The design and installation of residential fire sprinkler systems shall be in accordance with NFPA 13D or Section R313.3, which shall be considered equivalent to NFPA 13D. Partial residential sprinkler systems shall be permitted to be installed only in buildings not required to be equipped with a residential sprinkler system. Section R313.3 shall apply to stand-alone and multipurpose wet-pipe sprinkler systems that do not include the use of antifreeze. A multipurpose fire sprinkler system shall supply domestic water to both fire sprinklers and plumbing fixtures. A stand-alone sprinkler system shall be separate and independent from the water distribution system.
A backflow preventer shall not be required to separate a sprinkler system from the water distribution system, provided that:
- The system complies with NFPA 13D or Section R313;
- Piping materials are suitable for potable water in accordance with the California Plumbing Code; and
- The system does not contain antifreeze or have a fire department connection.
Sprinklers shall be installed to protect all areas of a dwelling unit.
Exceptions:
- Attics, crawl spaces and normally unoccupied concealed spaces that do not contain fuel-fired appliances do not require sprinklers. In attics, crawl spaces and normally unoccupied concealed spaces that contain fuel-fired equipment, a sprinkler shall be installed above the equipment; however, sprinklers shall not be required in the remainder of the space.
- Clothes closets, linen closets and pantries not exceeding 24 square feet (2.2 m2) in area, with the smallest dimension not greater than 3 feet (915 mm) and having wall and ceiling surfaces of gypsum board.
- Bathrooms not more than 55 square feet (5.1 m2) in area.
- Detached garages; carports with no habitable space above; open attached porches; unheated entry areas, such as mud rooms, that are adjacent to an exterior door; and similar areas.
Sprinklers shall be new listed residential sprinklers and shall be installed in accordance with the sprinkler manufacturer's installation instructions.
Except as provided for in Section R313.3.2.2, sprinklers shall have a temperature rating of not less than 135°F (57°C) and not more than 170°F (77°C). Sprinklers shall be separated from heat sources as required by the sprinkler manufacturer's installation instructions.
Sprinklers shall have an intermediate temperature rating not less than 175°F (79°C) and not more than 225°F (107°C) where installed in the following locations:
- Directly under skylights, where the sprinkler is exposed to direct sunlight.
- In attics.
- In concealed spaces located directly beneath a roof.
- Within the distance to a heat source as specified in Table R313.3.2.2.
TABLE R313.3.2.2
LOCATIONS WHERE INTERMEDIATE TEMPERATURE SPRINKLERS ARE REQUIRED
| HEAT SOURCE | RANGE OF DISTANCE FROM HEAT SOURCE WITHIN WHICH INTERMEDIATE TEMPERATURE SPRINKLERS ARE REQUIREDa,b (inches) |
| Fireplace, side of open or recessed fireplace | 12 to 36 |
| Fireplace, front of recessed fireplace | 36 to 60 |
| Coal and wood burning stove | 12 to 42 |
| Kitchen range top | 9 to 18 |
| Oven | 9 to 18 |
| Vent connector or chimney connector | 9 to 18 |
| Heating duct, not insulated | 9 to 18 |
| Hot water pipe, not insulated | 6 to 12 |
| Side of ceiling or wall warm air register | 12 to 24 |
| Front of wall mounted warm air register | 18 to 36 |
| Water heater, furnace or boiler | 3 to 6 |
| Luminaire up to 250 watts | 3 to 6 |
| Luminaire 250 watts up to 499 watts | 6 to 12 |
For SI: 1 inch = 25.4 mm.
- Sprinklers shall not be located at distances less than the minimum table distance unless the sprinkler listing allows a lesser distance.
- Distances shall be measured in a straight line from the nearest edge of the heat source to the nearest edge of the sprinkler.
Piping shall be protected from freezing as required by the California Plumbing Code. Where sprinklers are required in areas that are subject to freezing, dry-sidewall or dry-pendent sprinklers extending from a nonfreezing area into a freezing area shall be installed. Where fire sprinkler piping cannot be adequately protected against freezing, the system shall be designed and installed in accordance with NFPA 13D.
