Appendix B Fire-Flow Requirements for Buildings

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APPENDIXB
FIRE-FLOW REQUIREMENTS FOR BUILDINGS

The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance.

SECTION B101
GENERAL

B101.1 Scope.

The procedure for determining fire-flow requirements for buildings or portions of buildings hereafter constructed shall be in accordance with this appendix. This appendix does not apply to structures other than buildings.

SECTION B102
DEFINITIONS

B102.1 Definitions.

For the purpose of this appendix, certain terms are defined as follows:

FIRE-FLOW. The flow rate of a water supply, measured at 20 pounds per square inch (psi) (138 kPa) residual pressure, that is available for fire fighting.

FIRE-FLOW CALCULATION AREA. The floor area, in square feet (m2), used to determine the required fire flow.

SECTION B103
MODIFICATIONS

B103.1 Decreases.

The fire chief is authorized to reduce the fire-flow requirements for isolated buildings or a group of buildings in rural areas or small communities where the development of full fire-flow requirements is impractical.

B103.2 Increases.

The fire chief is authorized to increase the fire-flow requirements where conditions indicate an unusual susceptibility to group fires or conflagrations. An increase shall not be more than twice that required for the building under consideration.

B103.3 Areas without water supply systems.

For information regarding water supplies for fire-fighting purposes in rural and suburban areas in which adequate and reliable water supply systems do not exist, the fire code official is authorized to utilize NFPA 1142 or the International Wildland-Urban Interface Code.

SECTION B104
FIRE-FLOW CALCULATION AREA

B104.1 General.

The fire-flow calculation area shall be the total floor area of all floor levels within the exterior walls, and under the horizontal projections of the roof of a building, except as modified in Section B104.3.

B104.2 Area separation.

Portions of buildings which are separated by fire walls without openings, constructed in accordance with the International Building Code, are allowed to be considered as separate fire-flow calculation areas.

B104.3 Type IA and Type IB construction.

The fire-flow calculation area of buildings constructed of Type IA and Type IB construction shall be the area of the three largest successive floors.

Exception: Fire-flow calculation area for open parking garages shall be determined by the area of the largest floor.

SECTION B105
FIRE-FLOW REQUIREMENTS FOR BUILDINGS

B105.1 One- and two-family dwellings, Group R-3 and R-4 buildings and townhouses.

The minimum fire-flow and flow duration requirements for one- and two-family dwellings, Group R-3 and R-4 buildings and townhouses shall be as specified in Tables B105.1(1) and B105.1(2).

TABLE B105.1(1)

REQUIRED FIRE-FLOW FOR ONE- AND TWO-FAMILY DWELLINGS, GROUP R-3 AND R-4 BUILDINGS AND TOWNHOUSES

FIRE-FLOW CALCULATION AREA (square feet) AUTOMATIC SPRINKLER SYSTEM (Design Standard) MINIMUM FIRE-FLOW (gallons per minute) FLOW DURATION (hours)
0-3,600 No automatic sprinkler system 1,000 1
3,601 and greater No automatic sprinkler system Value in Table B105.1(2) Duration in Table B105.1(2) at the required fire-flow rate
0-3,600 Section 903.3.1.3 of the International Fire Code orSection P2904 of the International Residential Code 500 1/2
3,601 and greater Section 903.3.1.3 of the International Fire Code orSection P2904 of the International Residential Code 1/2 value in Table B105.1(2) 1

For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m.

TABLE B105.1(2)

