTM E136, with a surfacing of not more than 0.125 inch (3.18 mm) in thickness having a flame spread index not greater than 50 when tested in accordance with ASTM E84 or UL 723 shall be acceptable as noncombustible.
703.4 Fire-resistance-rated glazing.
703.5 Marking and identification.
Where there is an accessible concealed floor, floor-ceiling or attic space, fire walls, fire barriers, fire partitions, smoke barriers and smoke partitions or any other wall required to have protected openings or penetrations shall be effectively and permanently identified with signs or stenciling in the concealed space. Such identification shall:
1.Be located within 15 feet (4572 mm) of the end of each wall and at intervals not exceeding 30 feet (9144 mm) measured horizontally along the wall or partition.
2.Include lettering not less than 3 inches (76 mm) in height with a minimum 3/8-inch (9.5 mm) stroke in a contrasting color incorporating the suggested wording, “FIRE AND/OR SMOKE BARRIER—PROTECT ALL OPENINGS,” or other wording.
703.6 Determination of noncombustible protection time contribution.
1.Test Assembly 1 shall be without protection.
2.Test Assembly 2 shall include the representative noncombustible protection. The protection shall be fully defined in terms of configuration details, attachment details, joint sealing details, accessories and all other relevant details.
703.7 Sealing of adjacent mass timber elements.
1.At abutting edges and intersections of mass timberbuilding elements required to be fire-resistance rated.
2.At abutting intersections of mass timberbuilding elements and building elements of other materials where both are required to be fire-resistance rated.
Exception: Sealants or adhesives need not be provided where they are not a required component of a tested fire-resistance-rated assembly.
SECTION 704
FIRE-RESISTANCE RATING OF STRUCTURAL MEMBERS
704.1 Requirements.
The fire-resistance ratings of structural members and assemblies shall comply with this section and the requirements for the type of construction as specified in Table 601. The fire-resistance ratings shall be not less than the ratings required for the fire-resistance-rated assemblies supported by the structural members.
704.2 Column protection.
Where columns are required to have protection to achieve a fire-resistance rating, the entire column shall be provided individual encasement protection by protecting it on all sides for the full column height, including connections to other structural members, with materials having the required fire-resistance rating. Where the column extends through a ceiling, the encasement protection shall be continuous from the top of the foundation or floor/ceiling assembly below through the ceiling space to the top of the column.
704.3 Protection of the primary structural frame other than columns.
Members of the primary structural frame other than columns that are required to have protection to achieve a fire-resistance rating and support more than two floors or one floor and roof, or support a load-bearing wallor a nonload-bearing wall more than two stories high, shall be provided individual encasement protection by protecting them on all sides for the full length, including connections to other structural members, with materials having the required fire-resistance rating.
704.4 Protection of secondary structural members.
704.4.1 Light-frame construction.
704.5 Truss protection.
704.6 Attachments to structural members.
704.6.1 Secondary attachments to structural members.
704.7 Reinforcing.
704.8 Embedments and enclosures.
704.9 Impact protection.
Where the fire protective covering of a structural member is subject to impact damage from moving vehicles, the handling of merchandise or other activity, the fire protective covering shall be protected by corner guards or by a substantial jacket of metal or other noncombustible material to a height adequate to provide full protection, but not less than 5 feet (1524 mm) from the finished floor.
Exception: Corner protection is not required on concrete columns in parking garages.
704.10 Exterior structural members.
Load-bearing structural members located within the exterior walls or on the outside of a building or structure shall be provided with the highest fire-resistance rating as determined in accordance with the following:
704.11 Bottom flange protection.
704.12 Seismic isolation systems.
Fire-resistance ratings for the isolation system shall meet the fire-resistance rating required for the columns, walls or other structural elements in which the isolation system is installed in accordance with Table 601. Isolation systems required to have a fire-resistance rating shall be protected with approved materials or construction assemblies designed to provide the same degree of fire resistance as the structural element in which the system is installed when tested in accordance with ASTM E119 or UL 263 (see Section 703.2).
Such isolation system protection applied to isolator units shall be capable of retarding the transfer of heat to the isolator unit in such a manner that the required gravity load-carrying capacity of the isolator unit will not be impaired after exposure to the standard time-temperature curve fire test prescribed in ASTM E119 or UL 263 for a duration not less than that required for the fire-resistance rating of the structure element in which the system is installed.
Such isolation system protection applied to isolator units shall be suitably designed and securely installed so as not to dislodge, loosen, sustain damage or otherwise impair its ability to accommodate the seismic movements for which the isolator unit is designed and to maintain its integrity for the purpose of providing the required fire-resistance protection.
704.13 Sprayed fire-resistant materials (SFRM).
704.13.1 Fire-resistance rating.
704.13.2 Manufacturer’s installation instructions.
704.13.3 Substrate condition.
704.13.3.1 Surface conditions.
704.13.3.2 Primers, paints and encapsulants.
Where the SFRM is to be applied over primers, paints or encapsulants other than those specified in the listing, the material shall be field tested in accordance with ASTM E736. Where testing of the SFRM with primers, paints or encapsulants demonstrates that required adhesion is maintained, SFRM shall be permitted to be applied to primed, painted or encapsulated wide flange steel shapes in accordance with the following conditions:
1.The beam flange width does not exceed 12 inches (305 mm); or
2.The column flange width does not exceed 16 inches (400 mm); or
3.The beam or column web depth does not exceed 16 inches (400 mm).
4.The average and minimum bond strength values shall be determined based on not fewer than five bond tests conducted in accordance with ASTM E736. Bond tests conducted in accordance with ASTM E736 shall indicate an average bond strength of not less than 80 percent and an individual bond strength of not less than 50 percent, when compared to the bond strength of the SFRM as applied to clean, uncoated 1/8-inch-thick (3.2 mm) steel plate.
704.13.4 Temperature.
704.13.5 Finished condition.
SECTION 705
EXTERIOR WALLS
705.1 General.
705.2 Projections.
Cornices, eave overhangs, exterior balconies and similar projections extending beyond the exterior wall shall conform to the requirements of this section and Section 1405. Exterior egress balconies and exterior exit stairways and ramps shall comply with Sections 1021 and 1027, respectively. Projections shall not extend any closer to the line used to determine the fire separation distance than shown in Table 705.2.
TABLE 705.2
MINIMUM DISTANCE OF PROJECTION
| FIRE SEPARATION DISTANCE(FSD) (feet) | MINIMUM DISTANCE FROM LINE USED TO DETERMINE FSD |
| 0 to less than 2 | Projections not permitted |
| 2 to less than 3 | 24 inches |
| 3 to less than 5 | Two-thirds of FSD |
| 5 or greater | 40 inches |
For SI: 1 foot = 304.8 mm; 1 inch = 25.4 mm.
705.2.2 Type III, IV or V construction.
705.2.3 Projection protection.
Projections extending to within 5 feet (1524 mm) of the line used to determine the fire separation distance shall be one of the following:
Exception: Type VB construction shall be allowed for combustible projections in Group R-3 and U occupancies with a fire separation distance greater than or equal to 5 feet (1524 mm).
705.2.3.1 Balconies and similar projections.
Balconies and similar projections of combustible construction other thanfire-retardant-treated wood shall be fire-resistance rated where required by Table 601 for floor construction or shall be of heavy timber construction in accordance with Section 2304.11. The aggregate length of the projections shall not exceed 50 percent of the building’s perimeter on each floor.
Exceptions:
1.On buildings of Types I and II construction, three stories or less above grade plane, fire-retardant-treated wood shall be permitted for balconies, porches, decks and exteriorstairways not used as required exits.
2.Untreated wood and plastic composites that comply with ASTM D7032 and Section 2612 are permitted for pickets, rails and similar guard components that are limited to 42 inches (1067 mm) in height.
3.Balconies and similar projections on buildings of Types III, IV and V construction shall be permitted to be of Type V construction and shall not be required to have a fire-resistance rating where sprinkler protection is extended to these areas.
4.Where sprinkler protection is extended to the balcony areas, the aggregate length of the balcony on each floor shall not be limited.
705.2.4 Bay and oriel windows.
Bay and oriel windows constructed of combustible materials shall conform to the type of construction required for the building to which they are attached.
Exception:Fire-retardant-treated wood shall be permitted on buildings three stories or less above grade planeof Type I, II, III or IV construction.
705.3 Buildings on the same lot.
For the purposes of determining the required wall and opening protection, projections and roof-covering requirements, buildings on the same lot shall be assumed to have an imaginary line between them.
Where a new building is to be erected on the same lot as an existing building, the location of the assumed imaginary line with relation to the existing building shall be such that the exterior wall and opening protection of the existing building meet the criteria as set forth in Sections 705.5 and 705.8.
Exceptions:
1.Two or more buildings on the same lot shall be either regulated as separate buildings or shall be considered as portions of one building if the aggregate area of such buildings is within the limits specified in Chapter 5 for a single building. Where the buildings contain different occupancy groups or are of different types of construction, the area shall be that allowed for the most restrictive occupancy or construction.
2.Where an S-2 parking garage of Construction Type I or IIA is erected on the same lot as a Group R-2 building, and there is no fire separation distance between these buildings, then the adjoining exterior walls between the buildings are permitted to have occupant use openings in accordance with Section 706.8. However, opening protectives in such openings shall only be required in the exterior wallof the S-2 parking garage, not in the exterior wall openings in the R-2 building, and these opening protectives in the exterior wall of the S-2 parking garage shall be not less than 11/2-hour fire protection rating.
705.4 Materials.
705.5 Fire-resistance ratings.
TABLE 705.5
FIRE-RESISTANCE RATING REQUIREMENTS FOR EXTERIOR WALLS BASED ON FIRE SEPARATION DISTANCEa, d, g
| FIRE SEPARATION DISTANCE = X (feet) | TYPE OF CONSTRUCTION | OCCUPANCY GROUP He | OCCUPANCY GROUP F-1, M, S-1f | OCCUPANCY GROUP A, B, E, F-2, I, Ri, S-2, Uh |
| X < 5b | All | 3 | 2 | 1 |
| 5 ≤ X < 10 | IA, IVA | 3 | 2 | 1 |
| Others | 2 | 1 | 1 | |
| 10 ≤ X < 30 | IA, IB, IVA, IVB | 2 | 1 | 1c |
| IIB, VB | 1 | 0 | 0 | |
| Others | 1 | 1 | 1c | |
| X ≥ 30 | All | 0 | 0 | 0 |
For SI: 1 foot = 304.8 mm.
a.Load-bearing exterior walls shall also comply with the fire-resistance rating requirements of Table 601.
c.Open parking garages complying with Section 406 shall not be required to have a fire-resistance rating.
d.The fire-resistance rating of an exterior wall is determined based upon the fire separation distance of the exterior wall and the story in which the wall is located.
e.For special requirements for Group H occupancies, see Section 415.6.
f.For special requirements for Group S aircraft hangars, see Section 412.3.1.
g.Where Table 705.8 permits nonbearing exterior walls with unlimited area of unprotected openings, the required fire-resistance rating for the exterior walls is 0 hours.
h.For a building containing only a Group U occupancy private garage or carport, the exterior wall shall not be required to have a fire-resistance rating where the fire separation distance is 5 feet (1523 mm) or greater.
i.For a Group R-3 building of Type II-B or Type V-B construction, the exterior wall shall not be required to have a fire-resistance rating where the fire separation distance is 5 feet (1523 mm) or greater.
705.6 Structural stability.
705.7 Unexposed surface temperature.
Where protected openings are not limited by Section 705.8, the limitation on the rise of temperature on the unexposed surface of exterior walls as required by ASTM E119 or UL 263 shall not apply. Where protected openings are limited by Section 705.8, the limitation on the rise of temperature on the unexposed surface of exterior walls as required by ASTM E119 or UL 263 shall not apply provided that a correction is made for radiation from the unexposed exterior wall surface in accordance with the following formula:
where:
Ae = Equivalent area of protected openings.
A = Actual area of protected openings.
Af = Area of exterior wall surface in the story under consideration exclusive of openings, on which the temperature limitations of ASTM E119 or UL 263 for walls are exceeded.
Feo = An “equivalent opening factor” derived from Figure 705.7 based on the average temperature of the unexposed wall surface and the fire-resistance rating of the wall.
FIGURE 705.7
EQUIVALENT OPENING FACTOR
705.8.1 Allowable area of openings.
The maximum area of unprotected and protected openings permitted in an exterior wall in any story of a building shall not exceed the percentages specified in Table 705.8 based on the fire separation distance of each individual story.
Exceptions:
1.In other than Group H occupancies, unlimited unprotected openings are permitted in the first storyabove grade plane where the wall faces one of the following:
1.1.A street and has a fire separation distance of more than 15 feet (4572 mm).
1.2.An unoccupied space. The unoccupied space shall be on the same lot or dedicated for public use, shall be not less than 30 feet (9144 mm) in width and shall have access from a street by a posted fire lane in accordance with the International Fire Code.
2.Buildings whose exterior bearing walls, exterior nonbearing walls and exterior primary structural frame are not required to be fire-resistance rated shall be permitted to have unlimited unprotected openings.
705.8.4 Mixed openings.
Where both unprotected and protected openings are located in the exterior wall in any story of a building, the total area of openings shall be determined in accordance with the following:
705.8.5 Vertical separation of openings.
Openings in exterior walls in adjacent stories shall be separated vertically to protect against fire spread on the exterior of the buildings where the openings are within 5 feet (1524 mm) of each other horizontally and the opening in the lower story is not a protected opening with a fire protection rating of not less than 3/4 hour. Such openings shall be separated vertically not less than 3 feet (914 mm) by spandrel girders, exterior walls or other similar assemblies that have a fire-resistance rating of not less than 1 hour, rated for exposure to fire from both sides, or by flame barriers that extend horizontally not less than 30 inches (762 mm) beyond the exterior wall. Flame barriers shall have a fire-resistance rating of not less than 1 hour. The unexposed surface temperature limitations specified in ASTM E119 or UL 263 shall not apply to the flame barriers unless otherwise required by the provisions of this code.
705.8.6 Vertical exposure.
For buildings on the same lot, opening protectives having a fire protection rating of not less than 3/4 hour shall be provided in every opening that is less than 15 feet (4572 mm) vertically above the roof of an adjacent building or structure based on assuming an imaginary line between them. The opening protectives are required where the fire separation distances from the imaginary line to each building or structure are less than 15 feet (4572 mm).
Exceptions:
1.Opening protectives are not required where the roof assembly of the adjacent building or structure has a fire-resistance rating of not less than 1 hour for a minimum distance of 10 feet (3048 mm) from the exterior wall facing the imaginary line and the entire length and span of the supporting elements for the fire-resistance-rated roof assembly has a fire-resistance rating of not less than 1 hour.
2.Buildings on the same lot and considered as portions of one building in accordance with Section 705.3 are not required to comply with Section 705.8.6.
TABLE 705.8
MAXIMUM AREA OF EXTERIOR WALL OPENINGS BASED ON FIRE SEPARATION DISTANCE AND DEGREE OF OPENING PROTECTION
| FIRE SEPARATION DISTANCE (feet) | DEGREE OF OPENING PROTECTION | ALLOWABLE AREAa |
| 0 to less than 3b, c, k | Unprotected, Nonsprinklered (UP, NS) | Not Permittedk |
| Unprotected, Sprinklered (UP, S)i | Not Permittedk | |
| Protected (P) | Not Permittedk | |
| 3 to less than 5d, e | Unprotected, Nonsprinklered (UP, NS) | Not Permitted |
| Unprotected, Sprinklered (UP, S)i | 15% | |
| Protected (P) | 15% | |
| 5 to less than 10e, f, j | Unprotected, Nonsprinklered (UP, NS) | 10%h |
| Unprotected, Sprinklered (UP, S)i | 25% | |
| Protected (P) | 25% | |
| 10 to less than 15e, f, g, j | Unprotected, Nonsprinklered (UP, NS) | 15%h |
| Unprotected, Sprinklered (UP, S)i | 45% | |
| Protected (P) | 45% | |
| 15 to less than 20f, g, j | Unprotected, Nonsprinklered (UP, NS) | 25% |
| Unprotected, Sprinklered (UP, S)i | 75% | |
| Protected (P) | 75% | |
| 20 to less than 25f, g, j | Unprotected, Nonsprinklered (UP, NS) | 45% |
| Unprotected, Sprinklered (UP, S)i | No Limit | |
| Protected (P) | No Limit | |
| 25 to less than 30f, g, j | Unprotected, Nonsprinklered (UP, NS) | 70% |
| Unprotected, Sprinklered (UP, S)i | No Limit | |
| Protected (P) | No Limit | |
| 30 or greater | Unprotected, Nonsprinklered (UP, NS) | No Limit |
| Unprotected, Sprinklered (UP, S)i | No Limit | |
| Protected (P) | No Limit |
For SI: 1 foot = 304.8 mm.
UP, NS = Unprotected openings in buildings not equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
UP, S = Unprotected openings in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
P = Openings protected with an opening protective assembly in accordance with Section 705.8.2.
a.Values indicated are the percentage of the area of the exterior wall, per story.
b.For the requirements for fire walls of buildings with differing heights, see Section 706.6.1.
c.For openings in a fire wall for buildings on the same lot, see Section 706.8.
d.The maximum percentage of unprotected and protected openings shall be 25 percent for Group R-3 occupancies.
e.Unprotected openings shall not be permitted for openings with a fire separation distance of less than 15 feet for Group H-2 and H-3 occupancies.
f.The area of unprotected and protected openings shall not be limited for Group R-3 occupancies, with a fire separation distance of 5 feet or greater.
g.The area of openings in an open parking structure with a fire separation distance of 10 feet or greater shall not be limited.
h.Includes buildings accessory to Group R-3.
i.Not applicable to Group H-1, H-2 and H-3 occupancies.
j.The area of openings in a building containing only a Group U occupancy private garage or carport with a fire separation distance of 5 feet or greater shall not be limited.
k.For openings between S-2 parking garage and Group R-2 building, see Section 705.3, Exception 2.
705.9 Joints.
705.11 Parapets.
Parapets shall be provided on exterior walls of buildings.
Exceptions: A parapet need not be provided on an exterior wall where any of the following conditions exist:
1.The wall is not required to be fire-resistance rated in accordance with Table 705.5 because of fire separation distance.
2.The building has an area of not more than 1,000 square feet (93 m2) on any floor.
3.Walls that terminate at roofs of not less than 2-hour fire-resistance-rated construction or where the roof, including the deck or slab and supporting construction, is constructed entirely of noncombustible materials.
4.One-hour fire-resistance-rated exterior walls that terminate at the underside of the roof sheathing, deck or slab, provided that:
4.1.Where the roof/ceiling framing elements are parallel to the walls, such framing and elements supporting such framing shall not be of less than 1-hour fire-resistance-rated construction for a width of 4 feet (1220 mm) for Groups R and U and 10 feet (3048 mm) for other occupancies, measured from the interior side of the wall.
4.2.Where roof/ceiling framing elements are not parallel to the wall, the entire span of such framing and elements supporting such framing shall not be of less than 1-hour fire-resistance-rated construction.
4.3.Openings in the roof shall not be located within 5 feet (1524 mm) of the 1-hour fire-resistance-rated exterior wall for Groups R and U and 10 feet (3048 mm) for other occupancies, measured from the interior side of the wall.
4.4.The entire building shall be provided with not less than a Class B roof covering.
5.In Groups R-2 and R-3 where the entire building is provided with a Class C roof covering, the exterior wall shall be permitted to terminate at the underside of the roof sheathing or deck in Types III, IV and V construction, provided that one or both of the following criteria is met:
5.1.The roof sheathing or deck is constructed of approved noncombustible materials or of fire-retardant-treated wood for a distance of 4 feet (1220 mm).
5.2.The roof is protected with 0.625-inch (16 mm) Type X gypsum board directly beneath the underside of the roof sheathing or deck, supported by not less than nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members for a minimum distance of 4 feet (1220 mm).
6.Where the wall is permitted to have not less than 25 percent of the exterior wall areas containing unprotected openings based on fire separation distance as determined in accordance with Section 705.8.
705.11.1 Parapet construction.
SECTION 706
FIRE WALLS
706.1 General.
706.1.1 Party walls.
Any wall located on a lot line between adjacent buildings, which is used or adapted for joint service between the two buildings, shall be constructed as a fire wall in accordance with Section 706. Party walls shall be constructed without openings and shall create separate buildings.
Exceptions:
1.Openings in a party wall separating an anchor building and a mall shall be in accordance with Section 402.4.2.2.1.
2.Party walls and fire walls are not required on lot lines dividing a building for ownership purposes where the aggregate height and area of the portions of the building located on both sides of the lot line do not exceed the maximum height and area requirements of this code. For the building official’s review and approval, the official shall be provided with copies of dedicated access easements and contractual agreements that permit the owners of portions of the building located on either side of the lot line access to the other side for purposes of maintaining fire and life safety systems necessary for the operation of the building.
706.3 Materials.
Fire walls shall be of any approved noncombustible materials.
Exception: Buildings of Type V construction.
706.4 Fire-resistance rating.
TABLE 706.4
FIRE WALL FIRE-RESISTANCE RATINGS
| GROUP | FIRE-RESISTANCE RATING (hours) |
| A, B, E, H-4, I, R-1, R-2, U | 3a |
| F-1, H-3b, H-5, M, S-1 | 3 |
| H-1, H-2 | 4b |
| F-2, S-2, R-3, R-4 | 2 |
706.5 Horizontal continuity.
Fire walls shall be continuous from exterior wall to exterior wall and shall extend not less than 18 inches (457 mm) beyond the exterior surface of exterior walls.
Exceptions:
1.Fire walls shall be permitted to terminate at the interior surface of combustible exterior sheathing or siding provided that the exterior wall has a fire-resistance rating of not less than 1 hour for a horizontal distance of not less than 4 feet (1220 mm) on both sides of the fire wall. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than 3/4 hour.
2.Fire walls shall be permitted to terminate at the interior surface of noncombustible exterior sheathing, exterior siding or other noncombustible exterior finishes provided that the sheathing, siding or other exterior noncombustible finish extends a horizontal distance of not less than 4 feet (1220 mm) on both sides of the fire wall.
3.Fire walls shall be permitted to terminate at the interior surface of noncombustible exterior sheathing where the building on each side of the fire wall is protected by an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2.
706.5.1 Exterior walls.
Where the fire wall intersects exterior walls, the fire-resistance rating and opening protection of the exterior walls shall comply with one of the following:
1.The exterior walls on both sides of the fire wall shall have a 1-hour fire-resistance rating with 3/4-hour protection where opening protection is required by Section 705.8. The fire-resistance rating of the exterior wall shall extend not less than 4 feet (1220 mm) on each side of the intersection of the fire wall to exterior wall. Exterior wall intersections at fire walls that form an angle equal to or greater than 180 degrees (3.14 rad) do not need exterior wall protection.
2.Buildings or spaces on both sides of the intersecting fire wall shall assume to have an imaginary lot line at the fire wall and extending beyond the exterior of the fire wall. The location of the assumed line in relation to the exterior walls and the fire wall shall be such that the exterior wall and opening protection meet the requirements set forth in Sections 705.5 and 705.8. Such protection is not required for exterior walls terminating at fire walls that form an angle equal to or greater than 180 degrees (3.14 rad).
706.5.2 Horizontal projecting elements.
Fire walls shall extend to the outer edge of horizontal projecting elements such as balconies, roof overhangs, canopies, marquees and similar projections that are within 4 feet (1220 mm) of the fire wall.
Exceptions:
1.Horizontal projecting elements without concealed spaces, provided that the exterior wall behind and below the projecting element has not less than 1-hour fire-resistance-rated construction for a distance not less than the depth of the projecting element on both sides of the fire wall. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than 3/4 hour.
2.Noncombustible horizontal projecting elements with concealed spaces, provided that a minimum 1-hour fire-resistance-rated wall extends through the concealed space. The projecting element shall be separated from the building by not less than 1-hour fire-resistance-rated construction for a distance on each side of the fire wall equal to the depth of the projecting element. The wall is not required to extend under the projecting element where the building exterior wall is not less than 1-hour fire-resistance rated for a distance on each side of the fire wall equal to the depth of the projecting element. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than 3/4 hour.
3.For combustible horizontal projecting elements with concealed spaces, the fire wall need only extend through the concealed space to the outer edges of the projecting elements. The exterior wall behind and below the projecting element shall be of not less than 1-hour fire-resistance-rated construction for a distance not less than the depth of the projecting elements on both sides of the fire wall. Openings within such exterior walls shall be protected by opening protectives having a fire protection rating of not less than 3/4 hour.
706.6 Vertical continuity.
Fire walls shall extend from the foundation to a termination point not less than 30 inches (762 mm) above both adjacent roofs.