Sprinkler coverage requirements and sprinkler obstruction requirements shall be in accordance with Sections R313.3.2.4.1 and R313.3.2.4.2.
The area of coverage of a single sprinkler shall not exceed 400 square feet (37 m2) and shall be based on the sprinkler listing and the sprinkler manufacturer's installation instructions.
Sprinkler discharge shall not be blocked by obstructions unless additional sprinklers are installed to protect the obstructed area. Additional sprinklers shall not be required where the sprinkler separation from obstructions complies with either the minimum distance indicated in Figure R313.3.2.4.2 or the minimum distances specified in the sprinkler manufacturer's instructions where the manufacturer's instructions permit a lesser distance.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
FIGURE R313.3.2.4.2
MINIMUM ALLOWABLE DISTANCE BETWEEN SPRINKLER AND OBSTRUCTION
Pendent sprinklers within 3 feet (915 mm) of the center of a ceiling fan, surface- mounted ceiling luminaire or similar object shall be considered to be obstructed, and additional sprinklers shall be installed.
Sidewall sprinklers within 5 feet (1524 mm) of the center of a ceiling fan, surface- mounted ceiling luminaire or similar object shall be considered to be obstructed, and additional sprinklers shall be installed.
The solvent cementing of threaded adapter fittings shall be completed and threaded adapters for sprinklers shall be verified as being clear of excess cement prior to the installation of sprinklers on systems assembled with solvent cement.
Painting, caulking or modifying of sprinklers shall be prohibited. Sprinklers that have been painted, caulked, modified or damaged shall be replaced with new sprinklers.
Sprinkler piping shall be supported in accordance with the requirements for cold water distribution piping. Sprinkler piping shall comply with all requirements for cold water distribution piping. For multipurpose piping systems, the sprinkler piping shall connect to and be a part of the cold water distribution piping system.
Exception: For plastic piping, it shall be permissible to follow the manufacturer's installation instructions.
Nonmetallic pipe and tubing, such as CPVC, PEX, and PE-RT shall be listed for use in residential fire sprinkler systems.
Nonmetallic pipe and tubing systems shall be protected from exposure to the living space by a layer of not less than 3/8 inch (9.5 mm) thick gypsum wallboard, 1/2 inch thick plywood (13 mm), or other material having a 15 minute fire rating.
Exceptions:
- Pipe protection shall not be required in areas that do not require protection with sprinklers as specified in Section R313.3.1.2.
- Pipe protection shall not be required where exposed piping is permitted by the pipe listing.
With the exception of shutoff valves for the entire water distribution system, valves shall not be installed in any location where the valve would isolate piping serving one or more sprinklers.
Piping beyond the service valve located at the beginning of the water distribution system shall not serve more than one dwelling.
A means to drain the sprinkler system shall be provided on the system side of the water distribution shutoff valve.
The flow for sizing the sprinkler piping system shall be based on the flow rating of each sprinkler in accordance with Section R313.3.4.1 and the calculation in accordance with Section R313.3.4.2.
The minimum required flow for each sprinkler shall be determined using the sprinkler manufacturer's published data for the specific sprinkler model based on all of the following:
- The area of coverage.
- The ceiling configuration.
- The temperature rating.
- Any additional conditions specified by the sprinkler manufacturer.
The design flow rate for the system shall be based on the following:
- The design flow rate for a room having only one sprinkler shall be the flow rate required for that sprinkler, as determined by Section R313.3.4.1.
- The design flow rate for a room having two or more sprinklers a shall be determined by identifying the sprinkler in that room with the highest required flow rate, based on Section R313.3.4.1, and multiplying that flow rate by 2.
- Where the sprinkler manufacturer specifies different criteria for ceiling configurations that are not smooth, flat and horizontal, the required flow rate for that room shall comply with the sprinkler manufacturer's instructions.
