The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance or legislation of the jurisdiction.
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.
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.
RURAL AREA. For commercial and multi-unit residential buildings, an area that is more than 1 mile (1.6 km) from
public water systems capable of providing the required fire flow. For detached single-family dwellings, an area that
is more than 1,000 feet (304.8 m) from public water systems capable of providing the required fire flow.
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, in accordance with B103.1.1 through B103.1.3.
For buildings other than Group A, E, H and I occupancies less
than 2,000 sq ft (186m2) in area, fire-flow is not required where the building is a minimum of 30 feet from all real
and assumed property lines to property with an existing structure or that can be built upon. Group A, E, H and I
buildings located a minimum of 30 feet from all real and assumed property lines are permitted to be protected with
fire sprinklers in lieu of fire flow.
Exception:
For detached single-family buildings, the building must be a minimum of 10 feet from all real
and assumed property lines to property with an existing structure or that can be built upon.
For buildings
2,000 sq ft (186 m2) or greater where fire sprinklers are not otherwise required, the installation of fire sprinklers in
accordance with this code shall be allowed to provide protection in lieu of fire-flow, where the building is a minimum
of 30 feet from all real and assumed property lines to property with an existing structure or that can be built upon.
Exception:
For detached single-family buildings, the building must be a minimum of 10 feet from all real
and assumed property lines to property with an existing structure or that can be built upon.
The fire code official is authorized to increase the fire-flow requirements where conditions indicate an unusual susceptibility to group fires or conflagrations. An increase shall be not more than twice that required for the building under consideration.
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.
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.
Portions of buildings that 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.
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.
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).
| FIRE FLOW CALCULATION AREA (square feet) |
AUTOMATIC SPRINKLER SYSTEM (Design Standard) |
MINIMUM FIRE FLOW (gallons per minute) |
FLOW DURATION (hours) |
| 0-3,600 | With or without an 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 |
| 3,601 and greater | Section 903.3.1.3 of the International Fire Code or Section P2904 of the International Residential Code | 1/2 value in
Table B105.1(2) a
|
1 |
For SI: 1 square foot = 0.0929 m2, 1 gallon per minute = 3.785 L/m.
- The reduced fire flow shall be not less than 1,000 gallons per minute.
| 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.
- Types of construction are based on the International Building Code.
- Measured at 20 psi residual pressure.
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).
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 | High-rise Buildings: 75% All Other Buildings: 50% 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 | High-rise Buildings: 75% All Other Buildings: 50% of the value in Table B105.1(2)a |
Duration in Table B105.1(2) at the reduced flow rate |
For SI: 1 gallon per minute = 3.785 L/m.
- The reduced fire flow shall be not less than 1,500 gallons per minute.
For buildings equipped with an approved automatic sprinkler system, the water supply shall be capable of providing the greater of:
- The automatic sprinkler system demand, including hose stream allowance.
- The required fire flow.
| ICC IBC—18 | International Building Code | B104.2 |
| ICC IWUIC—18 | International WildlandUrban Interface Code | B103.3 |
| ICC IRC—18 | International Residential Code | Table B105.1(1) |
| NFPA 1142—17 | Standard on Water Supplies for Suburban and Rural Fire Fighting | B103.3 |