Exceptions:
2.Two-hour fire-resistance-rated walls shall be permitted to terminate at the underside of the roof sheathing, deck or slab, provided that:
2.1.The lower roof assembly within 4 feet (1220 mm) of the wall has not less than a 1-hour fire-resistance rating and the entire length and span of supporting elements for the rated roof assembly has a fire-resistance rating of not less than 1 hour.
2.2.Openings in the roof shall not be located within 4 feet (1220 mm) of the fire wall.
2.3.Each building shall be provided with not less than a Class B roof covering.
3.Walls shall be permitted to terminate at the underside of noncombustible roof sheathing, deck or slabs where both buildings are provided with not less than a Class B roof covering. Openings in the roof shall not be located within 4 feet (1220 mm) of the fire wall.
4.In buildings of Types III, IV and V construction, walls shall be permitted to terminate at the underside of combustible roof sheathing or decks, provided that all of the following requirements are met:
4.1.Roof openings are not less than 4 feet (1220 mm) from the fire wall.
4.2.The roof is covered with a minimum Class B roof covering.
4.3.The roof sheathing or deck is constructed of fire-retardant-treated wood for a distance of 4 feet (1220 mm) on both sides of the wall or the roof is protected with 5/8-inch (15.9 mm) Type X gypsum board directly beneath the underside of the roof sheathing or deck, supported by not less than 2-inch (51 mm) nominal ledgers attached to the sides of the roof framing members for a distance of not less than 4 feet (1220 mm) on both sides of the fire wall.
5.In buildings designed in accordance with Section 510.2, fire walls located above the 3-hour horizontal assembly required by Section 510.2, Item 1 shall be permitted to extend from the top of this horizontal assembly.
6.Buildings with sloped roofs in accordance with Section 706.6.2.
706.6.1 Stepped buildings.
Where a fire wall also serves as an exterior wall for a building and separates buildings having different roof levels, such wall shall terminate at a point not less than 30 inches (762 mm) above the lower roof level. Exterior walls above the fire wall extending more than 30 inches (762 mm) above the lower roof shall be of not less than 1-hour fire-resistance-rated construction from both sides with openings protected by fire assemblies having a fire protection rating of not less than 3/4 hour. Portions of the exterior walls greater than 15 feet (4572 mm) above the lower roof shall be of nonfire-resistance-rated construction unless otherwise rated construction is required by other provisions of this code.
Exception:A fire wallserving as part of an exterior wall that separates buildings having different roof levels shall be permitted to terminate at the underside of the roof sheathing, deck or slab of the lower roof, provided that Items 1, 2 and 3 are met. The exterior wall above the fire wall is not required to be of fire-resistance-rated construction unless required by other provisions of this code.
1.The lower roof assembly within 10 feet (3048 mm) of thefire wall has not less than a 1-hour fire-resistance rating.
2.The entire length and span of supporting elements for the rated roof assembly shall have a fire-resistance rating of not less than 1 hour.
3.Openings in the lower roof shall not be located within 10 feet (3048 mm) of the fire wall.
706.6.2 Buildings with sloped roofs.
706.7 Combustible framing in fire walls.
706.11 Ducts and air transfer openings.
Ducts and air transfer openings shall not penetrate fire walls.
SECTION 707
FIRE BARRIERS
707.2 Materials.
707.3 Fire-resistance rating.
707.3.10 Fire areas.
TABLE 707.3.10
FIRE-RESISTANCE-RATING REQUIREMENTS FOR FIRE BARRIERS, FIRE WALLS OR HORIZONTAL ASSEMBLIES BETWEEN FIRE AREAS
| OCCUPANCY GROUP | FIRE-RESISTANCE RATING (hours) |
| H-1, H-2 | 4 |
| F-1, H-3, S-1 | 3 |
| A, B, E, F-2, H-4, H-5, I, M, R, S-2 | 2 |
| U | 1 |
707.4 Exterior walls.
Where exterior walls serve as a part of a required fire-resistance-rated shaft, or separation or enclosure for a stairway, ramp or exit passageway, such walls shall comply with the requirements of Section 705 for exterior walls and the fire-resistance-rated enclosure or separation requirements shall not apply.
Exceptions:
1.Exterior walls required to be fire-resistance rated in accordance with Section 1021 for exterior egress balconies, Section 1023.7 for interior exit stairways and ramps, Section 1024.8 forexit passageways and Section 1027.6 for exterior exit stairways and ramps.
2.Exterior walls required to be fire-resistance rated in accordance with Section 1207 of the International Fire Code for enclosure of energy storage systems.
707.5 Continuity.
Fire barriers shall extend from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, slab or deck above and shall be securely attached thereto. Such fire barriers shall be continuous through concealed space, such as the space above a suspended ceiling. Joints and voids at intersections shall comply with Sections 707.8 and 707.9
Exceptions:
1.Shaft enclosures shall be permitted to terminate at a top enclosure complying with Section 713.12.
2.Interior exit stairway and ramp enclosures required by Section 1023 and exit access stairway and ramp enclosures required by Section 1019 shall be permitted to terminate at a top enclosure complying with Section 713.12.
3.An exit passageway enclosure required by Section 1024.3 that does not extend to the underside of the roof sheathing, slab or deck above shall be enclosed at the top with construction of the same fire-resistance ratingas required for the exit passageway.
707.5.1 Supporting construction.
The supporting construction for a fire barrier shall be protected to afford the required fire-resistance rating of the fire barrier supported. Hollow vertical spaces within a fire barrier shall be fireblocked in accordance with Section 718.2 at every floor level.
Exceptions:
1.The maximum required fire-resistance rating for assemblies supporting fire barriers separating tank storage as provided for in Section 415.9.1.2 shall be 2 hours, but not less than required by Table 601 for the building construction type.
2.Supporting construction for 1-hour fire barriers required by Table 509.1 in buildings of Types IIB, IIIB and VB construction is not required to be fire-resistance rated unless required by other sections of this code.
707.6 Openings.
Openings in a fire barrier shall be protected in accordance with Section 716. Openings shall be limited to a maximum aggregate width of 25 percent of the length of the wall, and the maximum area of any single opening shall not exceed 156 square feet (15 m2). Openings in enclosures for exit access stairways and ramps, interior exit stairways and ramps and exit passageways shall also comply with Sections 1019, 1023.4 and 1024.5, respectively.
Exceptions:
1.Openings shall not be limited to 156 square feet (15 m2) where adjoining floor areas are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
2.Openings shall not be limited to 156 square feet (15 m2) or an aggregate width of 25 percent of the length of the wall where the opening protective is a fire door serving enclosures forexit access stairways and ramps, andinterior exit stairways and ramps.
3.Openings shall not be limited to 156 square feet (15 m2) or an aggregate width of 25 percent of the length of the wall where the opening protective has been tested in accordance with ASTM E119 or UL 263 and has a minimum fire-resistance rating not less than the fire-resistance rating of the wall.
4.Fire window assemblies permitted in atrium separation walls shall not be limited to a maximum aggregate width of 25 percent of the length of the wall.
5.Openings shall not be limited to 156 square feet (15 m2) or an aggregate width of 25 percent of the length of the wall where the opening protective is a fire door assembly in a fire barrier separating an enclosure for exit access stairways andramps, and interior exit stairways and ramps from an exit passageway in accordance with Section 1023.3.1.
707.9 Voids at intersections.
SECTION 708
FIRE PARTITIONS
708.1 General.
The following wall assemblies shall comply with this section:
1.Separation walls as required by Section 420.2 for Group I-1 and Group R occupancies.
2.Walls separating tenant spaces in covered and open mall buildings as required by Section 402.4.2.1.
4.Enclosed elevator lobby separation as required by Section 3006.3.
6.Walls separating ambulatory care facilities from adjacent spaces, corridors or tenant as required by Section 422.2.
7.Walls separating dwelling and sleeping units in Groups R-1 and R-2 in accordance with Sections 907.2.8.1 and 907.2.9.1.
708.2 Materials.
708.3 Fire-resistance rating.
Fire partitions shall have a fire-resistance rating of not less than 1 hour.
Exceptions:
1.Corridor walls permitted to have a 1/2-hour fire-resistance rating by Table 1020.2.
2.Dwelling unit and sleeping unit separations in buildings of Types IIB, IIIB and VB construction shall have fire-resistance ratings of not less than 1/2 hour in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
708.4 Continuity.
Fire partitions shall extend from the top of the foundation or floor/ceiling assembly below and be securely attached to one of the following:
1.The underside of the floor or roof sheathing, deck or slab above.
2.The underside of a floor/ceiling or roof/ceiling assembly having a fire-resistance rating that is not less than the fire-resistance rating of the fire partition.
Exceptions:
1.Fire partitions shall not be required to extend into a crawl space below where the floor above the crawl space has a minimum 1-hour fire-resistance rating.
2.Fire partitions serving as a corridor wall shall not be required to extend above the lower membrane of a corridor ceiling provided that the corridor ceiling membrane is equivalent to corridor wall membrane, and either of the following conditions is met:
2.1.The room-side membrane of the corridor wall extends to the underside of the floor or roof sheathing, deck or slab of a fire-resistance-rated floor or roof above.
2.2.The building is equipped with an automatic sprinkler system installed throughout in accordance with Section 903.3.1.1 or 903.3.1.2, including automatic sprinklers installed in the space between the top of the fire partition and underside of the floor or roof sheathing, deck or slab above.
3.Fire partitions serving as a corridor wall shall be permitted to terminate at the upper membrane of the corridor ceiling assembly where the corridor ceiling is constructed as required for the corridor wall.
4.Fire partitions separating tenant spaces in a covered or open mall building complying with Section 402.4.2.1 shall not be required to extend above the underside of a ceiling. Such ceiling shall not be required to be part of a fire-resistance-rated assembly, and the attic or space above the ceiling at tenant separation walls shall not be required to be subdivided by fire partitions.
708.4.1 Supporting construction.
The supporting construction for a fire partition shall have a fire-resistance rating that is equal to or greater than the required fire-resistance rating of the supported fire partition.
Exception: In buildings of Types IIB, IIIB and VB construction, the supporting construction requirement shall not apply to fire partitions separating tenant spaces in covered and open mall buildings, fire partitions separating dwelling units, fire partitions separating sleeping units, fire partitions serving as corridor walls, fire partitions separating ambulatory care facilities from adjacent spaces or corridors, fire partitions separating dwelling and sleeping units from Group R-1 and R-2 occupancies and fire partitionsseparating vestibules from the level of exit discharge.
708.4.2 Fireblocks and draftstops in combustible construction.
In combustible construction where fire partitions do not extend to the underside of the floor or roof sheathing, deck or slab above, the space above and along the line of the fire partition shall be provided with one of the following:
1.Fireblocking up to the underside of the floor or roof sheathing, deck or slab above using materials complying with Section 718.2.1.
2.Draftstopping up to the underside of the floor or roof sheathing, deck or slab above using materials complying with Section 718.3.1 for floors or Section 718.4.1 for attics.
Exceptions:
1.Buildings equipped with an automatic sprinkler system installed throughout in accordance with Section 903.3.1.1, or in accordance with Section 903.3.1.2 provided that protection is provided in the space between the top of the fire partition and underside of the floor or roof sheathing, deck or slab above as required for systems complying with Section 903.3.1.1.
2.Where corridor walls provide a sleeping unit or dwelling unit separation, draftstopping shall only be required above one of the corridor walls.
3.In Group R-2 occupancies with fewer than four dwelling units, fireblocking and draftstopping shall not be required.
4.In Group R-2 occupancies up to and including four stories in height in buildings not exceeding 60 feet (18 288 mm) in height above grade plane, theatticspace shall be subdivided by draftstops into areas not exceeding 3,000 square feet (279 m2) or above every two dwelling units, whichever is smaller.
5.In Group R-3 occupancies with fewer than three dwelling units, fireblocking and draftstopping shall not be required in floor assemblies.
SECTION 709
SMOKE BARRIERS
709.1 General.
709.2 Materials.
Smoke barriers shall be of materials permitted by the building type of construction.
709.3 Fire-resistance rating.
A 1-hour fire-resistance rating is required for smoke barriers.
709.4 Continuity.
Smoke barriers shall form an effective membrane continuous from the top of the foundation or floor/ceiling assembly below to the underside of the floor or roof sheathing, deck or slab above, including continuity through concealed spaces, such as those found above suspended ceilings, and interstitial structural and mechanical spaces. The supporting construction shall be protected to afford the required fire-resistance rating of the wall or floor supported in buildings of other than Type IIB, IIIB or VB construction. Smoke-barrier walls used to separate smoke compartments shall comply with Section 709.4.1. Smoke-barrier walls used to enclose areas of refuge in accordance with Section 1009.6.4 or to enclose elevator lobbies in accordance with Section 405.4.3, 3007.6.2, or 3008.6.2 shall comply with Section 709.4.2.
Exception: Smoke-barrier walls are not required in interstitial spaces where such spaces are designed and constructed with ceilings or exterior walls that provide resistance to the passage of fire and smoke equivalent to that provided by the smoke-barrier walls.
709.4.1 Smoke-barrier assemblies separating smoke compartments.
709.4.2 Smoke-barrier walls enclosing areas of refuge or elevator lobbies.
709.5 Openings.
Openings in a smoke barrier shall be protected in accordance with Section 716.
Exceptions:
1.In Group I-1, Condition 2, Group I-2 and ambulatory care facilities, where a pair of opposite-swinging doors are installed across a corridor in accordance with Section 709.5.1, the doors shall not be required to be protected in accordance with Section 716. The doors shall be close fitting within operational tolerances, and shall not have a center mullion or undercuts in excess of 3/4 inch (19.1 mm), louvers or grilles. The doors shall have head and jamb stops, and astragals or rabbets at meeting edges. Where permitted by the door manufacturer’s listing, positive-latching devices are not required. Factory-applied or field-applied protective plates are not required to be labeled.
2.In Group I-1, Condition 2, Group I-2 and ambulatory care facilities, special purpose horizontal sliding, accordion or folding doors installed in accordance with Section 1010.3.3 and protected in accordance with Section 716.
709.5.1 Group I-2 and ambulatory care facilities.
SECTION 710
SMOKE PARTITIONS
710.1 General.
710.2 Materials.
The walls shall be of materials permitted by the building type of construction.
710.3 Fire-resistance rating.
710.4 Continuity.
710.5.1 Windows.
710.5.2.2 Smoke and draft control doors.
710.5.3 Pass-through openings in Group I-2, Condition 2.
1.The smoke compartmentin which the pass-through openings occur does not contain a patient care suite or sleeping room.
2.Pass-through openings are installed in a wall, door or vision panel that is not required to have afire-resistance rating.
3.The top of the pass-through opening is located a maximum of 48 inches (1219 mm) above the floor.
4. The aggregate area of all such pass-through openings within a single room shall not exceed 80 square inches (0.05 m2).
710.6 Penetrations.
The space around penetrating items shall be filled with an approved material to limit the free passage of smoke.
710.7 Joints.
SECTION 711
FLOOR AND ROOF ASSEMBLIES
711.2 Horizontal assemblies.
711.2.1 Materials.
711.2.3 Supporting construction.
The supporting construction shall be protected to afford the required fire-resistance rating of the horizontal assembly supported.
Exception: In buildings of Type IIB, IIIB or VB construction, the construction supporting the horizontal assembly is not required to be fire-resistance rated at the following:
1.Horizontal assemblies at the separations of incidental uses as specified by Table 509.1 provided that the required fire-resistance rating does not exceed 1 hour.
2.Horizontal assemblies at the separations of dwelling units and sleeping units as required by Section 420.3.
3.Horizontal assemblies at smoke barriers constructed in accordance with Section 709.
711.2.4 Fire-resistance rating.
711.2.4.3 Dwelling units and sleeping units.
Horizontal assemblies serving as dwelling or sleeping unit separations in accordance with Section 420.3 shall be not less than 1-hour fire-resistance-rated construction.
Exception: Horizontal assemblies separating dwelling units and sleeping units shall be not less than 1/2-hour fire-resistance-rated construction in a building of Types IIB, IIIB and VB construction, where the building is equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
711.2.4.6 Other separations.
711.2.5 Ceiling panels.
Where the weight of lay-in ceiling panels, used as part of fire-resistance-rated floor/ceiling or roof/ceiling assemblies, is not adequate to resist an upward force of 1 pound per square foot (48 Pa), wire or other approved devices shall be installed above the panels to prevent vertical displacement under such upward force.
711.2.6 Unusable space.
In 1-hour fire-resistance-rated floor/ceiling assemblies, the ceiling membrane is not required to be installed over unusable crawl spaces. In 1-hour fire-resistance-rated roof assemblies, the floor membrane is not required to be installed where unusable attic space occurs above.
711.3 Nonfire-resistance-rated floor and roof assemblies.
711.3.1 Materials.
SECTION 712
VERTICAL OPENINGS
712.1 General.
712.1.2 Individual dwelling unit.
712.1.3 Escalator openings.
712.1.3.1 Opening size.
712.1.3.2 Automatic shutters.
712.1.5 Joints.
712.1.5.1 Joints in or between horizontal assemblies.
712.1.5.2 Joints in or between nonfire-resistance-rated floor assemblies.
Joints in or between floor assemblies without a required fire-resistance rating shall be permitted where they comply with one of the following:
1.Thejointshall be concealed within the cavity of a wall.
2.Thejointshall be located above a ceiling.
3.The jointshall be sealed, treated or covered with an approved material or system to resist the free passage of flame and the products of combustion.
712.1.9 Two-story openings.
In other than Groups I-2 and I-3, a vertical opening that is not used as one of the applications specified in this section shall be permitted if the opening complies with all of the following items:
1.Does not connect more than two stories.
2.Does not penetrate a horizontal assembly that separatesfire areas or smoke barriers that separate smoke compartments.
3.Is not concealed within the construction of a wall or a floor/ceiling assembly.
4.Is not open to a corridor in Group I and R occupancies.
5.Is not open to a corridor on nonsprinklered floors.
6.Is separated from floor openings and air transfer openings serving other floors by construction conforming to required shaft enclosures.
712.1.10 Parking garages.
712.1.13 Openings.
712.1.13.1 Horizontal fire door assemblies.
712.1.15 Skylights.
712.1.16 Openings otherwise permitted.
SECTION 713
SHAFT ENCLOSURES
713.3 Materials.
713.4 Fire-resistance rating.
713.5 Continuity.
713.7 Openings.
713.7.1 Prohibited openings.
713.8 Penetrations.
713.8.1 Prohibited penetrations.
713.11 Enclosure at the bottom.
Shafts that do not extend to the bottom of the building or structure shall comply with one of the following:
1.Be enclosed at the lowest level with construction of the same fire-resistance rating as the lowest floor through which the shaft passes, but not less than the rating required for the shaft enclosure.
2.Terminate in a room having a use related to the purpose of the shaft. The room shall be separated from the remainder of the building by fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both. The fire-resistance rating and opening protectives shall be not less than the protection required for the shaft enclosure.
3.Be protected by approved fire dampers installed in accordance with their listing at the lowest floor level within the shaft enclosure.
Exceptions:
1.The fire-resistance-rated room separation is not required, provided that the only openings in or penetrations of the shaft enclosure to the interior of the building occur at the bottom. The bottom of the shaft shall be closed off around the penetrating items with materials permitted by Section 718.3.1 for draftstopping, or the room shall be provided with an approved automatic sprinkler system.
2.A shaft enclosure containing a waste or linen chute shall not be used for any other purpose and shall discharge in a room protected in accordance with Section 713.13.4.
3.The fire-resistance-rated room separation and the protection at the bottom of the shaft are not required provided that there are no combustibles in the shaft and there are no openings or other penetrations through the shaft enclosure to the interior of the building.
713.12 Enclosure at top.
The top of shaft enclosures shall comply with one of the following:
1.Extend to the underside of the roof sheathing, deck or slab of the building, and the roof assembly shall comply with the requirements for the type of construction as specified in Table 601.
2.Terminate below the roof assembly and be enclosed at the top with construction of the same fire-resistance rating as the topmost floor penetrated by the shaft, but not less than the fire-resistance rating required for the shaft enclosure.
3.Extend past the roof assembly and comply with the requirements of Section 1511.
713.12.1 Penthouse mechanical rooms.
713.13 Waste, recycling and linen chutes and incinerator rooms.
Waste, recycling and linen chutes shall comply with the provisions of NFPA 82, Chapter 6 and shall meet the requirements of Sections 712 and 713.13.1 through 713.13.6. Incinerator rooms shall meet the provisions of Sections 713.13.4 and 713.13.5.
Exception: Chutes serving and contained within a single dwelling unit.
713.13.1 Waste, recycling and linen chute enclosures.
713.13.2 Materials.
713.13.3 Chute access rooms.
713.13.4 Chute discharge room.
SECTION 714
PENETRATIONS
714.1 Scope.
714.1.1 Ducts and air transfer openings.
714.2 Installation.
A listed penetration firestop system shall be installed in accordance with the manufacturer’s installation instructions and the listing criteria.
714.3 Installation details.
Where sleeves are used, they shall be securely fastened to the assembly penetrated. The space between the item contained in the sleeve and the sleeve itself and any space between the sleeve and the assembly penetrated shall be protected in accordance with this section. Insulation and coverings on or in the penetrating item shall not penetrate the assembly unless the specific material used has been tested as part of the assembly in accordance with this section.
714.4 Fire-resistance-rated walls.
714.4.1 Through penetrations.
Through penetrations of fire-resistance-rated walls shall comply with Section 714.4.1.1 or 714.4.1.2.
Exception: Where the penetrating items are steel, ferrous or copper pipes, tubes or conduits, the annular space between the penetrating item and the fire-resistance-rated wall is permitted to be protected by either of the following measures:
1.In concrete or masonry walls where the penetrating item is a maximum 6-inch (152 mm) nominal diameter and the area of the opening through the wall does not exceed 144 square inches (0.0929 m2), concrete, grout or mortar is permitted where installed the full thickness of the wall or the thickness required to maintain the fire-resistance rating.
2.The material used to fill the annular space shall prevent the passage of flame and hot gases sufficient to ignite cotton waste when subjected to ASTM E119 or UL 263 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water at the location of the penetration for the time period equivalent to the fire-resistance rating of the construction penetrated.
714.4.1.1 Fire-resistance-rated assemblies.
714.4.1.2 Through-penetration firestop system.
714.4.2 Membrane penetrations.
Membrane penetrations shall comply with Section 714.4.1. Where walls or partitions are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.
Exceptions:
1.Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that do not exceed 16 square inches (0.0 103 m2) in area, provided that the aggregate area of the openings through the membrane does not exceed 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm). Such boxes on opposite sides of the wall or partition shall be separated by one of the following:
1.1.By a horizontal distance of not less than 24 inches (610 mm) where the wall or partition is constructed with individual noncommunicating stud cavities.
1.2.By a horizontal distance of not less than the depth of the wall cavity where the wall cavity is filled with cellulose loose-fill, rockwool or slag mineral wool insulation.
1.3.By solid fireblocking in accordance with Section 718.2.1.
1.4.By protecting both outlet boxes with listed putty pads.
1.5.By other listed materials and methods.
2.Membrane penetrations by listed electrical boxes of any material, provided that such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the wall membrane and the box shall not exceed 1/8 inch (3.2 mm) unless listed otherwise. Such boxes on opposite sides of the wall or partition shall be separated by one of the following:
3.Membrane penetrations by electrical boxes of any size or type, that have been listed as part of a wall opening protective material system for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
4.Membrane penetrations by boxes other than electrical boxes, provided that such penetrating items and the annular space between the wall membrane and the box, are protected by an approved membrane penetration firestop system installed as tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water, and shall have an F and T rating of not less than the required fire-resistance rating of the wall penetrated and be installed in accordance with their listing.
5.The annular space created by the penetration of an automatic sprinkler, provided that it is covered by a metal escutcheon plate.
6.Membrane penetrations of maximum 2-hour fire-resistance-rated walls and partitions by steel electrical boxes that exceed 16 square inches (0.0 103 m2) in area, or steel electrical boxes of any size having an aggregate area through the membrane exceeding 100 square inches (0.0645 m2) in any 100 square feet (9.29 m2) of wall area, provided that such penetrating items are protected by listed putty pads or other listed materials and methods, and installed in accordance with the listing.
714.4.3 Dissimilar materials.
714.5 Horizontal assemblies.
714.5.1 Through penetrations.
Through penetrations of horizontal assemblies shall comply with Section 714.5.1.1 or 714.5.1.2.
Exceptions:
1.Penetrations by steel, ferrous or copper conduits, pipes, tubes or vents or concrete or masonry items through a single fire-resistance-rated floor assembly where the annular space is protected with materials that prevent the passage of flame and hot gases sufficient to ignite cotton waste when subjected to ASTM E119 or UL 263 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water at the location of the penetration for the time period equivalent to the fire-resistance rating of the construction penetrated. Penetrating items with a maximum 6-inch (152 mm) nominal diameter shall not be limited to the penetration of a single fire-resistance-rated floor assembly, provided that the aggregate area of the openings through the assembly does not exceed 144 square inches (92 900 mm2) in any 100 square feet (9.3 m2) of floor area.