REFERENCE TABLE FOR TABLES B105.1(1) AND B105.2

FIRE-FLOW CALCULATION AREA (square feet) FIRE-FLOW (gallons per minute)b FLOW DURATION (hours)
Type IA and IBa Type IIA and IIIAa Type IV and V-Aa Type IIB and IIIBa Type V-Ba
0-22,700 0-12,700 0-8,200 0-5,900 0-3,600 1,500 2
22,701-30,200 12,701-17,000 8,201-10,900 5,901-7,900 3,601-4,800 1,750
30,201-38,700 17,001-21,800 10,901-12,900 7,901-9,800 4,801-6,200 2,000
38,701-48,300 21,801-24,200 12,901-17,400 9,801-12,600 6,201-7,700 2,250
48,301-59,000 24,201-33,200 17,401-21,300 12,601-15,400 7,701-9,400 2,500
59,001-70,900 33,201-39,700 21,301-25,500 15,401-18,400 9,401-11,300 2,750
70,901-83,700 39,701-47,100 25,501-30,100 18,401-21,800 11,301-13,400 3,000 3
83,701-97,700 47,101-54,900 30,101-35,200 21,801-25,900 13,401-15,600 3,250
97,701-112,700 54,901-63,400 35,201-40,600 25,901-29,300 15,601-18,000 3,500
112,701-128,700 63,401-72,400 40,601-46,400 29,301-33,500 18,001-20,600 3,750
128,701-145,900 72,401-82,100 46,401-52,500 33,501-37,900 20,601-23,300 4,000 4
145,901-164,200 82,101-92,400 52,501-59,100 37,901-42,700 23,301-26,300 4,250
164,201-183,400 92,401-103,100 59,101-66,000 42,701-47,700 26,301-29,300 4,500
183,401-203,700 103,101-114,600 66,001-73,300 47,701-53,000 29,301-32,600 4,750
203,701-225,200 114,601-126,700 73,301-81,100 53,001-58,600 32,601-36,000 5,000
225,201-247,700 126,701-139,400 81,101-89,200 58,601-65,400 36,001-39,600 5,250
247,701-271,200 139,401-152,600 89,201-97,700 65,401-70,600 39,601-43,400 5,500
271,201-295,900 152,601-166,500 97,701-106,500 70,601-77,000 43,401-47,400 5,750
295,901-Greater 166,501-Greater 106,501-115,800 77,001-83,700 47,401-51,500 6,000
115,801-125,500 83,701-90,600 51,501-55,700 6,250
125,501-135,500 90,601-97,900 55,701-60,200 6,500
135,501-145,800 97,901-106,800 60,201-64,800 6,750
145,801-156,700 106,801-113,200 64,801-69,600 7,000
156,701-167,900 113,201-121,300 69,601-74,600 7,250
167,901-179,400 121,301-129,600 74,601-79,800 7,500
179,401-191,400 129,601-138,300 79,801-85,100 7,750
191,401-Greater 138,301-Greater 85,101-Greater 8,000

For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m, 1 pound per square inch = 6.895 kPa.

  1. a.Types of construction are based on the International Building Code.

  2. b.Measured at 20 psi residual pressure.

B105.2 Buildings other than one- and two-family dwellings, Group R-3 and R-4 buildings and townhouses.

The minimum fire-flow and flow duration for buildings other than one- and two-family dwellings, Group R-3 and R-4 buildings and townhouses shall be as specified in Tables B105.2 and B105.1(2).

TABLE B105.2

REQUIRED FIRE-FLOW FOR BUILDINGS OTHER THAN ONE- AND TWO-FAMILY DWELLINGS, GROUP R-3 AND R-4 BUILDINGS AND TOWNHOUSES

AUTOMATIC SPRINKLER SYSTEM(Design Standard) MINIMUM FIRE-FLOW(gallons per minute) FLOW DURATION (hours)
No automatic sprinkler system Value in Table B105.1(2) Duration in Table B105.1(2)
Section 903.3.1.1 of the International Fire Code 25% of the value in Table B105.1(2)a Duration in Table B105.1(2) at the reduced flow rate
Section 903.3.1.2 of the International Fire Code 25% of the value in Table B105.1(2)b Duration in Table B105.1(2) at the reduced flow rate

For SI: 1 gallon per minute = 3.785 L/m.

  1. a.The reduced fire-flow shall be not less than 1,000 gallons per minute.

  2. b.The reduced fire-flow shall be not less than 1,500 gallons per minute.

B105.3 Water supply for buildings equipped with an automatic sprinkler system.

For buildings equipped with an approved automatic sprinkler system, the water supply shall be capable of providing the greater of:

  1. 1.The automatic sprinkler system demand, including hose stream allowance.

  2. 2.The required fire-flow.

SECTION B106
REFERENCED STANDARDS

ICC IBC—15

International Building Code

B104.2,

ICC IFC—15

International Fire Code

Tables B105.1(1) and B105.2

ICC IWUIC—15

International Wildland-Urban Interface Code

B103.3

ICC IRC—15

International Residential Code

Table B105.1(1)

NFPA 1142—12

Standard on Water Supplies for Suburban and Rural Fire Fighting

B103.3