APPENDIXB
FIRE-FLOW REQUIREMENTS FOR BUILDINGS
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
B104.3 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).
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TABLE B105.1(1)
REQUIRED FIRE-FLOW FOR ONE- AND TWO-FAMILY DWELLINGS, GROUP R-3 AND R-4 BUILDINGS AND TOWNHOUSES
For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m.
TABLE B105.1(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 |
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).
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TABLE B105.2
REQUIRED FIRE-FLOW FOR BUILDINGS OTHER THAN ONE- AND TWO-FAMILY DWELLINGS, GROUP R-3 AND R-4 BUILDINGS AND TOWNHOUSES
For SI: 1 gallon per minute = 3.785 L/m.
a.The reduced fire-flow shall be not less than 1,000 gallons per minute.
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.The automatic sprinkler system demand, including hose stream allowance.
2.The required fire-flow.