2.Penetrations in a single concrete floor by steel, ferrous or copper conduits, pipes, tubes or vents with a maximum 6-inch (152 mm) nominal diameter, provided that the concrete, grout or mortar is installed the full thickness of the floor or the thickness required to maintain the fire-resistance rating. The penetrating items shall not be limited to the penetration of a single concrete floor, provided that the area of the opening through each floor does not exceed 144 square inches (92 900 mm2).
3.Penetrations by listed electrical boxes of any material, provided that such boxes have been tested for use in fire-resistance-rated assemblies and installed in accordance with the instructions included in the listing.
714.5.1.1 Fire-resistance-rated assemblies.
714.5.1.2 Through-penetration firestop system.
Through penetrations shall be protected by an approved through-penetration firestop system installed and tested in accordance with ASTM E814 or UL 1479, with a minimum positive pressure differential of 0.01 inch of water (2.49 Pa). The system shall have an F rating/T rating of not less than 1 hour but not less than the required rating of the floor penetrated.
Exceptions:
1.Floor penetrations contained and located within the cavity of a wall above the floor or below the floor do not require a T rating.
2.Floor penetrations by floor drains, tub drains or shower drains contained and located within the concealed space of a horizontal assembly do not require a T rating.
3.Floor penetrations of maximum 4-inch (102 mm) nominal diameter metal conduit or tubing penetrating directly into metal-enclosed electrical power switchgear do not require a T rating.
714.5.2 Membrane penetrations.
Penetrations of membranes that are part of a horizontal assembly shall comply with Section 714.5.1.1 or 714.5.1.2. Where floor/ceiling assemblies are required to have a fire-resistance rating, recessed fixtures shall be installed such that the required fire resistance will not be reduced.
Exceptions:
1.Membrane penetrations by steel, ferrous or copper conduits, pipes, tubes or vents, or concrete or masonry items where the annular space is protected either in accordance with Section 714.5.1 or to prevent the free passage of flame and the products of combustion. The aggregate area of the openings through the membrane shall not exceed 100 square inches (64 500 mm2) in any 100 square feet (9.3 m2) of ceiling area in assemblies tested without penetrations.
2.Ceiling membrane penetrations of maximum 2-hour horizontal assemblies by steel electrical boxes that do not exceed 16 square inches (10 323 mm2) in area, provided that the aggregate area of such penetrations does not exceed 100 square inches (44 500 mm2) in any 100 square feet (9.29 m2) of ceiling area, and the annular space between the ceiling membrane and the box does not exceed 1/8 inch (3.2 mm).
3.Membrane penetrations by electrical boxes of any size or type, that have been listed as part of an opening protective material system for use in horizontal assemblies and are installed in accordance with the instructions included in the listing.
4.Membrane penetrations by listed electrical boxes of any material, provided that such boxes have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing. The annular space between the ceiling membrane and the box shall not exceed 1/8 inch (3.2 mm) unless listed otherwise.
5.The annular space created by the penetration of a fire sprinkler, provided that it is covered by a metal escutcheon plate.
6.Noncombustible items that are cast into concrete building elements and that do not penetrate both top and bottom surfaces of the element.
7.The ceiling membrane of a maximum 2-hour fire-resistance-rated horizontal assemblyis permitted to be interrupted with the double wood top plate of a wall assembly that is sheathed with Type X gypsum wallboard, provided that all penetrating items through the double top plates are protected in accordance with Section 714.5.1.1 or 714.5.1.2 and the ceiling membrane is tight to the top plates.
8.Ceiling membrane penetrations by listed luminaires (light fixtures) or by luminaires protected with listed materials, which have been tested for use in fire-resistance-rated assemblies and are installed in accordance with the instructions included in the listing.
714.5.3 Dissimilar materials.
714.5.4 Penetrations in smoke barriers.
Penetrations in smoke barriers shall be protected by an approved through-penetration firestop system installed and tested in accordance with the requirements of UL 1479 for air leakage. The L rating of the system measured at 0.30 inch (7.47 Pa) of water in both the ambient temperature and elevated temperature tests shall not exceed either of the following:
1.5.0 cfm per square foot (0.025 m3/ s × m2) of penetration opening for each through-penetration firestop system.
2.A total cumulative leakage of 50 cfm (0.024 m3/s) for any 100 square feet (9.3 m2) of wall area, or floor area.
714.6 Nonfire-resistance-rated assemblies.
714.6.1 Noncombustible penetrating items.
714.6.2 Penetrating items.
715.1 General.
715.2 Installation.
715.3 Fire-resistance-rated assembly intersections.
Joints installed in or between fire-resistance-rated walls, floor or floor/ceiling assemblies and roofs or roof/ceiling assemblies shall be protected by an approved fire-resistant joint system designed to resist the passage of fire for a time period not less than the required fire-resistance rating of the wall, floor or roof in or between which the system is installed.
Exception: Fire-resistant joint systems shall not be required for joints in the following locations:
1.Floors within a single dwelling unit.
2.Floors where the joint is protected by a shaft enclosure in accordance with Section 713.
3.Floors withinatriums where the space adjacent to the atrium is included in the volume of the atrium for smoke control purposes.
4.Floors within malls.
5.Floors and ramps within parking garages or structures constructed in accordance with Sections 406.5 and 406.6.
6.Mezzanine floors.
7.Walls that are permitted to have unprotected openings.
8.Roofs where openings are permitted.
9.Control joints not exceeding a maximum width of 0.625 inch (15.9 mm) and tested in accordance with ASTM E119 or UL 263.
10.The intersection of exterior curtain wall assemblies and the roof slab or roof deck.
715.3.1 Fire test criteria.
Fire-resistant joint systems shall be tested in accordance with the requirements of either ASTM E1966 or UL 2079. Nonsymmetrical wall joint systems shall be tested with both faces exposed to the furnace, and the assigned fire-resistance rating shall be the shortest duration obtained from the two tests. Where evidence is furnished to show that the wall was tested with the least fire-resistant side exposed to the furnace, subject to acceptance of the building official, the wall need not be subjected to tests from the opposite side.
Exception: For exterior walls with a horizontal fire separation distance greater than 10 feet (3048 mm), the joint system shall be required to be tested for interior fire exposure only.
715.4 Exterior curtain wall/fire-resistance-rated floor intersections.
Voids created at the intersection of exterior curtain wall assemblies and fire-resistance-rated floor or floor/ceiling assemblies shall be protected with an approved perimeter fire containment system to prevent the interior spread of fire. Such systems shall provide an F rating for a time period not less than the fire-resistance rating of the floor or floor/ceiling assembly.
715.4.1 Fire test criteria.
Exception: Voids created at the intersection of the exterior curtain wall assemblies and floor assemblies where the vision glass extends to the finished floor level shall be permitted to be protected with an approved material to prevent the interior spread of fire. Such material shall be securely installed and capable of preventing the passage of flame and hot gases sufficient to ignite cotton waste where subjected to ASTM E119 time-temperature fire conditions under a minimum positive pressure differential of 0.01 inch (0.254 mm) of water column (2.5 Pa) for the time period not less than the fire-resistance rating of the floor assembly.
715.5 Exterior curtain wall/nonfire-resistance-rated floor assembly intersections.
715.6 Exterior curtain wall/vertical fire barrier intersections.
715.7 Curtain wall spandrels.
715.8 Joints and voids in smoke barriers.
SECTION 716
OPENING PROTECTIVES
716.1 General.
TABLE 716.1(1)
MARKING FIRE-RATED GLAZING ASSEMBLIES
TABLE 716.1(2)
OPENING FIRE PROTECTION ASSEMBLIES, RATINGS AND MARKINGS
For SI: 1 square inch = 645.2 mm.
a.Fire-resistance-rated glazing tested to ASTM E119 in accordance with Section 716.1.2.3 shall be permitted, in the maximum size tested.
b.Under the column heading “Fire-rated glazing marking door vision panel,” W refers to the fire-resistance rating of the glazing, not the frame.
c.See Section 716.1.2.2.1 and Table 716.1(1) for additional permitted markings.
➡
d.Two doors, each with a fire protection rating of 11/2 hours, installed on opposite sides of the same opening in a fire wall, shall be deemed equivalent in fire protection rating to one 3-hour fire door.
h.Fire-protection-rated glazing is not permitted for fire barriers required by Section 1207 of the International Fire Code to enclose energy storage systems. Fire-resistance-rated glazing assemblies tested to ASTM E119 or UL 263, as specified in Section 716.1.2.3, shall be permitted.
i.Two doors, each with a fire rating of 20 minutes, installed on opposite sides of the same opening in a fire partition, shall be deemed equivalent in fire protection rating to one 45-minute fire door.
TABLE 716.1(3)
FIRE WINDOW ASSEMBLY FIRE PROTECTION RATINGS
NP = Not Permitted.
a.Not permitted except fire-resistance-rated glazing assemblies tested to ASTM E119 or UL 263, as specified in Section 716.1.2.3.
b.XXX = The fire rating duration period in minutes, which shall be equal to the fire-resistance rating required for the wall assembly.
c.Fire-protection-rated glazing is not permitted for fire barriers required by Section 1207 of the International Fire Code to enclose energy storage systems. Fire-resistance-rated glazing assemblies tested to ASTM E119 or UL 263, as specified in Section 716.1.2.3, shall be permitted.
716.1.1 Alternative methods for determining fire protection ratings.
The application of any of the alternative methods specified in this section shall be based on the fire exposure and acceptance criteria specified in NFPA 252, NFPA 257, UL 9, UL 10B or UL 10C. The required fire resistance of an opening protective shall be permitted to be established by any of the following methods or procedures:
1.Designs documented in approved sources.
2.Calculations performed in an approved manner.
3.Engineering analysis based on a comparison of opening protective designs having fire protection ratings as determined by the test procedures set forth in NFPA 252, NFPA 257, UL 9, UL 10B or UL 10C.
4.Alternative protection methods as allowed by Section 104.11.
716.1.2 Glazing.
716.1.2.2 Marking fire-rated glazing assemblies.
716.1.2.2.1 Fire-rated glazing identification.
716.1.2.2.2 Fire-protection-rated glazing identification.
716.1.2.2.4 Fire-rated glazing that exceeds the code requirements.
716.1.2.3 Fire-resistance-rated glazing.
716.1.2.3.1 Glazing in fire door and fire window assemblies.
716.2 Fire door assemblies.
716.2.1 Testing requirements.
716.2.1.1 Side-hinged or pivoted swinging doors.
716.2.1.2 Other types of assemblies.
716.2.1.3 Glazing in transoms lights and sidelights in corridors and smoke barriers.
716.2.2 Performance requirements.
716.2.2.1 Door assemblies in corridors and smoke barriers.
Fire door assemblies required to have a minimum fire protection rating of 20 minutes where located in corridor walls or smoke barrier walls having a fire-resistance rating in accordance with Table 716.1(2) shall be tested in accordance with NFPA 252 or UL 10C without the hose stream test.
Exceptions:
1.Viewports that require a hole not larger than 1 inch (25 mm) in diameter through the door, have not less than a 0.25-inch-thick (6.4 mm) glass disc and the holder is of metal that will not melt out where subject to temperatures of 1,700°F (927°C).
2.Corridor door assemblies in occupancies of Group I-2 shall be in accordance with Section 407.3.1.
3.Unprotected openings shall be permitted for corridors in multitheater complexes where each motion picture auditorium has not fewer than one-half of its required exit or exit access doorways opening directly to the exterior or into an exit passageway.
4.Horizontal sliding doors in smoke barriers that comply with Sections 408.6 and 408.8.4 in occupancies in Group I-3.
716.2.2.1.1 Smoke and draft control.
716.2.2.2 Door assemblies in other fire partitions.
716.2.2.3 Doors in interior exit stairways and ramps and exit passageways.
Fire door assemblies in interior exit stairways and ramps and exit passageways shall have a maximum transmitted temperature rise of not more than 450°F (250°C) above ambient at the end of 30 minutes of standard fire test exposure.
716.2.2.3.1 Glazing in doors.
716.2.5 Glazing in fire door assemblies.
716.2.5.1 Size limitations.
716.2.5.1.1 Fire-resistance-rated glazing in door assemblies in fire walls and fire barriers rated greater than 1 hour.
716.2.5.1.2 Fire-protection-rated glazing in door assemblies in fire walls and fire barriers rated greater than 1 hour.
716.2.5.1.2.1 Horizontal exits.
Fire-protection-rated glazing shall be permitted as vision panels in self-closing swinging fire door assemblies serving as horizontal exits in fire walls where limited to 100 square inches (0.065 m2).
716.2.5.1.2.2 Fire barriers.
Fire-protection-rated glazing shall be permitted in fire doors having a 11/2-hour fire protection rating intended for installation in fire barriers, where limited to 100 square inches (0.065 m2).
716.2.5.2 Elevator, stairway and ramp protectives.
716.2.5.3 Glazing in door assemblies in corridors and smoke barriers.
In a 20-minute fire door assembly, the glazing material in the door itself shall have a minimum fire-protection-rated glazing of 20 minutes and shall be exempt from the hose stream test.
716.2.5.4 Fire door frames with transom lights and sidelights.
716.2.6 Fire door hardware and closures.
716.2.6.1 Door closing.
Fire doors shall be latching and self- or automatic-closing in accordance with this section.
Exceptions:
1.Fire doors located in common walls separating sleeping units in Group R-1 shall be permitted without automatic- or self-closing devices.
2.The elevator car doors and the associated hoistway enclosure doors at the floor level designated for recall in accordance with Section 3003.2 shall be permitted to remain open during Phase I emergency recall operation.
716.2.6.2 Latch required.
716.2.6.3 Chute intake door latching.
716.2.6.5 Delayed-action closers.
716.2.6.6 Smoke-activated doors.
Automatic-closing doors installed in the following locations shall be permitted to have hold-open devices. Doors shall automatically close by the actuation of smoke detectors installed in accordance with Section 907.3 or by loss of power to the smoke detector or hold-open device. Doors that are automatic-closing by smoke detection shall not have more than a 10-second delay before the door starts to close after the smoke detector is actuated. Automatic-closing doors that protect openings installed in the following locations shall comply with this section:
1.In walls that separate incidental uses in accordance with Section 509.4.
8.In waste and linen chutes, discharge openings and access and discharge rooms in accordance with Section 713.13. Loading doors installed in waste and linen chutes shall meet the requirements of Sections 716.2.6.1 and 716.2.6.3.
716.2.6.7 Doors in pedestrian ways.
Vertical sliding or vertical rolling steel fire doors in openings through which pedestrians travel shall be heat activated or activated by smoke detectors with alarm verification.
716.2.7 Swinging fire shutters.
Where fire shutters of the swinging type are installed in exterior openings, not less than one row in every three vertical rows shall be arranged to be readily opened from the outside, and shall be identified by distinguishing marks or letters not less than 6 inches (152 mm) high.
716.2.8 Rolling fire shutters.
Where fire shutters of the rolling type are installed, such shutters shall include approved automatic-closing devices.
716.2.9 Labeled protective assemblies.
716.2.9.1 Fire door labeling requirements.
716.2.9.1.1 Light kits, louvers and components.
716.2.9.2 Oversized doors.
Oversized fire doors shall bear an oversized fire door label by an approved agency or shall be provided with a certificate of inspection furnished by an approved testing agency. Where a certificate of inspection is furnished by an approved testing agency, the certificate shall state that the door conforms to the requirements of design, materials and construction, but has not been subjected to the fire test.
716.2.9.3 Smoke and draft control door labeling requirements.
716.2.9.4 Fire door frame labeling requirements.
716.2.9.6 Fire door operator labeling requirements.
716.3 Fire window assemblies.
716.3.1 Testing requirements.
716.3.1.1 Testing under positive pressure.
716.3.1.2 Nonsymmetrical glazing systems.
716.3.2 Performance requirements.
716.3.2.1 Interior fire window assemblies.
716.3.2.1.1 Where 3/4-hour-fire-protection window assemblies permitted.
716.3.2.1.2 Area limitations.
716.3.3 Fire window frames.
716.3.3.1 Window mullions.
716.3.4 Fire-protection-rated glazing.
716.3.5 Labeled protective assemblies.
716.3.5.1 Fire window frames.
716.3.5.2 Labeling requirements.
716.3.6 Installation.
Fire window assemblies shall be installed in accordance with the provisions of this section.
716.3.6.1 Closure.
Fire-protection-rated glazing shall be in the fixed position or be automatic-closing and shall be installed in labeled frames.
716.4 Fire protective curtain assembly.
SECTION 717
DUCTS AND AIR TRANSFER OPENINGS
717.1 General.
The provisions of this section shall govern the protection of duct penetrations and air transfer openings in assemblies required to be protected and duct penetrations in nonfire-resistance-rated floor assemblies.
717.1.1 Ducts and air transfer openings.
717.1.2 Ducts that penetrate fire-resistance-rated assemblies without dampers.
717.2 Installation.
717.2.1 Smoke control system.
717.2.3 Static dampers.
717.3 Damper testing, ratings and actuation.
717.3.1 Damper testing.
Dampers shall be listed and labeled in accordance with the standards in this section.
1.Fire dampers shall comply with the requirements of UL 555.
2.Smoke dampers shall comply with the requirements of UL 555S.
3.Combination fire/smoke dampers shall comply with the requirements of both UL 555 and UL 555S.
4.Ceiling radiation dampers shall comply with the requirements of UL 555C or shall be tested as part of a fire-resistance-rated floor/ceiling or roof/ceiling assembly in accordance with ASTM E119 or UL 263.
5.Corridor dampers shall comply with requirements of both UL 555 and UL 555S. Corridor dampers shall demonstrate acceptable closure performance when subjected to 150 feet per minute (0.76 mps) velocity across the face of the damper during the UL 555 fire exposure test.
717.3.2.1 Fire damper ratings.
TABLE 717.3.2.1
FIRE DAMPER RATING
| TYPE OF PENETRATION | MINIMUM DAMPER RATING (hours) |
| Less than 3-hour fire-resistance-rated assemblies | 1.5 |
| 3-hour or greater fire-resistance-rated assemblies | 3 |
717.3.2.2 Smoke damper ratings.
717.3.3.1 Fire damper actuation.
Primary heat responsive devices used to actuate fire dampers shall meet one of the following requirements:
717.3.3.2 Smoke damper actuation.
The smoke damper shall close upon actuation of a listed smoke detector or detectors installed in accordance with Section 907.3 and one of the following methods, as applicable:
1.Where a smoke damper is installed within a duct, a smoke detector shall be installed inside the duct or outside the duct with sampling tubes protruding into the duct. The detector or tubes within the duct shall be within 5 feet (1524 mm) of the damper. Air outlets and inlets shall not be located between the detector or tubes and the damper. The detector shall be listed for the air velocity, temperature and humidity anticipated at the point where it is installed. Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate.
2.Where a smoke damper is installed above smoke barrier doors in a smoke barrier, a spot-type detector shall be installed on either side of the smoke barrier door opening. The detector shall be listed for releasing service if used for direct interface with the damper.
3.Where a smoke damper is installed within an air transfer opening in a wall, a spot-type detector shall be installed within 5 feet (1524 mm) horizontally of the damper. The detector shall be listed for releasing service if used for direct interface with the damper.
4.Where a smoke damper is installed in a corridor wall or ceiling, the damper shall be permitted to be controlled by a smoke detection system installed in the corridor.
5.Where a smoke detection system is installed in all areas served by the duct in which the damper will be located, the smoke dampers shall be permitted to be controlled by the smoke detection system.
717.3.3.3 Combination fire/smoke damper actuation.
717.3.3.4 Ceiling radiation damper actuation.
717.4 Access and identification.
717.4.1 Access.
717.4.1.1 Access openings.
717.4.2 Identification.
717.5 Where required.
717.5.1.1 Horizontal exits.
717.5.2 Fire barriers.
Ducts and air transfer openings of fire barriers shall be protected with listed fire dampers installed in accordance with their listing. Ducts and air transfer openings shall not penetrate enclosures for interior exit stairways and ramps and exit passageways, except as permitted by Sections 1023.5 and 1024.6, respectively.
Exceptions: Fire dampers are not required at penetrations of fire barriers where any of the following apply:
1.Penetrations are tested in accordance with ASTM E119 or UL 263 as part of the fire-resistance-rated assembly.
2.Ducts are used as part of an approved smoke control system in accordance with Section 909 and where the use of a fire damper would interfere with the operation of a smoke control system.
3.Such walls are penetrated by fully ducted HVAC systems, have a required fire-resistance rating of 1 hour or less, are in areas of other than Group H and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a fully ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure’s HVAC system. Such a duct system shall be constructed of sheet steel not less than No. 26 gage thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals. Nonmetal flexible air connectors shall be permitted in the following locations:
3.1.At the duct connection to the air handling unit or equipment located within the mechanical room in accordance with Section 603.9 of the International Mechanical Code.
3.2.From an overhead metal duct to a ceiling diffuser within the same room in accordance with Section 603.6.2 of the International Mechanical Code.
717.5.2.1 Horizontal exits.
717.5.3 Shaft enclosures.
Shaft enclosures that are permitted to be penetrated by ducts and air transfer openings shall be protected with listed fire and smoke dampers installed in accordance with their listing.
Exceptions:
1.Fire dampers are not required at penetrations of shafts where any of the following criteria are met:
1.1.Steel exhaust subducts having a wall thickness of not less than 0.0187 inch (0.4712 mm) are extended not less than 22 inches (559 mm) vertically in exhaust shafts, and an exhaust fan is installed at the upper terminus of the shaft that is powered continuously in accordance with Section 909.11, so as to maintain a continuous upward airflow to the outdoors.
1.2.Penetrations are tested in accordance with ASTM E119 or UL 263 as part of the fire-resistance-rated assembly.
1.3.Ducts are used as part of an approved smoke control system designed and installed in accordance with Section 909 and where the fire damper will interfere with the operation of the smoke control system.
1.4.The penetrations are in parking garage exhaust or supply shafts that are separated from other building shafts by not less than 2-hour fire-resistance-rated construction.
2.In Group B and R occupancies equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1, smoke dampers are not required at penetrations ofshaftswhere all of the following criteria are met:
2.1.Kitchen, clothes dryer, bathroom and toilet room exhaust openings are installed with steel exhaust subducts, having a wall thickness of not less than 0.0187 inch (0.4712 mm).
2.2.The subducts extend not less than 22 inches (559 mm) vertically.
2.3.An exhaust fan is installed at the upper terminus of the shaft that is powered continuously in accordance with the provisions of Section 909.11, so as to maintain a continuous upward airflow to the outdoors.
3.Smoke dampers are not required at penetration of exhaust or supply shafts in parking garages that are separated from other building shafts by not less than 2-hour fire-resistance-rated construction.
4.Smoke dampers are not required at penetrations of shafts where ducts are used as part of an approved mechanical smoke control system designed in accordance with Section 909 and where the smoke damper will interfere with the operation of the smoke control system.
5.Fire dampers and combination fire/smoke dampers are not required in kitchen and clothes dryer exhaust systems where dampers are prohibited by the International Mechanical Code.
717.5.3.1 Continuous upward airflow.
717.5.4 Fire partitions.
Ducts and air transfer openings that penetrate fire partitions shall be protected with listed fire dampers installed in accordance with their listing.
Exceptions: In occupancies other than Group H, fire dampers are not required where any of the following apply:
1.Corridor walls in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2 and the duct is protected as a through penetration in accordance with Section 714.
2.Tenant partitions in covered and open mall buildings where the walls are not required by provisions elsewhere in the code to extend to the underside of the floor or roof sheathing, slab or deck above.
3.The duct system is constructed of approved materials in accordance with the International Mechanical Code and the duct penetrating the wall complies with all of the following requirements:
3.1.The duct shall not exceed 100 square inches (0.06 m2).
3.2.The duct shall be constructed of steel not less than 0.0217 inch (0.55 mm) in thickness.
3.3.The duct shall not have openings that communicate the corridor with adjacent spaces or rooms.
3.4.The duct shall be installed above a ceiling.
3.5.The duct shall not terminate at a wall register in the fire-resistance-rated wall.
3.6.A minimum 12-inch-long (305 mm) by 0.060-inch-thick (1.52 mm) steel sleeve shall be centered in each duct opening. The sleeve shall be secured to both sides of the wall and all four sides of the sleeve with minimum 11/2-inch by 11/2-inch by 0.060-inch (38 mm by 38 mm by 1.52 mm) steel retaining angles. The retaining angles shall be secured to the sleeve and the wall with No. 10 (M5) screws. The annular space between the steel sleeve and the wall opening shall be filled with mineral wool batting on all sides.