- The design flow rate for the sprinkler system shall be the flow required by the room with the largest flow rate, based on Items 1, 2 and 3.
- For the purpose of this section, it shall be permissible to reduce the design flow rate for a room by subdividing the space into two or more rooms, where each room is evaluated separately with respect to the required design flow rate. Each room shall be bounded by walls and a ceiling. Openings in walls shall have a lintel not less than 8 inches (203 mm) in depth and each lintel shall form a solid barrier between the ceiling and the top of the opening.
The water supply shall provide
not less than the required design flow rate for sprinklers in
accordance with Section R313.3.4.2 at a pressure not less
than that used to comply with Section R313.3.6. Where a
water supply serves both domestic and fire sprinkler systems,
5 gpm (19 L/min) shall be added to the sprinkler system
demand at the point where the systems are connected,
to determine the size of common piping and the size of the
total water supply requirements where no provision is
made to prevent flow into the domestic water system upon
operation of a sprinkler. For multipurpose piping systems,
the 5 gpm (19 L/min) demand shall be added at the domestic
connection nearest the design area. This demand may
be split between two domestic connections at 2.5 gpm (10
L/min) each.
Where a dwelling unit water supply is from a tank system, a private well system, a pump, or a combination of these, the available water supply shall be based on the minimum pressure control setting for the pump.
The water supply shall have the capacity to provide the required design flow rate for sprinklers for a period of time as follows:
- Seven minutes for dwelling units one story in height and less than 2,000 square feet (186 m2) in area. For the purpose of determining the area of the dwelling unit, the area of attached garages and attached open carports, porches, balconies and patios shall not be included.
- Ten minutes for dwelling units two or more stories in height or equal to or greater than 2,000 square feet (186 m2) in area. For the purpose of determining the area of the dwelling unit, the area of attached garages and attached open carports, porches, balconies, and patios shall not be included.
Where a well system, a water supply
tank system, a pump, or a combination thereof, is
used, the configuration for the system shall be one of
the following:
- The water supply shall serve both domestic and fire sprinkler systems. Any combination of well capacity and tank storage shall be permitted to meet the capacity requirement.
- A stand-alone tank is permitted if the following
conditions are met:
- The pump shall be connected to a 220- volt circuit breaker shared with a common household appliance (e.g., range, oven, dryer),
- The pump shall be a stainless steel 240-volt pump,
- A valve shall be provided to exercise the pump. The discharge of the exercise valve shall be piped to the tank, and
- A sign shall be provided stating "Valve must be opened monthly for 5 minutes."
- A means for automatically refilling the tank level so that the tank capacity will meet the required water supply duration in minutes shall be provided.
The potable water supply to automatic fire sprinkler shall be protected against backflow by a double check backflow prevention assembly, a double check fire protection backflow prevention assembly, a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly.
Exception: Where permitted by Section R313.3.1.1, backflow protection for the water supply system shall not be required.
Where systems contain chemical additives or antifreeze, or where systems are connected to a nonpotable secondary water supply, the potable water supply shall be protected against backflow by a reduced pressure principle backflow prevention assembly or a reduced pressure principle fire protection backflow prevention assembly. Where chemical additives or antifreeze is added to only a portion of an automatic fire sprinkler or standpipe system, the reduced pressure principle fire protection backflow preventer shall be permitted to be located so as to isolate that portion of the system.
The piping to sprinklers shall be sized for the flow required by Section R313.3.4.2. The flow required to supply the plumbing fixtures shall not be required to be added to the sprinkler design flow.
Piping supplying sprinklers shall be sized using the prescriptive method in Section R313.3.6.2 or by hydraulic calculation in accordance with NFPA 13D. The minimum pipe size from the water supply source to any sprinkler shall be 3/4 inch (19 mm) nominal. Threaded adapter fittings at the point where sprinklers are attached to the piping shall be a minimum of 1/2 inch (13 mm) nominal.