• APPENDIXB
    FIRE-FLOW REQUIREMENTS FOR BUILDINGS

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

    SECTIONB101
    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.

    SECTIONB102
    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.

    SECTIONB103
    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.

    SECTIONB104
    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.

    SECTIONB105
    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)
    0-3,600No automatic sprinkler system1,0001
    3,601 and greaterNo automatic sprinkler systemValue in Table B105.1(2)Duration in Table B105.1(2) at the required fire-flow rate
    0-3,600Section 903.3.1.3 of the International Fire Code orSection P2904 of the International Residential Code5001/2
    3,601 and greaterSection 903.3.1.3 of the International Fire Code orSection P2904 of the International Residential Code1/2 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)bFLOW DURATION (hours)
    Type IA and IBaType IIA and IIIAaType IV and V-AaType IIB and IIIBaType V-Ba
    0-22,7000-12,7000-8,2000-5,9000-3,6001,5002
    22,701-30,20012,701-17,0008,201-10,9005,901-7,9003,601-4,8001,750
    30,201-38,70017,001-21,80010,901-12,9007,901-9,8004,801-6,2002,000
    38,701-48,30021,801-24,20012,901-17,4009,801-12,6006,201-7,7002,250
    48,301-59,00024,201-33,20017,401-21,30012,601-15,4007,701-9,4002,500
    59,001-70,90033,201-39,70021,301-25,50015,401-18,4009,401-11,3002,750
    70,901-83,70039,701-47,10025,501-30,10018,401-21,80011,301-13,4003,0003
    83,701-97,70047,101-54,90030,101-35,20021,801-25,90013,401-15,6003,250
    97,701-112,70054,901-63,40035,201-40,60025,901-29,30015,601-18,0003,500
    112,701-128,70063,401-72,40040,601-46,40029,301-33,50018,001-20,6003,750
    128,701-145,90072,401-82,10046,401-52,50033,501-37,90020,601-23,3004,0004
    145,901-164,20082,101-92,40052,501-59,10037,901-42,70023,301-26,3004,250
    164,201-183,40092,401-103,10059,101-66,00042,701-47,70026,301-29,3004,500
    183,401-203,700103,101-114,60066,001-73,30047,701-53,00029,301-32,6004,750
    203,701-225,200114,601-126,70073,301-81,10053,001-58,60032,601-36,0005,000
    225,201-247,700126,701-139,40081,101-89,20058,601-65,40036,001-39,6005,250
    247,701-271,200139,401-152,60089,201-97,70065,401-70,60039,601-43,4005,500
    271,201-295,900152,601-166,50097,701-106,50070,601-77,00043,401-47,4005,750
    295,901-Greater166,501-Greater106,501-115,80077,001-83,70047,401-51,5006,000
    115,801-125,50083,701-90,60051,501-55,7006,250
    125,501-135,50090,601-97,90055,701-60,2006,500
    135,501-145,80097,901-106,80060,201-64,8006,750
    145,801-156,700106,801-113,20064,801-69,6007,000
    156,701-167,900113,201-121,30069,601-74,6007,250
    167,901-179,400121,301-129,60074,601-79,8007,500
    179,401-191,400129,601-138,30079,801-85,1007,750
    191,401-Greater138,301-Greater85,101-Greater8,000

    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 systemValue in Table B105.1(2)Duration in Table B105.1(2)
    Section 903.3.1.1 of the International Fire Code25% of the value in Table B105.1(2)aDuration in Table B105.1(2) at the reduced flow rate
    Section 903.3.1.2 of the International Fire Code25% of the value in Table B105.1(2)bDuration 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.

    SECTIONB106
    REFERENCED STANDARDS

    ICC IFC—15

    International Fire Code

    Tables B105.1(1) and B105.2

    NFPA 1142—12

    Standard on Water Supplies for Suburban and Rural Fire Fighting

    B103.3