4.Such walls are penetrated by ducted HVAC systems, have a required fire-resistance rating of 1 hour or less, and are in buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 or 903.3.1.2. For the purposes of this exception, a ducted HVAC system shall be a duct system for conveying supply, return or exhaust air as part of the structure’s HVAC system. Such a duct system shall be constructed of sheet steel not less than No. 26 gage thickness and shall be continuous from the air-handling appliance or equipment to the air outlet and inlet terminals.
717.5.4.1 Corridors.
Duct and air transfer openings that penetrate corridors shall be protected with dampers as follows:
1.A corridor damper shall be provided where corridor ceilings, constructed as required for the corridor walls as permitted in Section 708.4, Exception 3, are penetrated.
2.A ceiling radiation damper shall be provided where the ceiling membrane of a fire-resistance-rated floor-ceiling or roof-ceiling assembly, constructed as permitted in Section 708.4, Exception 2, is penetrated.
3.A listed smoke damper designed to resist the passage of smoke shall be provided at each point a duct or air transfer opening penetrates a corridor enclosure required to have smoke and draft control doors in accordance with Section 716.2.2.1.
Exceptions:
1.Smoke dampers are not required where the building is equipped throughout with an approved smoke control system in accordance with Section 909, and smoke dampers are not necessary for the operation and control of the system.
2.Smoke dampers are not required in corridor penetrations where the duct is constructed of steel not less than 0.019 inch (0.48 mm) in thickness and there are no openings serving the corridor.
717.5.5 Smoke barriers.
A listed smoke damper designed to resist the passage of smoke shall be provided at each point a duct or air transfer opening penetrates a smoke barrier. Smoke dampers and smoke damper actuation methods shall comply with Section 717.3.3.2.
Exceptions:
1.Smoke dampers are not required where the openings in ducts are limited to a single smoke compartment and the ducts are constructed of steel.
2.Smoke dampers are not required in smoke barriers required by Section 407.5 for Group I-2, Condition 2—where the HVAC system is fully ducted in accordance with Section 603 of the International Mechanical Code and where buildings are equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1 and equipped with quick-response sprinklers in accordance with Section 903.3.2.
717.6 Horizontal assemblies.
717.6.1 Through penetrations.
In occupancies other than Groups I-2 and I-3, a duct constructed of approved materials in accordance with the International Mechanical Code that penetrates a fire-resistance-rated floor/ceiling assembly that connects not more than two stories is permitted without shaft enclosure protection, provided that a listed fire damper is installed at the floor line or the duct is protected in accordance with Section 714.5. For air transfer openings, see Section 712.1.9.
Exception: A duct is permitted to penetrate three floors or less without a fire damper at each floor, provided that such duct meets all of the following requirements:
1.The duct shall be contained and located within the cavity of a wall and shall be constructed of steel having a minimum wall thickness of 0.0187 inches (0.4712 mm) (No. 26 gage).
2.The duct shall open into only one dwelling unitor sleeping unit and the duct system shall be continuous from the unit to the exterior of the building.
3.The duct shall not exceed 4-inch (102 mm) nominal diameter and the total area of such ducts shall not exceed 100 square inches (0.065 m2) in any 100 square feet (9.3 m2) of floor area.
4.The annular space around the duct is protected with materials that prevent the passage of flame and hot gases sufficient to ignite cotton waste where subjected to ASTM E119 or UL 263 time-temperature conditions under a minimum positive pressure differential of 0.01 inch (2.49 Pa) of water at the location of the penetration for the time period equivalent to the fire-resistance rating of the construction penetrated.
5.Grille openings located in a ceiling of a fire-resistance-rated floor/ceiling or roof/ceiling assembly shall be protected with a listed ceiling radiation damper installed in accordance with Section 717.6.2.1.
717.6.2 Membrane penetrations.
Ducts and air transfer openings constructed of approved materials in accordance with the International Mechanical Code that penetrate the ceiling membrane of a fire-resistance-rated floor/ceiling or roof/ceiling assembly shall be protected with one of the following:
2.A listed ceiling radiation damper installed at the ceiling line where a duct penetrates the ceiling of a fire-resistance-rated floor/ceiling or roof/ceiling assembly.
Exceptions:
1.A fire-resistance-rated assembly tested in accordance with ASTM E119 or UL 263 showing that ceiling radiation dampers are not required in order to maintain the fire-resistance rating of the assembly.
2.Where exhaust duct or outdoor air duct penetrations protected in accordance with Section 714.5.2 are located within the cavity of a wall and do not pass through another dwelling unit or tenant space.
3.Where duct and air transfer openings are protected with a duct outlet penetration system tested as part of a fire-resistance-rated assembly in accordance with ASTM E119 or UL 263.
3.A listed ceiling radiation damper installed at the ceiling line where a diffuser with no duct attached penetrates the ceiling of a fire-resistance-rated floor/ceiling or roof/ceiling assembly.
Exceptions:
1.A fire-resistance-rated assembly tested in accordance with ASTM E119 or UL 263 showing that ceiling radiation dampers are not required in order to maintain the fire-resistance rating of the assembly.
2.Where duct and air transfer openings are protected with a duct outlet penetration system tested as part of a fire-resistance-rated assembly in accordance with ASTM E119 or UL 263.
717.6.2.1 Ceiling radiation dampers testing and installation.
717.6.2.1.1 Dynamic systems.
717.6.2.1.2 Static systems.
Exceptions:
1.Where a static ceiling radiation damper is installed at the opening of a duct, a smoke detector shall be installed inside the duct or outside the duct with sampling tubes protruding into the duct. The detector or tubes in the duct shall be within 5 feet (1524 mm) of the damper. Air outlets and inlets shall not be located between the detector or tubes and the damper. The detector shall be listed for the air velocity, temperature and humidity anticipated at the point where it is installed. Other than in mechanical smoke control systems, dampers shall be closed upon fan shutdown where local smoke detectors require a minimum velocity to operate.
2.Where a static ceiling radiation damper is installed in a ceiling, the ceiling radiation damper shall be permitted to be controlled by a smoke detection system installed in the same room or area as the ceiling radiation damper.
3.A static ceiling radiation damper shall be permitted to be installed in a room where an occupant sensor is provided within the room that will shut down the system.
717.6.3 Nonfire-resistance-rated floor assemblies.
Duct systems constructed of approved materials in accordance with the International Mechanical Code that penetrate nonfire-resistance-rated floor assemblies shall be protected by any of the following methods:
2.The duct connects not more than two stories, and the annular space around the penetrating duct is protected with an approved noncombustible material that resists the free passage of flame and the products of combustion.
3.In floor assemblies composed of noncombustible materials, a shaft shall not be required where the duct connects not more than three stories, the annular space around the penetrating duct is protected with an approved noncombustible material that resists the free passage of flame and the products of combustion and a fire damper is installed at each floor line.
Exception: Fire dampers are not required in ducts within individual residential dwelling units.
717.7 Flexible ducts and air connectors.
SECTION 718
CONCEALED SPACES
718.1 General.
718.2 Fireblocking.
718.2.1 Fireblocking materials.
Fireblocking shall consist of the following materials:
1.Two-inch (51 mm) nominal lumber.
2.Two thicknesses of 1-inch (25 mm) nominal lumber with broken lap joints.
3.One thickness of 0.719-inch (18.3 mm) wood structural panelswith joints backed by 0.719-inch (18.3 mm) wood structural panels.
4.One thickness of 0.75-inch (19.1 mm) particleboardwith joints backed by 0.75-inch (19 mm) particleboard.
5.One-half-inch (12.7 mm)gypsum board.
6.One-fourth-inch (6.4 mm) cement-based millboard.
7.Batts or blankets of mineral wool, mineral fiber or other approved materials installed in such a manner as to be securely retained in place.
8.Cellulose insulation tested in the form and manner intended for use to demonstrate its ability to remain in place and to retard the spread of fire and hot gases.
718.2.1.1 Batts or blankets of mineral wool or mineral fiber.
718.2.1.2 Unfaced fiberglass.
Unfaced fiberglass batt insulation used as fireblocking shall fill the entire cross section of the wall cavity to a minimum height of 16 inches (406 mm) measured vertically. Where piping, conduit or similar obstructions are encountered, the insulation shall be packed tightly around the obstruction.
718.2.1.3 Loose-fill insulation material.
Loose-fill insulation material, insulating foam sealants and caulk materials shall not be used as a fireblock unless specifically tested in the form and manner intended for use to demonstrate its ability to remain in place and to retard the spread of fire and hot gases.
718.2.1.4 Fireblocking integrity.
The integrity of fireblocks shall be maintained.
718.2.1.5 Double stud walls.
Batts or blankets of mineral or glass fiber or other approved nonrigid materials shall be allowed as fireblocking in walls constructed using parallel rows of studs or staggered studs.
718.2.2 Concealed wall spaces.
Fireblocking shall be provided in concealed spaces of stud walls and partitions, including furred spaces, and parallel rows of studs or staggered studs, as follows:
1.Vertically at the ceiling and floor levels.
2.Horizontally at intervals not exceeding 10 feet (3048 mm).
718.2.3 Connections between horizontal and vertical spaces.
Fireblocking shall be provided at interconnections between concealed vertical stud wall or partition spaces and concealed horizontal spaces created by an assembly of floor joists or trusses, and between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings, cove ceilings and similar locations.
718.2.5 Ceiling and floor openings.
718.2.6 Exterior wall coverings.
Fireblocking shall be installed within concealed spaces of exterior wall coverings and other exterior architectural elements where permitted to be of combustible construction as specified in Section 1405 or where erected with combustible frames. Fireblocking shall be installed at maximum intervals of 20 feet (6096 mm) in either dimension so that there will be no concealed space exceeding 100 square feet (9.3 m2) between fireblocking. Where wood furring strips are used, they shall be of approved wood of natural decay resistance or preservative-treated wood. If noncontinuous, such elements shall have closed ends, with not less than 4 inches (102 mm) of separation between sections.
Exceptions:
1.Fireblocking ofcornices is not required in single-family dwellings. Fireblocking of cornices of a two-family dwelling is required only at the line of dwelling unit separation.
2.Fireblocking shall not be required where the exterior wall covering is installed on noncombustible framing and the face of the exterior wallcovering exposed to the concealed space is covered by one of the following materials:
2.1.Aluminum having a minimum thickness of 0.019 inch (0.5 mm).
2.2.Corrosion-resistant steel having a base metal thickness not less than 0.016 inch (0.4 mm) at any point.
2.3.Other approved noncombustible materials.
3.Fireblocking shall not be required where the exterior wall covering has been tested in accordance with, and complies with the acceptance criteria of, NFPA 285. Theexterior wallcovering shall be installed as tested in accordance with NFPA 285.
718.2.7 Concealed sleeper spaces.
Where wood sleepers are used for laying wood flooring on masonry or concrete fire-resistance-rated floors, the space between the floor slab and the underside of the wood flooring shall be filled with an approved material to resist the free passage of flame and products of combustion or fireblocked in such a manner that open spaces under the flooring shall not exceed 100 square feet (9.3 m2) in area and such space shall be filled solidly under permanent partitions so that communication under the flooring between adjoining rooms shall not occur.
Exceptions:
1.Fireblocking is not required for slab-on-grade floors in gymnasiums.
2.Fireblocking is required only at the juncture of each alternate lane and at the ends of each lane in a bowling facility.
718.3 Draftstopping in floors.
718.3.1 Draftstopping materials.
718.4 Draftstopping in attics.
Draftstopping shall be installed to subdivide attic spaces where required by Section 708.4.2. In other than Group R, draftstopping shall be installed to subdivide combustible attic spaces and combustible concealed roof spaces such that any horizontal area does not exceed 3,000 square feet (279 m2). Ventilation of concealed roof spaces shall be maintained in accordance with Section 1202.2.1.
718.4.1.1 Openings.
718.5 Combustible materials in concealed spaces in Type I or II construction.
Combustible materials shall not be permitted in concealed spaces of buildings of Type I or II construction.
Exceptions:
2.Combustible materials exposed within plenums complying with Section 602 of the International Mechanical Code.
3.Class A interior finish materials classified in accordance with Section 803.
4.Combustible piping within partitions or shaft enclosures installed in accordance with the provisions of this code.
5.Combustible piping within concealed ceiling spaces installed in accordance with the International Mechanical Code and the International Plumbing Code.
6.Combustible insulation and covering on pipe and tubing, installed in concealed spaces other than plenums, complying with Section 720.7.
SECTION 719
FIRE-RESISTANCE REQUIREMENTS FOR PLASTER
719.1 Thickness of plaster.
The minimum thickness of gypsum plaster or Portland cement plaster used in a fire-resistance-rated system shall be determined by the prescribed fire tests. The plaster thickness shall be measured from the face of the lath where applied to gypsum lath or metal lath.
719.2 Plaster equivalents.
For fire-resistance purposes, 1/2 inch (12.7 mm) of unsanded gypsum plaster shall be deemed equivalent to 3/4 inch (19.1 mm) of one-to-three gypsum sand plaster or 1 inch (25 mm) of Portland cement sand plaster.
719.3 Noncombustible furring.
719.4 Double reinforcement.
Plaster protection more than 1 inch (25 mm) in thickness shall be reinforced with an additional layer of approved lath embedded not less than 3/4 inch (19.1 mm) from the outer surface and fixed securely in place.
719.5 Plaster alternatives for concrete.
SECTION 720
THERMAL- AND SOUND-INSULATING MATERIALS
720.1 General.
Insulating materials shall comply with the requirements of this section. Where a flame spread indexor a smoke-developed index is specified in this section, such index shall be determined in accordance with ASTM E84 or UL 723. Any material that is subject to an increase in flame spread indexor smoke-developed index beyond the limits herein established through the effects of age, moisture or other atmospheric conditions shall not be permitted. Insulating materials, when tested in accordance with the requirements of this section, shall include facings, when used, such as vapor retarders, vapor permeable membranes and similar coverings, and all layers of single and multilayer reflective foil insulation and similar materials.
720.2 Concealed installation.
Insulating materials, where concealed as installed in buildings of any type of construction, shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 450.
720.2.1 Facings.
Where such materials are installed in concealed spaces in buildings of Type III, IV or V construction, the flame spread and smoke-developed limitations do not apply to facings, coverings, and layers of reflective foil insulation that are installed behind and in substantial contact with the unexposed surface of the ceiling, wall or floor finish.
720.3 Exposed installation.
Insulating materials, where exposed as installed in buildings of any type of construction, shall have a flame spread index of not more than 25 and a smoke-developed index of not more than 450.
720.6 Cellulosic fiber loose-fill insulation and self-supported spray-applied cellulosic insulation.
720.7 Insulation and covering on pipe and tubing.
SECTION 721
PRESCRIPTIVE FIRE RESISTANCE
721.1 General.
TABLE 721.1(1)
MINIMUM PROTECTION OF STRUCTURAL PARTS BASED ON TIME PERIODS FOR VARIOUS NONCOMBUSTIBLE INSULATING MATERIALSm
| STRUCTURAL PARTS TO BE PROTECTED | ITEM NUMBER | INSULATING MATERIAL USED | MINIMUM THICKNESS OF INSULATING MATERIAL FOR THE FOLLOWING FIRE-RESISTANCE PERIODS (inches) | |||
| 4 hours | 3 hours | 2 hours | 1 hour | |||
| 1. Steel columns and all of primary trusses | 1-1.1 | Carbonate, lightweight and sand-lightweight aggregate concrete, members 6" × 6" or greater (not including sandstone, granite and siliceous gravel).a | 21/2 | 2 | 11/2 | 1 |
| 1-1.2 | Carbonate, lightweight and sand-lightweight aggregate concrete, members 8" × 8" or greater (not including sandstone, granite and siliceous gravel).a | 2 | 11/2 | 1 | 1 | |
| 1-1.3 | Carbonate, lightweight and sand-lightweight aggregate concrete, members 12" × 12" or greater (not including sandstone, granite and siliceous gravel).a | 11/2 | 1 | 1 | 1 | |
| 1-1.4 | Siliceous aggregate concrete and concrete excluded in Item 1-1.1, members 6" × 6" or greater.a | 3 | 2 | 11/2 | 1 | |
| 1-1.5 | Siliceous aggregate concrete and concrete excluded in Item 1-1.1, members 8" × 8" or greater.a | 21/2 | 2 | 1 | 1 | |
| 1-1.6 | Siliceous aggregate concrete and concrete excluded in Item 1-1.1, members 12" × 12" or greater.a | 2 | 1 | 1 | 1 | |
| 1-2.1 | Clay or shale brick with brick and mortar fill.a | 33/4 | — | — | 21/4 | |
| 1-3.1 | 4" hollow clay tile in two 2" layers; 1/2" mortar between tile and column; 3/8" metal mesh 0.046" wire diameter in horizontal joints; tile fill.a | 4 | — | — | — | |
| 1-3.2 | 2" hollow clay tile; 3/4" mortar between tile and column; 3/8" metal mesh 0.046" wire diameter in horizontal joints; limestone concrete filla; plastered with 3/4" gypsum plaster. | 3 | — | — | — | |
| 1-3.3 | 2" hollow clay tile with outside wire ties 0.08" diameter at each course of tile or 3/8" metal mesh 0.046" diameter wire in horizontal joints; limestone or trap-rock concrete filla extending 1" outside column on all sides. | — | — | 3 | — | |
| 1-3.4 | 2" hollow clay tile with outside wire ties 0.08" diameter at each course of tile with or without concrete fill; 3/4" mortar between tile and column. | — | — | — | 2 | |
| 1-4.1 | Cement plaster over metal lath wire tied to 3/4" cold-rolled vertical channels with 0.049" (No. 18 B.W. gage) wire ties spaced 3" to 6" on center. Plaster mixed 1:21/2 by volume, cement to sand. | — | — | 21/2b | 7/8 | |
| 1-5.1 | Vermiculite concrete, 1:4 mix by volume over paper-backed wire fabric lath wrapped directly around column with additional 2" × 2" 0.065"/0.065" (No. 16/16 B.W. gage) wire fabric placed 3/4" from outer concrete surface. Wire fabric tied with 0.049" (No. 18B.W. gage) wire spaced 6" on center for inner layer and 2" on center for outer layer. | 2 | — | — | — | |
| 1-6.1 | Perlite or vermiculite gypsum plaster over metal lath wrapped around column and furred 11/4" from column flanges. Sheets lapped at ends and tied at 6" intervals with 0.049" (No. 18 B.W. gage) tie wire. Plaster pushed through to flanges. | 11/2 | 1 | — | — | |
| 1-6.2 | Perlite or vermiculite gypsum plaster over self-furring metal lath wrapped directly around column, lapped 1" and tied at 6" intervals with 0.049" (No. 18 B.W. gage) wire. | 13/4 | 13/8 | 1 | — | |
| 1-6.3 | Perlite or vermiculite gypsum plaster on metal lath applied to 3/4" cold-rolled channels spaced 24" apart vertically and wrapped flatwise around column. | 11/2 | — | — | — | |
| 1-6.4 | Perlite or vermiculite gypsum plaster over two layers of 1/2" plain full-length gypsum lath applied tight to column flanges. Lath wrapped with 1" hexagonal mesh of No. 20-gage wire and tied with doubled 0.035" diameter (No. 18 B.W. gage) wire ties spaced 23" on center. For three-coat work, the plaster mix for the second coat shall not exceed 100 pounds of gypsum to 21/2 cubic feet of aggregate for the 3-hour system. | 21/2 | 2 | — | — | |
| 1-6.5 | Perlite or vermiculite gypsum plaster over one layer of 1/2" plain full-length gypsum lath applied tight to column flanges. Lath tied with doubled 0.049" (No. 18 B.W. gage) wire ties spaced 23" on center and scratch coat wrapped with 1" hexagonal mesh 0.035" (No. 20 B.W. gage) wire fabric. For three-coat work, the plaster mix for the second coat shall not exceed 100 pounds of gypsum to 21/2 cubic feet of aggregate. | — | 2 | — | — | |
| 1-7.1 | Multiple layers of 1/2" gypsum wallboardc adhesivelyd secured to column flanges and successive layers. Wallboard applied without horizontal joints. Corner edges of each layer staggered. Wallboard layer below outer layer secured to column with doubled 0.049" (No. 18 B.W. gage) steel wire ties spaced 15" on center. Exposed corners taped and treated. | — | — | 2 | 1 | |
| 1-7.2 | Three layers of 5/8" Type X gypsum wallboard.c First and second layer held in place by 1/8" diameter by 13/8" long ring shank nails with 5/16" diameter heads spaced 24" on center at corners. Middle layer also secured with metal straps at mid-height and 18" from each end, and by metal corner bead at each corner held by the metal straps. Third layer attached to corner bead with 1" long gypsum wallboard screws spaced 12" on center. | — | — | 17/8 | — | |
| 1-7.3 | Three layers of 5/8" Type X gypsum wallboard,c each layer screw attached to 15/8" steel studs 0.018" thick (No. 25 carbon sheet steel gage) at each corner of column. Middle layer also secured with 0.049" (No. 18 B.W. gage) double-strand steel wire ties, 24" on center. Screws are No. 6 by 1" spaced 24" on center for inner layer, No. 6 by 15/8" spaced 12" on center for middle layer and No. 8 by 21/4" spaced 12" on center for outer layer. | — | 17/8 | — | — | |
| 1-8.1 | Wood-fibered gypsum plaster mixed 1:1 by weight gypsum-to-sand aggregate applied over metal lath. Lath lapped 1" and tied 6" on center at all end, edges and spacers with 0.049" (No. 18 B.W. gage) steel tie wires. Lath applied over 1/2" spacers made of 3/4" furring channel with 2" legs bent around each corner. Spacers located 1" from top and bottom of member and not greater than 40" on center and wire tied with a single strand of 0.049" (No. 18 B.W. gage) steel tie wires. Corner bead tied to the lath at 6" on center along each corner to provide plaster thickness. | — | — | 15/8 | — | |
| 1-9.1 | Minimum W8x35 wide flange steel column (w/d ≥ 0.75) with each web cavity filled even with the flange tip with normal weight carbonate or siliceous aggregate concrete (3,000 psi minimum compressive strength with 145 pcf ± 3 pcf unit weight). Reinforce the concrete in each web cavity with a minimum No. 4 deformed reinforcing bar installed vertically and centered in the cavity, and secured to the column web with a minimum No. 2 horizontal deformed reinforcing bar welded to the web every 18" on center vertically. As an alternative to the No. 4 rebar, 3/4" diameter by 3" long headed studs, spaced at 12" on center vertically, shall be welded on each side of the web mid-way between the column flanges. | — | — | — | See Note n | |
| 2. Webs or flanges of steel beams and girders | 2-1.1 | Carbonate, lightweight and sand-lightweight aggregate concrete (not including sandstone, granite and siliceous gravel) with 3" or finer metal mesh placed 1" from the finished surface anchored to the top flange and providing not less than 0.025 square inch of steel area per foot in each direction. | 2 | 11/2 | 1 | 1 |
| 2-1.2 | Siliceous aggregate concrete and concrete excluded in Item 2-1.1 with 3" or finer metal mesh placed 1" from the finished surface anchored to the top flange and providing not less than 0.025 square inch of steel area per foot in each direction. | 21/2 | 2 | 11/2 | 1 | |
| 2-2.1 | Cement plaster on metal lath attached to 3/4" cold-rolled channels with 0.04" (No. 18 B.W. gage) wire ties spaced 3" to 6" on center. Plaster mixed 1:21/2 by volume, cement to sand. | — | — | 21/2b | 7/8 | |
| 2-3.1 | Vermiculite gypsum plaster on a metal lath cage, wire tied to 0.165" diameter (No. 8 B.W. gage) steel wire hangers wrapped around beam and spaced 16" on center. Metal lath ties spaced approximately 5" on center at cage sides and bottom. | — | 7/8 | — | — | |
| 2-4.1 | Two layers of 5/8" Type X gypsum wallboardc are attached to U-shaped brackets spaced 24" on center. 0.018" thick (No. 25 carbon sheet steel gage) 15/8" deep by 1" galvanized steel runner channels are first installed parallel to and on each side of the top beam flange to provide a 1/2" clearance to the flange. The channel runners are attached to steel deck or concrete floor construction with approved fasteners spaced 12" on center. U-shaped brackets are formed from members identical to the channel runners. At the bent portion of the U-shaped bracket, the flanges of the channel are cut out so that 15/8"-deep corner channels can be inserted without attachment parallel to each side of the lower flange. As an alternative, 0.021" thick (No. 24 carbon sheet steel gage) 1" × 2" runner and corner angles shall be used in lieu of channels, and the web cutouts in the U-shaped brackets shall not be required. Each angle is attached to the bracket with 1/2"-long No. 8 self-drilling screws. The vertical legs of the U-shaped bracket are attached to the runners with one 1/2"-long No. 8 self-drilling screw. The completed steel framing provides a 21/8" and 11/2" space between the inner layer of wallboard and the sides and bottom of the steel beam, respectively. The inner layer of wallboard is attached to the top runners and bottom corner channels or corner angles with 11/4"-long No. 6 self-drilling screws spaced 16" on center. The outer layer of wallboard is applied with 13/4"-long No. 6 self-drilling screws spaced 8" on center. The bottom corners are reinforced with metal corner beads. | — | — | 11/4 | — | |
| 2-4.2 | Three layers of 5/8" Type X gypsum wallboardc attached to a steel suspension system as described immediately above utilizing the 0.018" thick (No. 25 carbon sheet steel gage) 1" × 2" lower corner angles. The framing is located so that a 21/8" and 2" space is provided between the inner layer of wallboard and the sides and bottom of the beam, respectively. The first two layers of wallboard are attached as described immediately above. A layer of 0.035" thick (No. 20 B.W. gage) 1" hexagonal galvanized wire mesh is applied under the soffit of the middle layer and up the sides approximately 2". The mesh is held in position with the No. 6 15/8"-long screws installed in the vertical leg of the bottom corner angles. The outer layer of wallboard is attached with No. 6 21/4"-long screws spaced 8" on center. One screw is installed at the mid-depth of the bracket in each layer. Bottom corners are finished as described above. | — | 17/8 | — | — | |
| 3. Bonded pretensioned reinforcement in prestressed concretee | 3-1.1 | Carbonate, lightweight, sand-lightweight and siliceousf aggregate concrete | ||||
Beams or girders | 4g | 3g | 21/2 | 11/2 | ||
Solidh | 2 | 11/2 | 1 | |||
| 4. Bonded or unbonded post-tensioned tendons in prestressed concretee, i | 4-1.1 | Carbonate, lightweight, sand-lightweight and siliceousf aggregate concrete Unrestrained members: | ||||
Solid slabsh | — | 2 | 11/2 | — | ||
Beams and girdersj | ||||||
8" wide | 41/2 | 21/2 | 13/4 | |||
greater than 12" wide | 3 | 21/2 | 2 | 11/2 | ||
| 4-1.2 | Carbonate, lightweight, sand-lightweight and siliceous aggregate Restrained members:k | |||||
Solid slabsh | 11/4 | 1 | 3/4 | — | ||
Beams and girdersj | ||||||
8" wide | 21/2 | 2 | 13/4 | — | ||
greater than 12" wide | 2 | 13/4 | 11/2 | — | ||
| 5. Reinforcing steel in reinforced concrete columns, beams girders and trusses | 5-1.1 | Carbonate, lightweight and sand-lightweight aggregate concrete, members 12" or larger, square or round. (Size limit does not apply to beams and girders monolithic with floors.) | 11/2 | 11/2 | 11/2 | 11/2 |
| Siliceous aggregate concrete, members 12" or larger, square or round. (Size limit does not apply to beams and girders monolithic with floors.) | 2 | 11/2 | 11/2 | 11/2 | ||
| 6. Reinforcing steel in reinforced concrete joists1 | 6-1.1 | Carbonate, lightweight and sand-lightweight aggregate concrete | 11/4 | 11/4 | 1 | 3/4 |
| 6-1.2 | Siliceous aggregate concrete | 13/4 | 11/2 | 1 | 3/4 | |
| 7. Reinforcing and tie rods in floor and roof slabs1 | 7-1.1 | Carbonate, lightweight and sand-lightweight aggregate concrete | 1 | 1 | 3/4 | 3/4 |
| 7-1.2 | Siliceous aggregate concrete | 11/4 | 1 | 1 | 3/4 | |
For SI: 1 inch = 25.4 mm, 1 square inch = 645.2 mm2, 1 cubic foot = 0.0283 m3, 1 pound per cubic foot = 16.02 kg/m3.
a.Reentrant parts of protected members to be filled solidly.
b.Two layers of equal thickness with a 3/4-inch airspace between.
c.For all of the construction with gypsum wallboard described in Table 721.1(1), gypsum base for veneer plaster of the same size, thickness and core type shall be permitted to be substituted for gypsum wallboard, provided that attachment is identical to that specified for the wallboard and the joints on the face layer are reinforced, and the entire surface is covered with not less than 1/16-inch gypsum veneer plaster.
e.Where lightweight or sand-lightweight concrete having an oven-dry weight of 110 pounds per cubic foot or less is used, the tabulated minimum cover shall be permitted to be reduced 25 percent, except that the reduced cover shall be not less than 3/4 inch in slabs or 11/2 inches in beams or girders.
f.For solid slabs of siliceous aggregate concrete, increase tendon cover 20 percent.
g.Adequate provisions against spalling shall be provided by U-shaped or hooped stirrups spaced not to exceed the depth of the member with a clear cover of 1 inch.
h.Prestressed slabs shall have a thickness not less than that required in Table 721.1(3) for the respective fire-resistance time period.
i.Fire coverage and end anchorages shall be as follows: Cover to the prestressing steel at the anchor shall be 1/2 inch greater than that required away from the anchor. Minimum cover to steel-bearing plate shall be 1 inch in beams and 3/4 inch in slabs.
j.For beam widths between 8 inches and 12 inches, cover thickness shall be permitted to be determined by interpolation.
k.Interior spans of continuous slabs, beams and girders shall be permitted to be considered restrained.
l.For use with concrete slabs having a comparable fire endurance where members are framed into the structure in such a manner as to provide equivalent performance to that of monolithic concrete construction.
m.Generic fire-resistance ratings (those not designated as PROPRIETARY* in the listing) in GA 600 shall be accepted as if herein specified.
n.Additional insulating material is not required on the exposed outside face of the column flange to achieve a 1-hour fire-resistance rating.
TABLE 721.1(2)
RATED FIRE-RESISTANCE PERIODS FOR VARIOUS WALLS AND PARTITIONS a, o, p
For SI: 1 inch = 25.4 mm, 1 square inch = 645.2 mm2, 1 cubic foot = 0.0283 m3.
a.Staples with equivalent holding power and penetration shall be permitted to be used as alternate fasteners to nails for attachment to wood framing.
b.Thickness shown for brick and clay tile is nominal thicknesses unless plastered, in which case thicknesses are net. Thickness shown for concrete masonry and clay masonry is equivalent thickness defined in Section 722.3.1 for concrete masonry and Section 722.4.1.1 for clay masonry. Where all cells are solid grouted or filled with silicone-treated perlite loose-fill insulation; vermiculite loose-fill insulation; or expanded clay, shale or slate lightweight aggregate, the equivalent thickness shall be the thickness of the block or brick using specified dimensions as defined in Chapter 21. Equivalent thickness shall include the thickness of applied plaster and lath or gypsum wallboard, where specified.
c.For units in which the net cross-sectional area of cored brick in any plane parallel to the surface containing the cores is not less than 75 percent of the gross cross-sectional area measured in the same plane.
d.Shall be used for nonbearing purposes only.
e.For all of the construction with gypsum wallboard described in this table, gypsum base for veneer plaster of the same size, thickness and core type shall be permitted to be substituted for gypsum wallboard, provided that attachment is identical to that specified for the wallboard, and the joints on the face layer are reinforced and the entire surface is covered with not less than 1/16-inch gypsum veneer plaster.
f.The fire-resistance time period for concrete masonry units meeting the equivalent thicknesses required for a 2-hour fire-resistance rating in Item 3, and having a thickness of not less than 75/8 inches is 4 hours where cores that are not grouted are filled with silicone-treated perlite loose-fill insulation; vermiculite loose-fill insulation; or expanded clay, shale or slate lightweight aggregate, sand or slag having a maximum particle size of 3/8 inch.
g.The fire-resistance rating of concrete masonry units composed of a combination of aggregate types or where plaster is applied directly to the concrete masonry shall be determined in accordance with ACI 216.1/TMS 0216. Lightweight aggregates shall have a maximum combined density of 65 pounds per cubic foot.
h.See Note b. The equivalent thickness shall be permitted to include the thickness of cement plaster or 1.5 times the thickness of gypsum plaster applied in accordance with the requirements of Chapter 25.
i.Concrete walls shall be reinforced with horizontal and vertical temperature reinforcement as required by Chapter 19.
j.Studs are welded truss wire studs with 0.18 inch (No. 7 B.W. gage) flange wire and 0.18 inch (No. 7 B.W. gage) truss wires.
k.Nailable metal studs consist of two channel studs spot welded back to back with a crimped web forming a nailing groove.
l.Wood structural panels shall be permitted to be installed between the fire protection and the wood studs on either the interior or exterior side of the wood frame assemblies in this table, provided that the length of the fasteners used to attach the fire protection is increased by an amount not less than the thickness of the wood structural panel.
m.For studs with a slenderness ratio, le/d, greater than 33, the design stress shall be reduced to 78 percent of allowable F′c. For studs with a slenderness ratio, le/d, not exceeding 33, the design stress shall be reduced to 78 percent of the adjusted stress F′c calculated for studs having a slenderness ratio le/d of 33.
n.For properties of cooler or wallboard nails, see ASTM C514, ASTM C547 or ASTM F1667.
o.Generic fire-resistance ratings (those not designated as PROPRIETARY* in the listing) in the GA 600 shall be accepted as if herein specified.
p.NCMA TEK 5-8A shall be permitted for the design of fire walls.
q.The design stress of studs shall be equal to not more than 100 percent of the allowable F′c calculated in accordance with Section 2306.
TABLE 721.1(3)
MINIMUM PROTECTION FOR FLOOR AND ROOF SYSTEMSa, q
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 0.454 kg, 1 cubic foot = 0.0283 m3,
1 pound per square inch = 6.895 kPa, 1 pound per linear foot = 1.4882 kg/m.
a.Staples with equivalent holding power and penetration shall be permitted to be used as alternate fasteners to nails for attachment to wood framing.
b.Where the slab is in an unrestrained condition, minimum reinforcement cover shall be not less than 15/8 inches for 4 hours (siliceous aggregate only); 11/4 inches for 4 and 3 hours; 1 inch for 2 hours (siliceous aggregate only); and 3/4 inch for all other restrained and unrestrained conditions.
c.For all of the construction with gypsum wallboard described in this table, gypsum base for veneer plaster of the same size, thickness and core type shall be permitted to be substituted for gypsum wallboard, provided that attachment is identical to that specified for the wallboard, and the joints on the face layer are reinforced and the entire surface is covered with not less than 1/16-inch gypsum veneer plaster.
d.Slab thickness over steel joists measured at the joists for metal lath form and at the top of the form for steel form units.
e.
(a)The maximum allowable stress level for H-Series joists shall not exceed 22,000 psi.
(b)The allowable stress for K-Series joists shall not exceed 26,000 psi, the nominal depth of such joist shall be not less than 10 inches and the nominal joist weight shall be not less than 5 pounds per linear foot.
f.Cement plaster with 15 pounds of hydrated lime and 3 pounds of approved additives or admixtures per bag of cement.
g.Gypsum wallboard ceilings attached to steel framing shall be permitted to be suspended with 11/2-inch cold-formed carrying channels spaced 48 inches on center, that are suspended with No. 8 SWG galvanized wire hangers spaced 48 inches on center. Cross-furring channels are tied to the carrying channels with No. 18 SWG galvanized wire hangers spaced 48 inches on center. Cross-furring channels are tied to the carrying channels with No. 18 SWG galvanized wire (double strand) and spaced as required for direct attachment to the framing. This alternative is applicable to those steel framing assemblies recognized under Note q.
h.Six-inch hollow clay tile with 2-inch concrete slab above.
i.Four-inch hollow clay tile with 11/2-inch concrete slab above.
j.Thickness measured to bottom of steel form units.
k.Five-eighths inch of vermiculite gypsum plaster plus 1/2 inch of approved vermiculite acoustical plastic.
l.Furring channels spaced 12 inches on center.
m.Double wood floor shall be permitted to be either of the following:
(a)Subfloor of 1-inch nominal boarding, a layer of asbestos paper weighing not less than 14 pounds per 100 square feet and a layer of 1-inch nominal tongue-and-groove finished flooring.
(b)Subfloor of 1-inch nominal tongue-and-groove boarding or 15/32-inch wood structural panels with exterior glue and a layer of 1-inch nominal tongue-and-groove finished flooring or 19/32-inch wood structural panel finish flooring or a layer of Type I Grade M-1 particleboard not less than 5/8-inch thick.
n.The ceiling shall be permitted to be omitted over unusable space, and flooring shall be permitted to be omitted where unusable space occurs above.
o.For properties of cooler or wallboard nails, see ASTM C514, ASTM C547 or ASTM F1667.
p.Thickness measured on top of steel deck unit.
q.Generic fire-resistance ratings (those not designated as PROPRIETARY* in the listing) in the GA 600 shall be accepted as if herein specified.
721.1.1 Thickness of protective coverings.
721.1.3 Reinforcement for cast-in-place concrete column protection.
721.1.5 Bonded prestressed concrete tendons.
For members having a single tendon or more than one tendon installed with equal concrete cover measured from the nearest surface, the cover shall be not less than that set forth in Table 721.1(1). For members having multiple tendons installed with variable concrete cover, the average tendon cover shall be not less than that set forth in Table 721.1(1), provided that:
1.The clearance from each tendon to the nearest exposed surface is used to determine the average cover.
2.The clear cover for individual tendons shall not be less than one-half of that set forth in Table 721.1(1). A minimum cover of 3/4 inch (19.1 mm) for slabs and 1 inch (25 mm) for beams is required for any aggregate concrete.
3.For the purpose of establishing a fire-resistance rating, tendons having a clear covering less than that set forth in Table 721.1(1) shall not contribute more than 50 percent of the required ultimate moment capacity for members less than 350 square inches (0.226 m2) in cross-sectional area and 65 percent for larger members. For structural design purposes, however, tendons having a reduced cover are assumed to be fully effective.
SECTION 722
CALCULATED FIRE RESISTANCE
722.1 General.
The provisions of this section contain procedures by which the fire resistance of specific materials or combinations of materials is established by calculations. These procedures apply only to the information contained in this section and shall not be otherwise used. The calculated fire resistance of specific materials or combinations of materials shall be established by one of the following:
1.Concrete, concrete masonry and clay masonry assemblies shall be permitted in accordance with ACI 216.1/TMS 0216.
2.Precast and precast, prestressed concrete assemblies shall be permitted in accordance with PCI 124.
3.Steel assemblies shall be permitted in accordance with Chapter 5 of ASCE 29.
4.Exposed wood members and wood decking shall be permitted in accordance with Chapter 16 of ANSI/AWC NDS.
722.2 Concrete assemblies.
722.2.1 Concrete walls.
722.2.1.1 Cast-in-place or precast walls.
TABLE 722.2.1.1
MINIMUM EQUIVALENT THICKNESS OF CAST-IN-PLACE OR PRECAST CONCRETE WALLS, LOAD-BEARING OR NONLOAD-BEARING
| CONCRETE TYPE | MINIMUM SLAB THICKNESS (inches) FOR FIRE-RESISTANCE RATING OF | ||||
| 1 hour | 11/2 hours | 2 hours | 3 hours | 4 hours | |
| Siliceous | 3.5 | 4.3 | 5.0 | 6.2 | 7.0 |
| Carbonate | 3.2 | 4.0 | 4.6 | 5.7 | 6.6 |
| Sand-lightweight | 2.7 | 3.3 | 3.8 | 4.6 | 5.4 |
| Lightweight | 2.5 | 3.1 | 3.6 | 4.4 | 5.1 |
For SI: 1 inch = 25.4 mm.
722.2.1.1.1 Hollow-core precast wall panels.
722.2.1.1.2 Core spaces filled.
722.2.1.1.3 Tapered cross sections.
722.2.1.1.4 Ribbed or undulating surfaces.
The equivalent thickness of panels with ribbed or undulating surfaces shall be determined by one of the following expressions:
For s ≥ 4t, the thickness to be used shall be t
For s ≤ 2t, the thickness to be used shall be te
For 4t > s > 2t, the thickness to be used shall be
where:
s = Spacing of ribs or undulations.
t = Minimum thickness.
te = Equivalent thickness of the panel calculated as the net cross-sectional area of the panel divided by the width, in which the maximum thickness used in the calculation shall not exceed 2t.
722.2.1.2 Multiwythe walls.
TABLE 722.2.1.2(1)
VALUES OF Rn0.59FOR USE IN EQUATION 7-4
| TYPE OF MATERIAL | THICKNESS OF MATERIAL (inches) | |||||||||||
| 11/2 | 2 | 21/2 | 3 | 31/2 | 4 | 41/2 | 5 | 51/2 | 6 | 61/2 | 7 | |
| Siliceous aggregate concrete | 5.3 | 6.5 | 8.1 | 9.5 | 11.3 | 13.0 | 14.9 | 16.9 | 18.8 | 20.7 | 22.8 | 25.1 |
| Carbonate aggregate concrete | 5.5 | 7.1 | 8.9 | 10.4 | 12.0 | 14.0 | 16.2 | 18.1 | 20.3 | 21.9 | 24.7 | 27.2c |
| Sand-lightweight concrete | 6.5 | 8.2 | 10.5 | 12.8 | 15.5 | 18.1 | 20.7 | 23.3 | 26.0c | Note c | Note c | Note c |
| Lightweight concrete | 6.6 | 8.8 | 11.2 | 13.7 | 16.5 | 19.1 | 21.9 | 24.7 | 27.8c | Note c | Note c | Note c |
| Insulating concretea | 9.3 | 13.3 | 16.6 | 18.3 | 23.1 | 26.5c | Note c | Note c | Note c | Note c | Note c | Note c |
| Airspaceb | — | — | — | — | — | — | — | — | — | — | — | — |
For SI: 1 inch = 25.4 mm, 1 pound per cubic foot = 16.02 kg/m3.
a.Dry unit weight of 35 pcf or less and consisting of cellular, perlite or vermiculite concrete.
b.The Rn0.59value for one 1/2″ to 31/2″ airspace is 3.3. The Rn0.59value for two 1/2″ to 31/2″ airspaces is 6.7.
c.The fire-resistance rating for this thickness exceeds 4 hours.
FIGURE 722.2.1.2
FIRE-RESISTANCE RATINGS OF TWO-WYTHE CONCRETE WALLS
722.2.1.2.1 Two or more wythes.
The fire-resistance rating for wall panels consisting of two or more wythes shall be permitted to be determined by the formula:
722.2.1.2.2 Foam plastic insulation.
722.2.1.3 Joints between precast wall panels.
722.2.1.3.1 Ceramic fiber joint protection.
FIGURE 722.2.1.3.1
CERAMIC FIBER JOINT PROTECTION
722.2.1.4 Walls with gypsum wallboard or plaster finishes.
TABLE 722.2.1.4(1)
MULTIPLYING FACTOR FOR FINISHES ON NONFIRE-EXPOSED SIDE OF WALL
| TYPE OF FINISH APPLIED TO CONCRETE OR CONCRETE MASONRY WALL | TYPE OF AGGREGATE USED IN CONCRETE OR CONCRETE MASONRY | |||
| Concrete: siliceous or carbonate concrete masonry: siliceous or carbonate; solid claybrick | Concrete: sand-lightweight concrete masonry: clay tile; hollow clay brick; concrete masonry units of expanded shale and < 20% sand | Concrete: lightweight concrete masonry: concrete masonry units of expanded shale, expanded clay, expanded slag, or pumice < 20% sand | Concrete masonry: concrete masonry units of expanded slag, expanded clay, or pumice | |
| Portland cement-sand plaster | 1.00 | 0.75a | 0.75a | 0.50a |
| Gypsum-sand plaster | 1.25 | 1.00 | 1.00 | 1.00 |
| Gypsum-vermiculite or perlite plaster | 1.75 | 1.50 | 1.25 | 1.25 |
| Gypsum wallboard | 3.00 | 2.25 | 2.25 | 2.25 |
For SI: 1 inch = 25.4 mm.
a.For Portland cement-sand plaster 5/8 inch or less in thickness and applied directly to the concrete or concrete masonry on the nonfire-exposed side of the wall, the multiplying factor shall be 1.00.
TABLE 722.2.1.4(2)
TIME ASSIGNED TO FINISH MATERIALS ON FIRE-EXPOSED SIDE OF WALL
| FINISH DESCRIPTION | TIME (minutes) |
| Gypsum wallboard | |
3/8 inch | 10 |
1/2 inch | 15 |
5/8 inch | 20 |
2 layers of 3/8 inch | 25 |
1 layer of 3/8 inch, 1 layer of 1/2 inch | 35 |
2 layers of 1/2 inch | 40 |
| Type X gypsum wallboard | |
1/2 inch | 25 |
5/8 inch | 40 |
| Portland cement-sand plaster applied directly to concrete masonry | See Note a |
| Portland cement-sand plaster on metal lath | |
3/4 inch | 20 |
7/8 inch | 25 |
1 inch | 30 |
| Gypsum sand plaster on 3/8-inch gypsum lath | |
1/2 inch | 35 |
5/8 inch | 40 |
3/4 inch | 50 |
| Gypsum sand plaster on metal lath | |
3/4 inch | 50 |
7/8 inch | 60 |
1 inch | 80 |
722.2.1.4.1 Nonfire-exposed side.
722.2.1.4.2 Fire-exposed side.
722.2.1.4.3 Nonsymmetrical assemblies.
For a wall without finish on one side or having different types or thicknesses of finish on each side, the calculation procedures of Sections 722.2.1.4.1 and 722.2.1.4.2 shall be performed twice, assuming either side of the wall to be the fire-exposed side. The fire-resistance rating of the wall shall not exceed the lower of the two values.
Exception: For an exterior wall with a fire separation distance greater than 5 feet (1524 mm) the fire shall be assumed to occur on the interior side only.
722.2.1.4.4 Minimum concrete fire-resistance rating.
722.2.2 Concrete floor and roof slabs.
722.2.2.1 Reinforced and prestressed floors and roofs.
TABLE 722.2.2.1
MINIMUM SLAB THICKNESS (inches)
| CONCRETE TYPE | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |
| Siliceous | 3.5 | 4.3 | 5 | 6.2 | 7 |
| Carbonate | 3.2 | 4 | 4.6 | 5.7 | 6.6 |
| Sand-lightweight | 2.7 | 3.3 | 3.8 | 4.6 | 5.4 |
| Lightweight | 2.5 | 3.1 | 3.6 | 4.4 | 5.1 |
For SI: 1 inch = 25.4 mm.
722.2.2.1.1 Hollow-core prestressed slabs.
722.2.2.1.2 Slabs with sloping soffits.
FIGURE 722.2.2.1.2
DETERMINATION OF SLAB THICKNESS FOR SLOPING SOFFITS
722.2.2.1.3 Slabs with ribbed soffits.
The thickness of slabs with ribbed or undulating soffits (see Figure 722.2.2.1.3) shall be determined by one of the following expressions, whichever is applicable:
For s > 4t, the thickness to be used shall be t
For s ≤ 2t, the thickness to be used shall be te
For 4t > s > 2t, the thickness to be used shall be
FIGURE 722.2.2.1.3
SLABS WITH RIBBED OR UNDULATING SOFFITS
722.2.2.1.4 Flat plate concrete slabs with uniformly spaced hollow voids.
722.2.2.2 Multicourse floors.
FIGURE 722.2.2.2
FIRE-RESISTANCE RATINGS FOR TWO-COURSE CONCRETE FLOORS
722.2.2.3 Multicourse roofs.
FIGURE 722.2.2.3(1)
FIRE-RESISTANCE RATINGS FOR CONCRETE ROOF ASSEMBLIES
FIGURE 722.2.2.3(2)
FIRE-RESISTANCE RATINGS FOR CONCRETE ROOF ASSEMBLIES
722.2.2.3.1 Heat transfer.
722.2.2.4 Joints in precast slabs.
722.2.3 Concrete cover over reinforcement.
The minimum thickness of concrete cover over reinforcement in concrete slabs, reinforced beams and prestressed beams shall comply with this section.
TABLE 722.2.3(1)
COVER THICKNESS FOR REINFORCED CONCRETE FLOOR OR ROOF SLABS (inches)
| CONCRETE AGGREGATE TYPE | FIRE-RESISTANCE RATING (hours) | |||||||||
| Restrained | Unrestrained | |||||||||
| 1 | 11/2 | 2 | 3 | 4 | 1 | 11/2 | 2 | 3 | 4 | |
| Siliceous | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 1 | 11/4 | 15/8 |
| Carbonate | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 11/4 | 11/4 |
| Sand-lightweight or lightweight | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 11/4 | 11/4 |
For SI: 1 inch = 25.4 mm.
TABLE 722.2.3(2)
COVER THICKNESS FOR PRESTRESSED CONCRETE FLOOR OR ROOF SLABS (inches)
| CONCRETE AGGREGATE TYPE | FIRE-RESISTANCE RATING (hours) | |||||||||
| Restrained | Unrestrained | |||||||||
| 1 | 11/2 | 2 | 3 | 4 | 1 | 11/2 | 2 | 3 | 4 | |
| Siliceous | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 11/8 | 11/2 | 13/4 | 23/8 | 23/4 |
| Carbonate | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 1 | 13/8 | 15/8 | 21/8 | 21/4 |
| Sand-lightweight or lightweight | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | 1 | 13/8 | 11/2 | 2 | 21/4 |
For SI: 1 inch = 25.4 mm.
TABLE 722.2.3(3)
MINIMUM COVER FOR MAIN REINFORCING BARS OF REINFORCED CONCRETE BEAMSc(APPLICABLE TO ALL TYPES OF STRUCTURAL CONCRETE)
| RESTRAINED OR UNRESTRAINEDa | BEAM WIDTHb (inches) | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | ||
| Restrained | 5 | 3/4 | 3/4 | 3/4 | 1a | 11/4a |
7 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | |
| ≥10 | 3/4 | 3/4 | 3/4 | 3/4 | 3/4 | |
| Unrestrained | 5 | 3/4 | 1 | 11/4 | — | — |
| 7 | 3/4 | 3/4 | 3/4 | 13/4 | 3 | |
| ≥ 10 | 3/4 | 3/4 | 3/4 | 1 | 13/4 | |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a.Tabulated values for restrained assemblies apply to beams spaced more than 4 feet on center. For restrained beams spaced 4 feet or less on center, minimum cover of 3/4 inch is adequate for ratings of 4 hours or less.
b.For beam widths between the tabulated values, the minimum cover thickness can be determined by direct interpolation.
c.The cover for an individual reinforcing bar is the minimum thickness of concrete between the surface of the bar and the fire-exposed surface of the beam. For beams in which several bars are used, the cover for corner bars used in the calculation shall be reduced to one-half of the actual value. The cover for an individual bar must be not less than one-half of the value given in Table 722.2.3(3) nor less than 3/4 inch.
TABLE 722.2.3(4)
MINIMUM COVER FOR PRESTRESSED CONCRETE BEAMS 8 INCHES OR GREATER IN WIDTHb
| RESTRAINED OR UNRESTRAINEDa | CONCRETE AGGREGATE TYPE | BEAM WIDTH (inches) | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |||
| Restrained | Carbonate or siliceous | 8 | 11/2 | 11/2 | 11/2 | 13/4a | 21/2a |
| Carbonate or siliceous | ≥ 12 | 11/2 | 11/2 | 11/2 | 11/2 | 17/8a | |
| Sand lightweight | 8 | 11/2 | 11/2 | 11/2 | 11/2 | 2a | |
| Sand lightweight | ≥ 12 | 11/2 | 11/2 | 11/2 | 11/2 | 15/8a | |
| Unrestrained | Carbonate or siliceous | 8 | 11/2 | 13/4 | 21/2 | 5c | — |
| Carbonate or siliceous | ≥ 12 | 11/2 | 11/2 | 17/8a | 21/2 | 3 | |
| Sand lightweight | 8 | 11/2 | 11/2 | 2 | 31/4 | — | |
| Sand lightweight | ≥ 12 | 11/2 | 11/2 | 15/8 | 2 | 21/2 | |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
a.Tabulated values for restrained assemblies apply to beams spaced more than 4 feet on center. For restrained beams spaced 4 feet or less on center, minimum cover of 3/4 inch is adequate for 4-hour ratings or less.
b.For beam widths between 8 inches and 12 inches, minimum cover thickness can be determined by direct interpolation.
c.Not practical for 8-inch-wide beam but shown for purposes of interpolation.
TABLE 722.2.3(5)
MINIMUM COVER FOR PRESTRESSED CONCRETE BEAMS OF ALL WIDTHS
| RESTRAINED OR UNRESTRAINEDa | CONCRETE AGGREGATE TYPE | BEAM AREAb A (square inches) | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |||
| Restrained | All | 40 ≤ A ≤ 150 | 11/2 | 11/2 | 2 | 21/2 | — |
| Carbonate or siliceous | 150 < A ≤ 300 | 11/2 | 11/2 | 11/2 | 13/4 | 21/2 | |
| 300 < A | 11/2 | 11/2 | 11/2 | 11/2 | 2 | ||
| Sand lightweight | 150 < A | 11/2 | 11/2 | 11/2 | 11/2 | 2 | |
| Unrestrained | All | 40 ≤ A ≤ 150 | 2 | 21/2 | — | — | — |
| Carbonate or siliceous | 150 < A ≤ 300 | 11/2 | 13/4 | 21/2 | — | — | |
| 300 < A | 11/2 | 11/2 | 2 | 3c | 4c | ||
| Sand lightweight | 150 < A | 11/2 | 11/2 | 2 | 3c | 4c | |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 square inch = 645.2 mm2.
a.Tabulated values for restrained assemblies apply to beams spaced more than 4 feet on center. For restrained beams spaced 4 feet or less on center, minimum cover of 3/4 inch is adequate for 4-hour ratings or less.
b.The cross-sectional area of a stem is permitted to include a portion of the area in the flange, provided that the width of the flange used in the calculation does not exceed three times the average width of the stem.
c.U-shaped or hooped stirrups spaced not to exceed the depth of the member and having a minimum cover of 1 inch shall be provided.
722.2.3.1 Slab cover.
722.2.3.3 Prestressed beam cover.
722.2.3.3.1 Calculating concrete cover.
722.2.4 Concrete columns.
TABLE 722.2.4
MINIMUM DIMENSION OF CONCRETE COLUMNS (inches)
| TYPES OF CONCRETE | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2a | 3a | 4b | |
| Siliceous | 8 | 9 | 10 | 12 | 14 |
| Carbonate | 8 | 9 | 10 | 11 | 12 |
| Sand-lightweight | 8 | 81/2 | 9 | 101/2 | 12 |
For SI: 1 inch = 25 mm.
a.The minimum dimension is permitted to be reduced to 8 inches for rectangular columns with two parallel sides not less than 36 inches in length.
b.The minimum dimension is permitted to be reduced to 10 inches for rectangular columns with two parallel sides not less than 36 inches in length.
722.2.4.1 Minimum size.
722.2.4.1.2 Concrete strength greater than 12,000 psi.
722.2.4.2 Minimum cover for R/C columns.
722.2.4.3 Tie and spiral reinforcement.
For concrete columns made with concrete having a specified compressive strength, f’c, greater than 12,000 psi (82.7 MPa), tie and spiral reinforcement shall comply with the following:
1.The free ends of rectangular ties shall terminate with a 135-degree (2.4 rad) standard tie hook.
2.The free ends of circular ties shall terminate with a 90-degree (1.6 rad) standard tie hook.
3.The free ends of spirals, including at lap splices, shall terminate with a 90-degree (1.6 rad) standard tie hook.
The hook extension at the free end of ties and spirals shall be the larger of six bar diameters and the extension required by Section 25.3.2 of ACI 318. Hooks shall project into the core of the column.
722.2.4.4 Columns built into walls.
The minimum dimensions of Table 722.2.4 do not apply to a reinforced concrete column that is built into a concrete or masonry wall provided that all of the following are met:
Where openings in the wall are not protected as required by Section 716, the minimum dimension of columns required to have a fire-resistance rating of 3 hours or less shall be 8 inches (203 mm), and 10 inches (254 mm) for columns required to have a fire-resistance rating of 4 hours, regardless of the type of aggregate used in the concrete.
722.3 Concrete masonry.
722.3.1 Equivalent thickness.
722.3.1.1 Concrete masonry unit plus finishes.
The equivalent thickness of concrete masonry assemblies, Tea, shall be computed as the sum of the equivalent thickness of the concrete masonry unit, Te, as determined by Section 722.3.1.2, 722.3.1.3 or 722.3.1.4, plus the equivalent thickness of finishes, Tef, determined in accordance with Section 722.3.2:
722.3.1.3 Solid grouted construction.
722.3.1.4 Airspaces and cells filled with loose-fill material.
722.3.2 Concrete masonry walls.
TABLE 722.3.2
MINIMUM EQUIVALENT THICKNESS (inches) OF BEARING OR NONBEARING CONCRETE MASONRY WALLSa, b, c, d
| TYPE OF AGGREGATE | FIRE-RESISTANCE RATING (hours) | ||||||||||||||
| 1/2 | 3/4 | 1 | 11/4 | 11/2 | 13/4 | 2 | 21/4 | 21/2 | 23/4 | 3 | 31/4 | 31/2 | 33/4 | 4 | |
| Pumice or expanded slag | 1.5 | 1.9 | 2.1 | 2.5 | 2.7 | 3.0 | 3.2 | 3.4 | 3.6 | 3.8 | 4.0 | 4.2 | 4.4 | 4.5 | 4.7 |
| Expanded shale, clay or slate | 1.8 | 2.2 | 2.6 | 2.9 | 3.3 | 3.4 | 3.6 | 3.8 | 4.0 | 4.2 | 4.4 | 4.6 | 4.8 | 4.9 | 5.1 |
| Limestone, cinders or unexpanded slag | 1.9 | 2.3 | 2.7 | 3.1 | 3.4 | 3.7 | 4.0 | 4.3 | 4.5 | 4.8 | 5.0 | 5.2 | 5.5 | 5.7 | 5.9 |
| Calcareous or siliceous gravel | 2.0 | 2.4 | 2.8 | 3.2 | 3.6 | 3.9 | 4.2 | 4.5 | 4.8 | 5.0 | 5.3 | 5.5 | 5.8 | 6.0 | 6.2 |
For SI: 1 inch = 25.4 mm.
a.Values between those shown in the table can be determined by direct interpolation.
b.Where combustible members are framed into the wall, the thickness of solid material between the end of each member and the opposite face of the wall, or between members set in from opposite sides, shall be not less than 93 percent of the thickness shown in the table.
c.Requirements of ASTM C55, ASTM C73, ASTM C90 or ASTM C744 shall apply.
d.Minimum required equivalent thickness corresponding to the hourly fire-resistance rating for units with a combination of aggregate shall be determined by linear interpolation based on the percent by volume of each aggregate used in manufacture.
722.3.2.1 Finish on nonfire-exposed side.
722.3.2.2 Finish on fire-exposed side.
722.3.2.3 Nonsymmetrical assemblies.
For a wall without finish on one side or having different types or thicknesses of finish on each side, the calculation procedures of this section shall be performed twice, assuming either side of the wall to be the fire-exposed side. The fire-resistance rating of the wall shall not exceed the lower of the two values calculated.
Exception: For exterior walls with a fire separation distance greater than 5 feet (1524 mm), the fire shall be assumed to occur on the interior side only.
722.3.2.4 Minimum concrete masonry fire-resistance rating.
722.3.2.5 Attachment of finishes.
Installation of finishes shall be as follows:
1.Gypsum wallboard and gypsum lath applied to concrete masonry or concrete walls shall be secured to wood or steel furring members spaced not more than 16 inches (406 mm) on center (o.c.).
2.Gypsum wallboard shall be installed with the long dimension parallel to the furring members and shall have all joints finished.
3.Other aspects of the installation of finishes shall comply with the applicable provisions of Chapters 7 and 25.
722.3.3 Multiwythe masonry walls.
The fire-resistance rating of wall assemblies constructed of multiple wythes of masonry materials shall be permitted to be based on the fire-resistance rating period of each wythe and the continuous airspace between each wythe in accordance with the following formula:
722.3.4 Concrete masonry lintels.
TABLE 722.3.4
MINIMUM COVER OF LONGITUDINAL REINFORCEMENT IN FIRE-RESISTANCE-RATED REINFORCED CONCRETE MASONRY LINTELS (inches)
| NOMINAL WIDTH OF LINTEL (inches) | FIRE-RESISTANCE RATING (hours) | |||
| 1 | 2 | 3 | 4 | |
| 6 | 11/2 | 2 | — | — |
| 8 | 11/2 | 11/2 | 13/4 | 3 |
| 10 or greater | 11/2 | 11/2 | 11/2 | 13/4 |
For SI: 1 inch = 25.4 mm.
722.3.5 Concrete masonry columns.
TABLE 722.3.5
MINIMUM DIMENSION OF CONCRETE MASONRY COLUMNS (inches)
| FIRE-RESISTANCE RATING (hours) | |||
| 1 | 2 | 3 | 4 |
| 8 inches | 10 inches | 12 inches | 14 inches |
For SI: 1 inch = 25.4 mm.
722.4 Clay brick and tile masonry.
722.4.1 Masonry walls.
TABLE 722.4.1(1)
FIRE-RESISTANCE PERIODS OF CLAY MASONRY WALLS
For SI: 1 inch = 25.4 mm.
a.Equivalent thickness as determined from Section 722.4.1.1.
b.Calculated fire resistance between the hourly increments specified shall be determined by linear interpolation.
c.Where combustible members are framed in the wall, the thickness of solid material between the end of each member and the opposite face of the wall, or between members set in from opposite sides, shall be not less than 93 percent of the thickness shown.
d.For units in which the net cross-sectional area of cored brick in any plane parallel to the surface containing the cores is not less than 75 percent of the gross cross-sectional area measured in the same plane.
TABLE 722.4.1(2)
FIRE-RESISTANCE RATINGS FOR BEARING STEEL FRAME BRICK VENEER WALLS OR PARTITIONS
| WALL OR PARTITION ASSEMBLY | PLASTER SIDE EXPOSED (hours) | BRICK FACED SIDE EXPOSED (hours) |
| Outside facing of steel studs: 1/2″ wood fiberboard sheathing next to studs, 3/4″ airspace formed with 3/4″ × 15/8″ wood strips placed over the fiberboard and secured to the studs; metal or wire lath nailed to such strips, 33/4″ brick veneer held in place by filling 3/4″ airspace between the brick and lath with mortar. Inside facing of studs: 3/4″ unsanded gypsum plaster on metal or wire lath attached to 5/16″ wood strips secured to edges of the studs. | 1.5 | 4 |
| Outside facing of steel studs: 1″ insulation board sheathing attached to studs, 1″ airspace, and 33/4″ brick veneer attached to steel frame with metal ties every 5th course. Inside facing of studs: 7/8″ sanded gypsum plaster (1:2 mix) applied on metal or wire lath attached directly to the studs. | 1.5 | 4 |
| Same as previous assembly except use 7/8″ vermiculite-gypsum plaster or 1″ sanded gypsum plaster (1:2 mix) applied to metal or wire. | 2 | 4 |
| Outside facing of steel studs: 1/2″ gypsum sheathing board, attached to studs, and 33/4″ brick veneer attached to steel frame with metal ties every 5th course. Inside facing of studs: 1/2″ sanded gypsum plaster (1:2 mix) applied to 1/2″ perforated gypsum lath securely attached to studs and having strips of metal lath 3 inches wide applied to all horizontal joints of gypsum lath. | 2 | 4 |
For SI: 1 inch = 25.4 mm.
TABLE 722.4.1(3)
VALUES OF Rn0.59
| Rn 0.59 | R (hours) |
| 1 | 1.0 |
| 2 | 1.50 |
| 3 | 1.91 |
| 4 | 2.27 |
TABLE 722.4.1(4)
COEFFICIENTS FOR PLASTER, pl a
| THICKNESS OF PLASTER (inch) | ONE SIDE | TWO SIDES |
| 1/2 | 0.3 | 0.6 |
| 5/8 | 0.37 | 0.75 |
| 3/4 | 0.45 | 0.90 |
For SI: 1 inch = 25.4 mm.
a.Values specified in the table are for 1:3 sanded gypsum plaster.
TABLE 722.4.1(5)
REINFORCED MASONRY LINTELS
| NOMINAL LINTEL WIDTH (inches) | MINIMUM LONGITUDINAL REINFORCEMENT COVER FOR FIRE RESISTANCE (inches) | |||
| 1 hour | 2 hours | 3 hours | 4 hours | |
| 6 | 11/2 | 2 | NP | NP |
| 8 | 11/2 | 11/2 | 13/4 | 3 |
| 10 or more | 11/2 | 11/2 | 11/2 | 13/4 |
For SI: 1 inch = 25.4 mm.
NP = Not Permitted.
TABLE 722.4.1(6)
REINFORCED CLAY MASONRY COLUMNS
| COLUMN SIZE | FIRE-RESISTANCE RATING (hours) | |||
| 1 | 2 | 3 | 4 | |
| Minimum column dimension (inches) | 8 | 10 | 12 | 14 |
For SI: 1 inch = 25.4 mm.
722.4.1.1 Equivalent thickness.
The fire-resistance ratings of walls or partitions constructed of solid or hollow clay masonry units shall be determined from Table 722.4.1(1) or Table 722.4.1(2). The equivalent thickness of the clay masonry unit shall be determined by Equation 7-8 where using Table 722.4.1(1). The fire-resistance rating determined from Table 722.4.1(1) shall be permitted to be used in the calculated fire-resistance rating procedure in Section 722.4.2.
where:
Te = The equivalent thickness of the clay masonry unit (inches).
Vn = The net volume of the clay masonry unit (inch3).
L = The specified length of the clay masonry unit (inches).
H = The specified height of the clay masonry unit (inches).
722.4.1.1.1 Hollow clay units.
722.4.1.1.2 Solid grouted clay units.
722.4.1.1.3 Units with filled cores.
722.4.1.2 Plaster finishes.
Where plaster is applied to the wall, the total fire-resistance rating shall be determined by the formula:
Values for Rn0.59for use in Equation 7-9 are given in Table 722.4.1(3). Coefficients for thickness of plaster shall be selected from Table 722.4.1(4) based on the actual thickness of plaster applied to the wall or partition and whether one or two sides of the wall are plastered.
722.4.1.3 Multiwythe walls with airspace.
Where a continuous airspace separates multiple wythes of the wall or partition, the total fire-resistance rating shall be determined by the formula:
where:
R = The fire-resistance rating of the assembly (hours).
R1, R2 and Rn = The fire-resistance rating of the individual wythes (hours).
as = Coefficient for continuous airspace.
Values for Rn0.59for use in Equation 7-10 are given in Table 722.4.1(3). The coefficient for each continuous airspace of 1/2 inch to 31/2 inches (12.7 to 89 mm) separating two individual wythes shall be 0.3.
722.4.1.4 Nonsymmetrical assemblies.
For a wall without finish on one side or having different types or thicknesses of finish on each side, the calculation procedures of this section shall be performed twice, assuming either side to be the fire-exposed side of the wall. The fire resistance of the wall shall not exceed the lower of the two values determined.
Exception: For exterior walls with a fire separation distance greater than 5 feet (1524 mm), the fire shall be assumed to occur on the interior side only.
722.4.2 Multiwythe walls.
The fire-resistance rating for walls or partitions consisting of two or more dissimilar wythes shall be permitted to be determined by the formula:
where:
R = The fire-resistance rating of the assembly (hours).
R1, R2 and Rn = The fire-resistance rating of the individual wythes (hours).
Values for Rn0.59 for use in Equation 7-11 are given in Table 722.4.1(3).
722.4.2.1 Multiwythe walls of different material.
722.5 Steel assemblies.
722.5.1 Structural steel columns.
TABLE 722.5.1(1)
W/D RATIOS FOR STEEL COLUMNS
| STRUCTURAL SHAPE | CONTOUR PROFILE | BOX PROFILE |
| W14 × 233 | 2.55 | 3.65 |
| × 211 | 2.32 | 3.35 |
| × 193 | 2.14 | 3.09 |
| × 176 | 1.96 | 2.85 |
| × 159 | 1.78 | 2.60 |
| × 145 | 1.64 | 2.39 |
| × 132 | 1.56 | 2.25 |
| × 120 | 1.42 | 2.06 |
| × 109 | 1.29 | 1.88 |
| × 99 | 1.18 | 1.72 |
| × 90 | 1.08 | 1.58 |
| × 82 | 1.23 | 1.68 |
| × 74 | 1.12 | 1.53 |
| × 68 | 1.04 | 1.41 |
| × 61 | 0.928 | 1.28 |
| × 53 | 0.915 | 1.21 |
| × 48 | 0.835 | 1.10 |
| × 43 | 0.752 | 0.99 |
| W12 × 190 | 2.50 | 3.51 |
| × 170 | 2.26 | 3.20 |
| × 152 | 2.04 | 2.90 |
| × 136 | 1.86 | 2.63 |
| × 120 | 1.65 | 2.36 |
| × 106 | 1.47 | 2.11 |
| × 96 | 1.34 | 1.93 |
| × 87 | 1.22 | 1.76 |
| × 79 | 1.11 | 1.61 |
| × 72 | 1.02 | 1.48 |
| × 65 | 0.925 | 1.35 |
| × 58 | 0.925 | 1.31 |
| × 53 | 0.855 | 1.20 |
| × 50 | 0.909 | 1.23 |
| × 45 | 0.829 | 1.12 |
| × 40 | 0.734 | 1.00 |
| W10 × 112 | 1.81 | 2.57 |
| × 100 | 1.64 | 2.33 |
| × 88 | 1.45 | 2.08 |
| × 77 | 1.28 | 1.85 |
| × 68 | 1.15 | 1.66 |
| × 60 | 1.01 | 1.48 |
| × 54 | 0.922 | 1.34 |
| × 49 | 0.84 | 1.23 |
| × 45 | 0.888 | 1.24 |
| × 39 | 0.78 | 1.09 |
| × 33 | 0.661 | 0.93 |
| W8 × 67 | 1.37 | 1.94 |
| × 58 | 1.20 | 1.71 |
| × 48 | 1.00 | 1.44 |
| × 40 | 0.849 | 1.23 |
| × 35 | 0.749 | 1.08 |
| × 31 | 0.665 | 0.97 |
| × 28 | 0.688 | 0.96 |
| × 24 | 0.591 | 0.83 |
| × 21 | 0.577 | 0.77 |
| × 18 | 0.499 | 0.67 |
| W6 ×25 | 0.696 | 1.00 |
| × 20 | 0.563 | 0.82 |
| × 16 | 0.584 | 0.78 |
| × 15 | 0.431 | 0.63 |
| × 12 | 0.448 | 0.60 |
| × 9 | 0.338 | 0.46 |
| W5 ×19 | 0.644 | 0.93 |
| × 16 | 0.55 | 0.80 |
| W4 ×13 | 0.556 | 0.79 |
For SI: 1 pound per linear foot per inch = 0.059 kg/m/mm.
FIGURE 722.5.1(1)
DETERMINATION OF THE HEATED PERIMETER OF STRUCTURAL STEEL COLUMNS
TABLE 722.5.1(2)
PROPERTIES OF CONCRETE
| PROPERTY | NORMAL-WEIGHT CONCRETE | STRUCTURAL LIGHTWEIGHT CONCRETE |
| Thermal conductivity (kc) | 0.95 Btu/hr × ft × °F | 0.35 Btu/hr × ft × °F |
| Specific heat (cc) | 0.20 Btu/lb °F | 0.20 Btu/lb °F |
| Density (Pc) | 145 lb/ft3 | 110 lb/ft3 |
| Equilibrium (free) moisture content (m) by volume | 4% | 5% |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 lb/ft3= 16.0185 kg/m3, Btu/hr × ft × °F = 1.731 W/(m × K).
1.Structural steel column, either wide flange or tubular shapes.
2.Type X gypsum board or gypsum panel products in accordance with ASTM C1177, C1178, C1278, C1396 or C1658. The total thickness of gypsum board or gypsum panel products calculated as h in Section 722.5.1.2 shall be applied vertically to an individual column using one of the following methods:
1.As a single layer without horizontal joints.
2.As multiple layers with horizontal joints not permitted in any layer.
3.As multiple layers with horizontal joints staggered not less than 12 inches vertically between layers and not less than 8 feet vertically in any single layer. The total required thickness of gypsum board or gypsum panel products shall be determined on the basis of the specified fire-resistance rating and the weight-to-heated-perimeter ratio (W/D) of the column. For fire-resistance ratings of 2 hours or less, one of the required layers of gypsum board or gypsum panel product may be applied to the exterior of the sheet steel column covers with 1-inch long Type S screws spaced 1 inch from the wallboard edge and 8 inches on center. For such installations, 0.0149-inch minimum thickness galvanized steel corner beads with 11/2-inch legs shall be attached to the wallboard with Type S screws spaced 12 inches on center.
3.For fire-resistance ratings of 3 hours or less, the column covers shall be fabricated from 0.0239-inch minimum thickness galvanized or stainless steel. For 4-hour fire-resistance ratings, the column covers shall be fabricated from 0.0239-inch minimum thickness stainless steel. The column covers shall be erected with the Snap Lock or Pittsburgh joint details. For fire-resistance ratings of 2 hours or less, column covers fabricated from 0.0269-inch minimum thickness galvanized or stainless steel shall be permitted to be erected with lap joints. The lap joints shall be permitted to be located anywhere around the perimeter of the column cover. The lap joints shall be secured with 1/2-inch-long No. 8 sheet metal screws spaced 12 inches on center. The column covers shall be provided with a minimum expansion clearance of 1/8 inch per linear foot between the ends of the cover and any restraining construction.
FIGURE 722.5.1(2)
GYPSUM-PROTECTED STRUCTURAL STEEL COLUMNS WITH SHEET STEEL COLUMN COVERS
TABLE 722.5.1(3)
THERMAL CONDUCTIVITY OF CONCRETE OR CLAY MASONRY UNITS
| DENSITY (dm) OF UNITS (lb/ft3) | THERMAL CONDUCTIVITY (K) OF UNITS (Btu/hr · ft · °F) |
| Concrete Masonry Units | |
| 80 | 0.207 |
| 85 | 0.228 |
| 90 | 0.252 |
| 95 | 0.278 |
| 100 | 0.308 |
| 105 | 0.340 |
| 110 | 0.376 |
| 115 | 0.416 |
| 120 | 0.459 |
| 125 | 0.508 |
| 130 | 0.561 |
| 135 | 0.620 |
| 140 | 0.685 |
| 145 | 0.758 |
| 150 | 0.837 |
| Clay Masonry Units | |
| 120 | 1.25 |
| 130 | 2.25 |
For SI: 1 pound per cubic foot = 16.0185 kg/m3, Btu/hr × ft × °F = 1.731 W/(m × K)
1.Structural steel column, either wide flange or tubular shapes.
2.15/8-inch deep studs fabricated from 0.0179-inch minimum thickness galvanized steel with 15/16 or 17/16-inch legs. The length of the steel studs shall be 1/2 inch less than the height of the assembly.
3.Type X gypsum board or gypsum panel products in accordance with ASTM C1177, C1178, C1278, C1396 or C1658. The total thickness of gypsum board or gypsum panel products calculated as h in Section 722.5.1.2 shall be applied vertically to an individual column using one of the following methods:
1.As a single layer without horizontal joints.
2.As multiple layers with horizontal joints not permitted in any layer.
3.As multiple layers with horizontal joints staggered not less than 12 inches vertically between layers and not less than 8 feet vertically in any single layer. The total required thickness of gypsum board or gypsum panel products shall be determined on the basis of the specified fire-resistance rating and the weight-to-heated-perimeter ratio (W/D) of the column.
4.Galvanized 0.0149-inch minimum thickness steel corner beads with 11/2- inch legs attached to the gypsum board or gypsum panel products with 1-inch-long Type S screws spaced 12 inches on center.
5.No. 18 SWG steel tie wires spaced 24 inches on center.
6.Sheet metal angles with 2-inch legs fabricated from 0.0221-inch minimum thickness galvanized steel.
7.Type S screws, 1 inch long, shall be used for attaching the first layer of gypsum board or gypsum panel product to the steel studs and the third layer to the sheet metal angles at 24 inches on center. Type S screws 13/4 inches long shall be used for attaching the second layer of gypsum board or gypsum panel product to the steel studs and the fourth layer to the sheet metal angles at 12 inches on center. Type S screws 21/4 inches long shall be used for attaching the third layer of gypsum board or gypsum panel product to the steel studs at 12 inches on center.
FIGURE 722.5.1(3)
GYPSUM-PROTECTED STRUCTURAL STEEL COLUMNS WITH STEEL STUD/SCREW ATTACHMENT SYSTEM
TABLE 722.5.1(4)
WEIGHT-TO-HEATED-PERIMETER RATIOS (W/D) FOR TYPICAL WIDE FLANGE BEAM AND GIRDER SHAPES
| STRUCTURAL SHAPE | CONTOUR PROFILE | BOX PROFILE |
| W36 × 300 | 2.50 | 3.33 |
| × 280 | 2.35 | 3.12 |
| × 260 | 2.18 | 2.92 |
| × 245 | 2.08 | 2.76 |
| × 230 | 1.95 | 2.61 |
| × 210 | 1.96 | 2.45 |
| × 194 | 1.81 | 2.28 |
| × 182 | 1.72 | 2.15 |
| × 170 | 1.60 | 2.01 |
| × 160 | 1.51 | 1.90 |
| × 150 | 1.43 | 1.79 |
| × 135 | 1.29 | 1.63 |
| W33 × 241 | 2.13 | 2.86 |
| × 221 | 1.97 | 2.64 |
| × 201 | 1.79 | 2.42 |
| × 152 | 1.53 | 1.94 |
| × 141 | 1.43 | 1.80 |
| × 130 | 1.32 | 1.67 |
| × 118 | 1.21 | 1.53 |
| W30 × 211 | 2.01 | 2.74 |
| × 191 | 1.85 | 2.50 |
| × 173 | 1.66 | 2.28 |
| × 132 | 1.47 | 1.85 |
| × 124 | 1.39 | 1.75 |
| × 116 | 1.30 | 1.65 |
| × 108 | 1.21 | 1.54 |
| × 99 | 1.12 | 1.42 |
| W27 × 178 | 1.87 | 2.55 |
| × 161 | 1.70 | 2.33 |
| × 146 | 1.55 | 2.12 |
| × 114 | 1.39 | 1.76 |
| × 102 | 1.24 | 1.59 |
| × 94 | 1.15 | 1.47 |
| × 84 | 1.03 | 1.33 |
| W24 × 162 | 1.88 | 2.57 |
| × 146 | 1.70 | 2.34 |
| × 131 | 1.54 | 2.12 |
| × 117 | 1.38 | 1.91 |
| × 104 | 1.24 | 1.71 |
| × 94 | 1.28 | 1.63 |
| × 84 | 1.15 | 1.47 |
| × 76 | 1.05 | 1.34 |
| W24 × 68 | 0.942 | 1.21 |
| × 62 | 0.934 | 1.14 |
| × 55 | 0.828 | 1.02 |
| W21 × 147 | 1.87 | 2.60 |
| × 132 | 1.68 | 2.35 |
| × 122 | 1.57 | 2.19 |
| × 111 | 1.43 | 2.01 |
| × 101 | 1.30 | 1.84 |
| × 93 | 1.40 | 1.80 |
| × 83 | 1.26 | 1.62 |
| × 73 | 1.11 | 1.44 |
| × 68 | 1.04 | 1.35 |
| W21 × 62 | 0.952 | 1.23 |
| × 57 | 0.952 | 1.17 |
| × 50 | 0.838 | 1.04 |
| × 44 | 0.746 | 0.92 |
| W18 × 119 | 1.72 | 2.42 |
| × 106 | 1.55 | 2.18 |
| × 97 | 1.42 | 2.01 |
| × 86 | 1.27 | 1.80 |
| × 76 | 1.13 | 1.60 |
| × 71 | 1.22 | 1.59 |
| × 65 | 1.13 | 1.47 |
| × 60 | 1.04 | 1.36 |
| × 55 | 0.963 | 1.26 |
| × 50 | 0.88 | 1.15 |
| × 46 | 0.878 | 1.09 |
| × 40 | 0.768 | 0.96 |
| × 35 | 0.672 | 0.85 |
| W16 × 100 | 1.59 | 2.25 |
| × 89 | 1.43 | 2.03 |
| × 77 | 1.25 | 1.78 |
| × 67 | 1.09 | 1.56 |
| × 57 | 1.09 | 1.43 |
| × 50 | 0.962 | 1.26 |
| × 45 | 0.870 | 1.15 |
| × 40 | 0.780 | 1.03 |
| × 36 | 0.702 | 0.93 |
| × 31 | 0.661 | 0.83 |
| × 26 | 0.558 | 0.70 |
| W14 × 132 | 1.89 | 3.00 |
| × 120 | 1.71 | 2.75 |
| × 109 | 1.57 | 2.52 |
| W14 × 99 | 1.43 | 2.31 |
| × 90 | 1.31 | 2.11 |
| × 82 | 1.45 | 2.12 |
| × 74 | 1.32 | 1.93 |
| × 68 | 1.22 | 1.78 |
| × 61 | 1.10 | 1.61 |
| × 53 | 1.06 | 1.48 |
| × 48 | 0.970 | 1.35 |
| W14 × 43 | 0.874 | 1.22 |
| × 38 | 0.809 | 1.09 |
| × 34 | 0.725 | 0.98 |
| × 30 | 0.644 | 0.87 |
| × 26 | 0.628 | 0.79 |
| × 22 | 0.534 | 0.68 |
| W12 × 87 | 1.47 | 2.34 |
| × 79 | 1.34 | 2.14 |
| × 72 | 1.23 | 1.97 |
| × 65 | 1.11 | 1.79 |
| × 58 | 1.10 | 1.69 |
| × 53 | 1.02 | 1.55 |
| × 50 | 1.06 | 1.54 |
| × 45 | 0.974 | 1.40 |
| × 40 | 0.860 | 1.25 |
| × 35 | 0.810 | 1.11 |
| × 30 | 0.699 | 0.96 |
| × 26 | 0.612 | 0.84 |
| × 22 | 0.623 | 0.77 |
| × 19 | 0.540 | 0.67 |
| × 16 | 0.457 | 0.57 |
| × 14 | 0.405 | 0.50 |
| W10 × 112 | 2.17 | 3.38 |
| × 100 | 1.97 | 3.07 |
| × 88 | 1.74 | 2.75 |
| × 77 | 1.54 | 2.45 |
| × 68 | 1.38 | 2.20 |
| × 60 | 1.22 | 1.97 |
| × 54 | 1.11 | 1.79 |
| × 49 | 1.01 | 1.64 |
| × 45 | 1.06 | 1.59 |
| × 39 | 0.94 | 1.40 |
| × 33 | 0.77 | 1.20 |
| W10 × 30 | 0.806 | 1.12 |
| × 26 | 0.708 | 0.98 |
| × 22 | 0.606 | 0.84 |
| × 19 | 0.607 | 0.78 |
| × 17 | 0.543 | 0.70 |
| × 15 | 0.484 | 0.63 |
| × 12 | 0.392 | 0.51 |
| W8 × 67 | 1.65 | 2.55 |
| × 58 | 1.44 | 2.26 |
| × 48 | 1.21 | 1.91 |
| × 40 | 1.03 | 1.63 |
| × 35 | 0.907 | 1.44 |
| × 31 | 0.803 | 1.29 |
| × 28 | 0.819 | 1.24 |
| × 24 | 0.704 | 1.07 |
| × 21 | 0.675 | 0.96 |
| × 18 | 0.583 | 0.84 |
| × 15 | 0.551 | 0.74 |
| × 13 | 0.483 | 0.65 |
| × 10 | 0.375 | 0.51 |
| W6 × 25 | 0.839 | 1.33 |
| × 20 | 0.678 | 1.09 |
| × 16 | 0.684 | 0.96 |
| × 15 | 0.521 | 0.83 |
| × 12 | 0.526 | 0.75 |
| × 9 | 0.398 | 0.57 |
| W5 × 19 | 0.776 | 1.24 |
| × 16 | 0.664 | 1.07 |
| W4 × 13 | 0.670 | 1.05 |
For SI: 1 pound per linear foot per inch = 0.059 kg/m/mm.
FIGURE 722.5.1(4)
FIRE RESISTANCE OF STRUCTURAL STEEL COLUMNS PROTECTED WITH VARIOUS THICKNESSES OF TYPE X GYPSUM WALLBOARD
TABLE 722.5.1(5)
FIRE RESISTANCE OF CONCRETE MASONRY PROTECTED STEEL COLUMNS
| COLUMN SIZE | CONCRETE MASONRY DENSITY POUNDS PER CUBIC FOOT | MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CONCRETE MASONRY PROTECTION ASSEMBLY, Te (inches) | |||
| 1 hour | 2 hours | 3 hours | 4 hours | ||
| W14 × 82 | 80 | 0.74 | 1.61 | 2.36 | 3.04 |
| 100 | 0.89 | 1.85 | 2.67 | 3.40 | |
| 110 | 0.96 | 1.97 | 2.81 | 3.57 | |
| 120 | 1.03 | 2.08 | 2.95 | 3.73 | |
| W14 × 68 | 80 | 0.83 | 1.70 | 2.45 | 3.13 |
| 100 | 0.99 | 1.95 | 2.76 | 3.49 | |
| 110 | 1.06 | 2.06 | 2.91 | 3.66 | |
| 120 | 1.14 | 2.18 | 3.05 | 3.82 | |
| W14 × 53 | 80 | 0.91 | 1.81 | 2.58 | 3.27 |
| 100 | 1.07 | 2.05 | 2.88 | 3.62 | |
| 110 | 1.15 | 2.17 | 3.02 | 3.78 | |
| 120 | 1.22 | 2.28 | 3.16 | 3.94 | |
| W14 × 43 | 80 | 1.01 | 1.93 | 2.71 | 3.41 |
| 100 | 1.17 | 2.17 | 3.00 | 3.74 | |
| 110 | 1.25 | 2.28 | 3.14 | 3.90 | |
| 120 | 1.32 | 2.38 | 3.27 | 4.05 | |
| W12 × 72 | 80 | 0.81 | 1.66 | 2.41 | 3.09 |
| 100 | 0.91 | 1.88 | 2.70 | 3.43 | |
| 110 | 0.99 | 1.99 | 2.84 | 3.60 | |
| 120 | 1.06 | 2.10 | 2.98 | 3.76 | |
| W12 × 58 | 80 | 0.88 | 1.76 | 2.52 | 3.21 |
| 100 | 1.04 | 2.01 | 2.83 | 3.56 | |
| 110 | 1.11 | 2.12 | 2.97 | 3.73 | |
| 120 | 1.19 | 2.23 | 3.11 | 3.89 | |
| W12 × 50 | 80 | 0.91 | 1.81 | 2.58 | 3.27 |
| 100 | 1.07 | 2.05 | 2.88 | 3.62 | |
| 110 | 1.15 | 2.17 | 3.02 | 3.78 | |
| 120 | 1.22 | 2.28 | 3.16 | 3.94 | |
| W12 × 40 | 80 | 1.01 | 1.94 | 2.72 | 3.41 |
| 100 | 1.17 | 2.17 | 3.01 | 3.75 | |
| 110 | 1.25 | 2.28 | 3.14 | 3.90 | |
| 120 | 1.32 | 2.39 | 3.27 | 4.06 | |
| W10 × 68 | 80 | 0.72 | 1.58 | 2.33 | 3.01 |
| 100 | 0.87 | 1.83 | 2.65 | 3.38 | |
| 110 | 0.94 | 1.95 | 2.79 | 3.55 | |
| 120 | 1.01 | 2.06 | 2.94 | 3.72 | |
| W10 × 54 | 80 | 0.88 | 1.76 | 2.53 | 3.21 |
| 100 | 1.04 | 2.01 | 2.83 | 3.57 | |
| 110 | 1.11 | 2.12 | 2.98 | 3.73 | |
| 120 | 1.19 | 2.24 | 3.12 | 3.90 | |
| W10 × 45 | 80 | 0.92 | 1.83 | 2.60 | 3.30 |
| 100 | 1.08 | 2.07 | 2.90 | 3.64 | |
| 110 | 1.16 | 2.18 | 3.04 | 3.80 | |
| 120 | 1.23 | 2.29 | 3.18 | 3.96 | |
| W10 × 33 | 80 | 1.06 | 2.00 | 2.79 | 3.49 |
| 100 | 1.22 | 2.23 | 3.07 | 3.80 | |
| 110 | 1.30 | 2.34 | 3.20 | 3.96 | |
| 120 | 1.37 | 2.44 | 3.33 | 4.12 | |
| W8 × 40 | 80 | 0.94 | 1.85 | 2.63 | 3.33 |
| 100 | 1.10 | 2.10 | 2.93 | 3.67 | |
| 110 | 1.18 | 2.21 | 3.07 | 3.83 | |
| 120 | 1.25 | 2.32 | 3.20 | 3.99 | |
| W8 × 31 | 80 | 1.06 | 2.00 | 2.78 | 3.49 |
| 100 | 1.22 | 2.23 | 3.07 | 3.81 | |
| 110 | 1.29 | 2.33 | 3.20 | 3.97 | |
| 120 | 1.36 | 2.44 | 3.33 | 4.12 | |
| W8 × 24 | 80 | 1.14 | 2.09 | 2.89 | 3.59 |
| 100 | 1.29 | 2.31 | 3.16 | 3.90 | |
| 110 | 1.36 | 2.42 | 3.28 | 4.05 | |
| 120 | 1.43 | 2.52 | 3.41 | 4.20 | |
| W8 × 18 | 80 | 1.22 | 2.20 | 3.01 | 3.72 |
| 100 | 1.36 | 2.40 | 3.25 | 4.01 | |
| 110 | 1.42 | 2.50 | 3.37 | 4.14 | |
| 120 | 1.48 | 2.59 | 3.49 | 4.28 | |
| 8 × 8 × 1/2 wall thickness | 80 | 0.77 | 1.66 | 2.44 | 3.13 |
| 100 | 0.92 | 1.91 | 2.75 | 3.49 | |
| 110 | 1.00 | 2.02 | 2.89 | 3.66 | |
| 120 | 1.07 | 2.14 | 3.03 | 3.82 | |
| 8 × 8 × 3/8 wall thickness | 80 | 0.91 | 1.84 | 2.63 | 3.33 |
| 100 | 1.07 | 2.08 | 2.92 | 3.67 | |
| 110 | 1.14 | 2.19 | 3.06 | 3.83 | |
| 120 | 1.21 | 2.29 | 3.19 | 3.98 | |
| 8 × 8 × 1/4 wall thickness | 80 | 1.10 | 2.06 | 2.86 | 3.57 |
| 100 | 1.25 | 2.28 | 3.13 | 3.87 | |
| 110 | 1.32 | 2.38 | 3.25 | 4.02 | |
| 120 | 1.39 | 2.48 | 3.38 | 4.17 | |
| 6 × 6 × 1/2 wall thickness | 80 | 0.82 | 1.75 | 2.54 | 3.25 |
| 100 | 0.98 | 1.99 | 2.84 | 3.59 | |
| 110 | 1.05 | 2.10 | 2.98 | 3.75 | |
| 120 | 1.12 | 2.21 | 3.11 | 3.91 | |
| 6 × 6 × 3/8 wall thickness | 80 | 0.96 | 1.91 | 2.71 | 3.42 |
| 100 | 1.12 | 2.14 | 3.00 | 3.75 | |
| 110 | 1.19 | 2.25 | 3.13 | 3.90 | |
| 120 | 1.26 | 2.35 | 3.26 | 4.05 | |
| 6 × 6 × 1/4 wall thickness | 80 | 1.14 | 2.11 | 2.92 | 3.63 |
| 100 | 1.29 | 2.32 | 3.18 | 3.93 | |
| 110 | 1.36 | 2.43 | 3.30 | 4.08 | |
| 120 | 1.42 | 2.52 | 3.43 | 4.22 | |
| 4 × 4 × 1/2 wall thickness | 80 | 0.93 | 1.90 | 2.71 | 3.43 |
| 100 | 1.08 | 2.13 | 2.99 | 3.76 | |
| 110 | 1.16 | 2.24 | 3.13 | 3.91 | |
| 120 | 1.22 | 2.34 | 3.26 | 4.06 | |
| 4 × 4 × 3/8 wall thickness | 80 | 1.05 | 2.03 | 2.84 | 3.57 |
| 100 | 1.20 | 2.25 | 3.11 | 3.88 | |
| 110 | 1.27 | 2.35 | 3.24 | 4.02 | |
| 120 | 1.34 | 2.45 | 3.37 | 4.17 | |
| 4 × 4 × 1/4 wall thickness | 80 | 1.21 | 2.20 | 3.01 | 3.73 |
| 100 | 1.35 | 2.40 | 3.26 | 4.02 | |
| 110 | 1.41 | 2.50 | 3.38 | 4.16 | |
| 120 | 1.48 | 2.59 | 3.50 | 4.30 | |
| 6 double extra strong 0.864 wall thickness | 80 | 0.59 | 1.46 | 2.23 | 2.92 |
| 100 | 0.73 | 1.71 | 2.54 | 3.29 | |
| 110 | 0.80 | 1.82 | 2.69 | 3.47 | |
| 120 | 0.86 | 1.93 | 2.83 | 3.63 | |
| 6 extra strong 0.432 wall thickness | 80 | 0.94 | 1.90 | 2.70 | 3.42 |
| 100 | 1.10 | 2.13 | 2.98 | 3.74 | |
| 110 | 1.17 | 2.22 | 3.11 | 3.89 | |
| 120 | 1.24 | 2.34 | 3.24 | 4.04 | |
| 6 standard 0.280 wall thickness | 80 | 1.14 | 2.12 | 2.93 | 3.64 |
| 100 | 1.29 | 2.33 | 3.19 | 3.94 | |
| 110 | 1.36 | 2.43 | 3.31 | 4.08 | |
| 120 | 1.42 | 2.53 | 3.43 | 4.22 | |
| 5 double extra strong 0.750 wall thickness | 80 | 0.70 | 1.61 | 2.40 | 3.12 |
| 100 | 0.85 | 1.86 | 2.71 | 3.47 | |
| 110 | 0.91 | 1.97 | 2.85 | 3.63 | |
| 120 | 0.98 | 2.02 | 2.99 | 3.79 | |
| 5 extra strong 0.375 wall thickness | 80 | 1.04 | 2.01 | 2.83 | 3.54 |
| 100 | 1.19 | 2.23 | 3.09 | 3.85 | |
| 110 | 1.26 | 2.34 | 3.22 | 4.00 | |
| 20 | 1.32 | 2.44 | 3.34 | 4.14 | |
| 5 standard 0.258 wall thickness | 80 | 1.20 | 2.19 | 3.00 | 3.72 |
| 100 | 1.34 | 2.39 | 3.25 | 4.00 | |
| 110 | 1.41 | 2.49 | 3.37 | 4.14 | |
| 120 | 1.47 | 2.58 | 3.49 | 4.28 | |
| 4 double extra strong 0.674 wall thickness | 80 | 0.80 | 1.75 | 2.56 | 3.28 |
| 100 | 0.95 | 1.99 | 2.85 | 3.62 | |
| 110 | 1.02 | 2.10 | 2.99 | 3.78 | |
| 120 | 1.09 | 2.20 | 3.12 | 3.93 | |
| 4 extra strong 0.337 wall thickness | 80 | 1.12 | 2.11 | 2.93 | 3.65 |
| 100 | 1.26 | 2.32 | 3.19 | 3.95 | |
| 110 | 1.33 | 2.42 | 3.31 | 4.09 | |
| 120 | 1.40 | 2.52 | 3.43 | 4.23 | |
| 4 standard 0.237 wall thickness | 80 | 1.26 | 2.25 | 3.07 | 3.79 |
| 100 | 1.40 | 2.45 | 3.31 | 4.07 | |
| 110 | 1.46 | 2.55 | 3.43 | 4.21 | |
| 120 | 1.53 | 2.64 | 3.54 | 4.34 | |
For SI: 1 inch = 25.4 mm, 1 pound per cubic feet = 16.02 kg/m3.
Note: Tabulated values assume 1-inch air gap between masonry and steel section.
FIGURE 722.5.1(5)
WIDE FLANGE STRUCTURAL STEEL COLUMNS WITH SPRAYED FIRE-RESISTANT MATERIALS
TABLE 722.5.1(6)
FIRE RESISTANCE OF CLAY MASONRY PROTECTED STEEL COLUMNS
| COLUMN SIZE | CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT | MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY, Te (inches) | COLUMN SIZE | CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT | MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY,Te (inches) | ||||||
| 1 hour | 2 hours | 3 hours | 4 hours | 1 hour | 2 hours | 3 hours | 4 hours | ||||
| W14 × 82 | 120 | 1.23 | 2.42 | 3.41 | 4.29 | W10 × 68 | 120 | 1.27 | 2.46 | 3.26 | 4.35 |
| 130 | 1.40 | 2.70 | 3.78 | 4.74 | 130 | 1.44 | 2.75 | 3.83 | 4.80 | ||
| W14 × 68 | 120 | 1.34 | 2.54 | 3.54 | 4.43 | W10 × 54 | 120 | 1.40 | 2.61 | 3.62 | 4.51 |
| 130 | 1.51 | 2.82 | 3.91 | 4.87 | 130 | 1.58 | 2.89 | 3.98 | 4.95 | ||
| W14 × 53 | 120 | 1.43 | 2.65 | 3.65 | 4.54 | W10 × 45 | 120 | 1.44 | 2.66 | 3.67 | 4.57 |
| 130 | 1.61 | 2.93 | 4.02 | 4.98 | 130 | 1.62 | 2.95 | 4.04 | 5.01 | ||
| W14 × 43 | 120 | 1.54 | 2.76 | 3.77 | 4.66 | W10 × 33 | 120 | 1.59 | 2.82 | 3.84 | 4.73 |
| 130 | 1.72 | 3.04 | 4.13 | 5.09 | 130 | 1.77 | 3.10 | 4.20 | 5.13 | ||
| W12 × 72 | 120 | 1.32 | 2.52 | 3.51 | 4.40 | W8 × 40 | 120 | 1.47 | 2.70 | 3.71 | 4.61 |
| 130 | 1.50 | 2.80 | 3.88 | 4.84 | 130 | 1.65 | 2.98 | 4.08 | 5.04 | ||
| W12 × 58 | 120 | 1.40 | 2.61 | 3.61 | 4.50 | W8 × 31 | 120 | 1.59 | 2.82 | 3.84 | 4.73 |
| 130 | 1.57 | 2.89 | 3.98 | 4.94 | 130 | 1.77 | 3.10 | 4.20 | 5.17 | ||
| W12 × 50 | 120 | 1.43 | 2.65 | 3.66 | 4.55 | W8 × 24 | 120 | 1.66 | 2.90 | 3.92 | 4.82 |
| 130 | 1.61 | 2.93 | 4.02 | 4.99 | 130 | 1.84 | 3.18 | 4.28 | 5.25 | ||
| W12 × 40 | 120 | 1.54 | 2.77 | 3.78 | 4.67 | W8 × 18 | 120 | 1.75 | 3.00 | 4.01 | 4.91 |
| 130 | 1.72 | 3.05 | 4.14 | 5.10 | 130 | 1.93 | 3.27 | 4.37 | 5.34 | ||
| STEEL TUBING | STEEL PIPE | ||||||||||
| NOMINAL TUBE SIZE (inches) | CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT | MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY, Te (inches) | NOMINAL PIPE SIZE (inches) | CLAY MASONRY DENSITY, POUNDS PER CUBIC FOOT | MINIMUM REQUIRED EQUIVALENT THICKNESS FOR FIRE-RESISTANCE RATING OF CLAY MASONRY PROTECTION ASSEMBLY, Te (inches) | ||||||
| 1 hour | 2 hours | 3 hours | 4 hours | 1 hour | 2 hours | 3 hours | 4 hours | ||||
| 4 × 4 × 1/2 wall thickness | 120 | 1.44 | 2.72 | 3.76 | 4.68 | 4 double extra strong 0.674 wall thickness | 120 | 1.26 | 2.55 | 3.60 | 4.52 |
| 130 | 1.62 | 3.00 | 4.12 | 5.11 | 130 | 1.42 | 2.82 | 3.96 | 4.95 | ||
| 4 × 4 × 3/8 wall thickness | 120 | 1.56 | 2.84 | 3.88 | 4.78 | 4 extra strong 0.337 wall thickness | 120 | 1.60 | 2.89 | 3.92 | 4.83 |
| 130 | 1.74 | 3.12 | 4.23 | 5.21 | 130 | 1.77 | 3.16 | 4.28 | 5.25 | ||
| 4 × 4 × 1/4 wall thickness | 120 | 1.72 | 2.99 | 4.02 | 4.92 | 4 standard 0.237 wall thickness | 120 | 1.74 | 3.02 | 4.05 | 4.95 |
| 130 | 1.89 | 3.26 | 4.37 | 5.34 | 130 | 1.92 | 3.29 | 4.40 | 5.37 | ||
| 6 × 6 × 1/2 wall thickness | 120 | 1.33 | 2.58 | 3.62 | 4.52 | 5 double extra strong 0.750 wall thickness | 120 | 1.17 | 2.44 | 3.48 | 4.40 |
| 130 | 1.50 | 2.86 | 3.98 | 4.96 | 130 | 1.33 | 2.72 | 3.84 | 4.83 | ||
| 6 × 6 × 3/8 wall thickness | 120 | 1.48 | 2.74 | 3.76 | 4.67 | 5 extra strong 0.375 wall thickness | 120 | 1.55 | 2.82 | 3.85 | 4.76 |
| 130 | 1.65 | 3.01 | 4.13 | 5.10 | 130 | 1.72 | 3.09 | 4.21 | 5.18 | ||
| 6 × 6 × 1/4 wall thickness | 120 | 1.66 | 2.91 | 3.94 | 4.84 | 5 standard 0.258 wall thickness | 120 | 1.71 | 2.97 | 4.00 | 4.90 |
| 130 | 1.83 | 3.19 | 4.30 | 5.27 | 130 | 1.88 | 3.24 | 4.35 | 5.32 | ||
| 8 × 8 × 1/2 wall thickness | 120 | 1.27 | 2.50 | 3.52 | 4.42 | 6 double extra strong 0.864 wall thickness | 120 | 1.04 | 2.28 | 3.32 | 4.23 |
| 130 | 1.44 | 2.78 | 3.89 | 4.86 | 130 | 1.19 | 2.60 | 3.68 | 4.67 | ||
| 8 × 8 × 3/8 wall thickness | 120 | 1.43 | 2.67 | 3.69 | 4.59 | 6 extra strong 0.432 wall thickness | 120 | 1.45 | 2.71 | 3.75 | 4.65 |
| 130 | 1.60 | 2.95 | 4.05 | 5.02 | 130 | 1.62 | 2.99 | 4.10 | 5.08 | ||
| 8 × 8 × 1/4 wall thickness | 120 | 1.62 | 2.87 | 3.89 | 4.78 | 6 standard 0.280 wall thickness | 120 | 1.65 | 2.91 | 3.94 | 4.84 |
| 130 | 1.79 | 3.14 | 4.24 | 5.21 | 130 | 1.82 | 3.19 | 4.30 | 5.27 | ||
For SI: 1 inch = 25.4 mm, 1 pound per cubic foot = 16.02 kg/m3.
a.Where the inside perimeter of the concrete protection is not square, L shall be taken as the average of L1 and L2. Where the thickness of concrete cover is not constant, h shall be taken of the average of h1 and h2.
b.Joints shall be protected with not less than a 1-inch thickness of ceramic fiber blanket but in no case less than one-half the thickness of the column cover (see Section 722.2.1.3).
FIGURE 722.5.1(6)
CONCRETE PROTECTED STRUCTURAL STEEL COLUMNSa, b
TABLE 722.5.1(7)
MINIMUM COVER (inch) FOR STEEL COLUMNS ENCASED IN NORMAL-WEIGHT CONCRETEa[Figure 722.5.1(6)(c)]
| STRUCTURAL SHAPE | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |
| W14 × 233 | 1 | 1 | 1 | 11/2 | 2 |
| × 176 | 21/2 | ||||
| × 132 | 2 | ||||
| × 90 | 11/2 | ||||
| × 61 | 3 | ||||
| × 48 | 11/2 | 21/2 | |||
| × 43 | |||||
| W12 × 152 | 1 | 1 | 1 | 2 | 21/2 |
| × 96 | |||||
| × 65 | 11/2 | 11/2 | 3 | ||
| × 50 | 21/2 | ||||
| × 40 | |||||
| W10 × 88 | 1 | 11/2 | 11/2 | 2 | 3 |
| × 49 | 1 | 21/2 | |||
| × 45 | |||||
| × 39 | 31/2 | ||||
| × 33 | 2 | ||||
| W8 × 67 | 1 | 1 | 11/2 | 21/2 | 3 |
| × 58 | |||||
| × 48 | 11/2 | 31/2 | |||
| × 31 | 2 | 3 | |||
| × 21 | |||||
| × l8 | 4 | ||||
| W6 × 25 | 1 | 11/2 | 2 | 3 | 31/2 |
| × 20 | 2 | 21/2 | 4 | ||
| × 16 | 31/2 | ||||
| × 15 | 11/2 | ||||
| × 9 | |||||
FIGURE 722.5.1(7)
CONCRETE OR CLAY MASONRY PROTECTED STRUCTURAL STEEL COLUMNS
TABLE 722.5.1(8)
MINIMUM COVER (inch) FOR STEEL COLUMNS ENCASED IN STRUCTURAL LIGHTWEIGHT CONCRETEa[FIGURE 722.5.1(6)(c)]
| STRUCTURAL SHAPE | FIRE-RESISTANCE RATING (HOURS) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |
| W14 × 233 | 1 | 1 | 1 | 1 | 11/2 |
| × 193 | 11/2 | ||||
| × 74 | 2 | ||||
| × 61 | 21/2 | ||||
| × 43 | 11/2 | 2 | |||
| W12 × 65 | 1 | 1 | 1 | 11/2 | 2 |
| × 53 | 2 | 21/2 | |||
| × 40 | 11/2 | ||||
| W10 × 112 | 1 | 1 | 1 | 11/2 | 2 |
| × 88 | |||||
| × 60 | 2 | 21/2 | |||
| × 33 | 11/2 | ||||
| W8 × 35 | 1 | 1 | 11/2 | 2 | 21/2 |
| × 28 | 3 | ||||
| × 24 | 21/2 | ||||
| × 18 | 11/2 | ||||
TABLE 722.5.1(9)
MINIMUM COVER (inch) FOR STEEL COLUMNS IN NORMAL-WEIGHT PRECAST COVERSa[FIGURE 722.5.1 (6)(a)]
| STRUCTURAL SHAPE | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |
| W14 × 233 | 11/2 | 11/2 | 11/2 | 21/2 | 3 |
| × 211 | 31/2 | ||||
| × 176 | 2 | ||||
| × 145 | 3 | ||||
| × 109 | 2 | 21/2 | |||
| × 99 | 4 | ||||
| × 61 | 31/2 | ||||
| × 43 | 41/2 | ||||
| W12 × 190 | 11/2 | 11/2 | 11/2 | 21/2 | 31/2 |
| × 152 | 2 | ||||
| × 120 | 3 | 4 | |||
| × 96 | |||||
| × 87 | 2 | 21/2 | 31/2 | ||
| × 58 | 41/2 | ||||
| × 40 | |||||
| W10 × 112 | 11/2 | 11/2 | 2 | 3 | 31/2 |
| × 88 | 4 | ||||
| × 77 | 2 | 21/2 | |||
| × 54 | 31/2 | ||||
| × 33 | 41/2 | ||||
| W8 × 67 | 11/2 | 11/2 | 2 | 3 | 4 |
| × 58 | 2 | 21/2 | 31/2 | ||
| × 48 | |||||
| × 28 | 41/2 | ||||
| × 21 | 21/2 | 3 | |||
| × 18 | 4 | ||||
| W6 × 25 | 11/2 | 2 | 21/2 | 31/2 | 41/2 |
| × 20 | 21/2 | 3 | |||
| × 16 | 4 | ||||
| × 12 | 2 | ||||
| × 9 | 5 | ||||
TABLE 722.5.1(10)
MINIMUM COVER (inch) FOR STEEL COLUMNS IN STRUCTURAL LIGHTWEIGHT PRECAST COVERSa[FIGURE 722.5.1 (6)(a)]
| STRUCTURAL SHAPE | FIRE-RESISTANCE RATING (hours) | ||||
| 1 | 11/2 | 2 | 3 | 4 | |
| W14 × 233 | 11/2 | 11/2 | 11/2 | 2 | 21/2 |
| × 176 | 3 | ||||
| × 145 | 21/2 | ||||
| × 132 | |||||
| × 109 | |||||
| × 99 | 2 | ||||
| × 68 | 31/2 | ||||
| × 43 | 3 | ||||
| W12 × 190 | 11/2 | 11/2 | 11/2 | 2 | 21/2 |
| × 152 | |||||
| × 136 | 3 | ||||
| × 106 | 21/2 | ||||
| × 96 | 31/2 | ||||
| × 87 | |||||
| × 65 | 2 | ||||
| × 40 | 3 | ||||
| W10 × 112 | 11/2 | 11/2 | 11/2 | 2 | 3 |
| × 100 | 21/2 | ||||
| × 88 | |||||
| × 77 | 2 | 31/2 | |||
| × 60 | |||||
| × 39 | 3 | ||||
| × 33 | 2 | ||||
| W8 × 67 | 11/2 | 11/2 | 11/2 | 21/2 | 3 |
| × 48 | 2 | 3 | 31/2 | ||
| × 35 | |||||
| × 28 | 2 | ||||
| × 18 | 21/2 | 4 | |||
| W6 × 25 | 11/2 | 2 | 2 | 3 | 31/2 |
| × 15 | 21/2 | 4 | |||
| × 9 | 31/2 | ||||
722.5.1.1 General.
722.5.1.1.1 Nonload-bearing protection.
722.5.1.1.2 Embedments.
722.5.1.1.3 Weight-to-perimeter ratio.
722.5.1.2 Gypsum wallboard protection.
The fire resistance of structural steel columns with weight-to-heated-perimeter ratios (W/D) less than or equal to 3.65 and that are protected with Type X gypsum wallboard shall be permitted to be determined from the following expression:
where:
R = Fire resistance (minutes).
h = Total thickness of gypsum wallboard (inches).
D = Heated perimeter of the structural steel column (inches).
W' = Total weight of the structural steel column and gypsum wallboard protection (pounds per linear foot).
W' = W + 50hD/144.
722.5.1.2.2 Gypsum wallboard equivalent to concrete.
722.5.1.3 Sprayed fire-resistant materials.
The fire resistance of wide-flange structural steel columns protected with sprayed fire-resistant materials, as illustrated in Figure 722.5.1(5), shall be permitted to be determined from the following expression:
where:
R = Fire resistance (minutes).
h = Thickness of sprayed fire-resistant material (inches).
D = Heated perimeter of the structural steel column (inches).
C1 and C2 = Material-dependent constants.
W = Weight of structural steel columns (pounds per linear foot).
The fire resistance of structural steel columns protected with intumescent or mastic fire-resistant coatings shall be determined on the basis of fire-resistance tests in accordance with Section 703.2.
722.5.1.3.1 Material-dependent constants.
722.5.1.3.2 Identification.
722.5.1.4 Concrete-protected columns.
The fire resistance of structural steel columns protected with concrete, as illustrated in Figure 722.5.1(6) illustrations (a) and (b), shall be permitted to be determined from the following expression:
where:
As used in these expressions:
R = Fire endurance at equilibrium moisture conditions (minutes).
Ro = Fire endurance at zero moisture content (minutes).
m = Equilibrium moisture content of the concrete by volume (percent).
W = Average weight of the structural steel column (pounds per linear foot).
D = Heated perimeter of the structural steel column (inches).
h = Thickness of the concrete cover (inches).
kc = Ambient temperature thermal conductivity of the concrete (Btu/hr ft °F).
H = Ambient temperature thermal capacity of the steel column = 0.11W (Btu/ ft °F).
pc = Concrete density (pounds per cubic foot).
cc = Ambient temperature specific heat of concrete (Btu/lb °F).
L = Interior dimension of one side of a square concrete box protection (inches).
722.5.1.4.1 Reentrant space filled.
For wide-flange structural steel columns completely encased in concrete with all reentrant spaces filled Figure 722.5.1(6), illustration (c), the thermal capacity of the concrete within the reentrant spaces shall be permitted to be added to the thermal capacity of the steel column, as follows:
where:
bf = Flange width of the structural steel column (inches).
d = Depth of the structural steel column (inches).
As = Cross-sectional area of the steel column (square inches).
722.5.1.4.3 Minimum concrete cover.
722.5.1.4.4 Minimum precast concrete cover.
722.5.1.4.5 Masonry protection.
The fire resistance of structural steel columns protected with concrete masonry units or clay masonry units as illustrated in Figure 722.5.1(7) shall be permitted to be determined from the following expression:
where:
R = Fire-resistance rating of column assembly (hours).
W = Average weight of structural steel column (pounds per foot).
D = Heated perimeter of structural steel column (inches) [see Figure 722.5.1(7)].
Te = Equivalent thickness of concrete or clay masonry unit (inches) (see Table 722.3.2, Note a or Section 722.4.1).
K = Thermal conductivity of concrete or clay masonry unit (Btu/hr × ft × °F) [see Table 722.5.1(3)].
As = Cross-sectional area of structural steel column (square inches).
dm = Density of the concrete or clay masonry unit (pounds per cubic foot).
p = Inner perimeter of concrete or clay masonry protection (inches) [see Figure 722.5.1(7)].
722.5.1.4.6 Equivalent concrete masonry thickness.
722.5.2 Structural steel beams and girders.
FIGURE 722.5.2
DETERMINATION OF THE HEATED PERIMETER OF STRUCTURAL STEEL BEAMS AND GIRDERS
722.5.2.1 Determination of fire resistance.
722.5.2.1.1 Weight-to-heated perimeter.
722.5.2.1.2 Beam and girder substitutions.
722.5.2.2 Sprayed fire-resistant materials.
The provisions in this section apply to structural steel beams and girders protected with sprayed fire-resistant materials. Larger or smaller beam and girder shapes shall be permitted to be substituted for beams specified in approved unrestrained or restrained fire-resistance-rated assemblies, provided that the thickness of the fire-resistant material is adjusted in accordance with the following expression:
where:
h = Thickness of sprayed fire-resistant material in inches.
W = Weight of the structural steel beam or girder in pounds per linear foot.
D = Heated perimeter of the structural steel beam in inches.
Subscript 1 refers to the beam and fire-resistant material thickness in the approved assembly.
Subscript 2 refers to the substitute beam or girder and the required thickness of fire-resistant material.
The fire resistance of structural steel beams and girders protected with intumescent or mastic fire-resistant coatings shall be determined on the basis of fire-resistance tests in accordance with Section 703.2.
722.5.2.2.1 Minimum thickness.
The use of Equation 7-17 is subject to the following conditions:
1.The weight-to-heated-perimeter ratio for the substitute beam or girder (W2/D2) shall be not less than 0.37.
2.The thickness of fire protection materials calculated for the substitute beam or girder (T1) shall be not less than 3/8 inch (9.5 mm).
3.The unrestrained or restrained beam rating shall be not less than 1 hour.
4.Where used to adjust the material thickness for a restrained beam, the use of this procedure is limited to structural steel sections classified as compact in accordance with AISC 360.
722.5.2.3 Structural steel trusses.
The fire resistance of structural steel trusses protected with fire-resistant materials sprayed to each of the individual truss elements shall be permitted to be determined in accordance with this section. The thickness of the fire-resistant material shall be determined in accordance with Section 722.5.1.3. The weight-to-heated-perimeter ratio (W/D) of truss elements that can be simultaneously exposed to fire on all sides shall be determined on the same basis as columns, as specified in Section 722.5.1.1. The weight-to-heated-perimeter ratio (W/D) of truss elements that directly support floor or roof assembly shall be determined on the same basis as beams and girders, as specified in Section 722.5.2.1.
The fire resistance of structural steel trusses protected with intumescent or mastic fire-resistant coatings shall be determined on the basis of fire resistance tests in accordance with Section 703.2.
722.6 Wood assemblies.
722.6.1 General.
722.6.1.2 Dissimilar membranes.
722.6.2 Walls, floors and roofs.
TABLE 722.6.2(1)
TIME ASSIGNED TO WALLBOARD MEMBRANESa, b, c, d
| DESCRIPTION OF FINISH | TIMEe (minutes) |
| 3/8-inch wood structural panel bonded with exterior glue | 5 |
| 15/32-inch wood structural panel bonded with exterior glue | 10 |
| 19/32-inch wood structural panel bonded with exterior glue | 15 |
| 3/8-inch gypsum wallboard | 10 |
| 1/2-inch gypsum wallboard | 15 |
| 5/8-inch gypsum wallboard | 30 |
| 1/2-inch Type X gypsum wallboard | 25 |
| 5/8-inch Type X gypsum wallboard | 40 |
| Double 3/8-inch gypsum wallboard | 25 |
| 1/2-inch + 3/8-inch gypsum wallboard | 35 |
| Double 1/2-inch gypsum wallboard | 40 |
For SI: 1 inch = 25.4 mm.
a.These values apply only where membranes are installed on framing members that are spaced 16 inches o.c. or less.
b.Gypsum wallboard installed over framing or furring shall be installed so that all edges are supported, except 5/8-inch Type X gypsum wallboard shall be permitted to be installed horizontally with the horizontal joints staggered 24 inches each side and unsupported but finished.
c.On wood frame floor/ceiling or roof/ceiling assemblies, gypsum board shall be installed with the long dimension perpendicular to framing members and shall have all joints finished.
d.The membrane on the unexposed side shall not be included in determining the fire resistance of the assembly. Where dissimilar membranes are used on a wall assembly, the calculation shall be made from the least fire-resistant (weaker) side.
e.The time assigned is not a finished rating.
TABLE 722.6.2(2)
TIME ASSIGNED FOR CONTRIBUTION OF WOOD FRAME a, b, c
| DESCRIPTION | TIME ASSIGNED TO FRAME (minutes) |
| Wood studs 16 inches o.c. | 20 |
| Wood floor and roof joists 16 inches o.c. | 10 |
For SI: 1 inch = 25.4 mm.
TABLE 722.6.2(3)
MEMBRANEaON EXTERIOR FACE OF WOOD STUD WALLS
| SHEATHING | PAPER | EXTERIOR FINISH |
| 5/8-inch T & G lumber 5/16-inch exterior glue wood structural panel 1/2-inch gypsum wallboard 5/8-inch gypsum wallboard 1/2-inch fiberboard | Sheathing paper | Lumber siding Wood shingles and shakes 1/4-inch fiber-cement lap, panel or shingle siding 1/4-inch wood structural panels-exterior type 1/4-inch hardboard Metal siding Stucco on metal lath Masonry veneer Vinyl siding |
| None | — | 3/8-inch exterior-grade wood structural panels |
For SI: 1 inch = 25.4 mm.
a. Any combination of sheathing, paper and exterior finish is permitted.
TABLE 722.6.2(4)
FLOORING OR ROOFING OVER WOOD FRAMINGa
| ASSEMBLY | STRUCTURAL MEMBERS | SUBFLOOR OR ROOF DECK | FINISHED FLOORING OR ROOFING |
| Floor | Wood | 15/32-inch wood structural panels or 11/16-inch T & G softwood | Hardwood or softwood flooring on building paper; resilient flooring; parquet floor; felted-synthetic fiber floor coverings, carpeting, or ceramic tile on 1/4-inch-thick fiber-cement underlayment or 3/8-inch-thick panel-type underlayment; ceramic tile on 11/4-inch mortar bed. |
| Roof | Wood | 15/32-inch wood structural panels or 11/16-inch T & G softwood | Finished roofing material with or without insulation |
For SI: 1 inch = 25.4 mm.
a.This table applies only to wood joist construction. It is not applicable to wood truss construction.
TABLE 722.6.2(5)
TIME ASSIGNED FOR ADDITIONAL PROTECTION
| DESCRIPTION OF ADDITIONAL PROTECTION | FIRE RESISTANCE (minutes) |
| Add to the fire-resistance rating of wood stud walls if the spaces between the studs are completely filled with glass fiber mineral wool batts weighing not less than 2 pounds per cubic foot (0.6 pound per square foot of wall surface) or rockwool or slag material wool batts weighing not less than 3.3 pounds per cubic foot (1 pound per square foot of wall surface), or cellulose insulation having a nominal density not less than 2.6 pounds per cubic foot. | 15 |
For SI: 1 pound/cubic foot = 16.0185 kg/m3.
722.6.2.1 Fire-resistance rating of wood frame assemblies.
722.6.2.3 Exterior walls.
722.6.2.4 Floors and roofs.
722.7 Fire-resistance rating for mass timber.
722.7.1 Minimum required protection.
TABLE 722.7.1(2)
PROTECTION PROVIDED BY NONCOMBUSTIBLE COVERING MATERIAL
| NONCOMBUSTIBLE PROTECTION | PROTECTION CONTRIBUTION (minutes) |
| 1/2-inch Type X gypsum board | 25 |
| 5/8-inch Type X gypsum board | 40 |
722.7.2 Installation of gypsum board noncombustible protection.
722.7.2.1 Interior surfaces.
1.Each layer shall be attached with Type S drywall screws of sufficient length to penetrate the mass timber at least 1 inch (25 mm) when driven flush with the paper surface of the gypsum board.
2.Screws for attaching the base layer shall be 12 inches (305 mm) on center in both directions.
3.Screws for each layer after the base layer shall be 12 inches (305 mm) on center in both directions and offset from the screws of the previous layers by 4 inches (102 mm) in both directions.
4.All panel edges of any layer shall be offset 18 inches (457 mm) from those of the previous layer.
5.All panel edges shall be attached with screws sized and offset as in Items 1 through 4 and placed at least 1 inch (25 mm) but not more than 2 inches (51 mm) from the panel edge.
6.All panels installed at wall-to-ceiling intersections shall be installed such that ceiling panels are installed first and the wall panels are installed after the ceiling panel has been installed and is fitted tight to the ceiling panel. Where multiple layers are required, each layer shall repeat this process.
7.All panels installed at a wall-to-wall intersection shall be installed such that the panels covering an exterior wall or a wall with a greater fire-resistance rating shall be installed first and the panels covering the other wall shall be fitted tight to the panel covering the first wall. Where multiple layers are required, each layer shall repeat this process.
8.Panel edges of the face layer shall be taped and finished with joint compound. Fastener heads shall be covered with joint compound.
9.Panel edges protecting mass timber elements adjacent to unprotected mass timber elements in accordance with Section 602.4.2.2 shall be covered with 11/4-inch (32 mm) metal corner bead and finished with joint compound.