A Summary of Fire Sprinkler Standards

Here is a rough summary of water demand for the most common sprinkler standards that have been adopted by the State. Note that the Maine Life Safety and the Hydro-Pro standards are "State of Maine fabricated standards". Copies can be obtained free online by clicking "Back" in your web browser, and then clicking on the standard you want. The NFPA standards are available direct from them at 1-800-344-3555. Be aware that this info below is only a rough sketch.

NFPA 13D: Water demand is 10 minutes of water for 2 heads at 13 gpm for each head equals 2 x 13 x 10 = 260 gallons of water. If the home is less than 2000 sq ft, one story, with certain type ceilings all not over 9', then 10 minutes of water for 2 heads at 6.5 gpm for each head equals 2 x 6.5 x 10 = 130 gallons. Either way, residential heads are to be used. Pumps & pump controllers for NFPA 13D systems do not have to be listed for fire service, regardless of their size. Hose streams do not have to be included for the required water supply. Alarms are not required other than smoke alarms. Fire Department connections are not required. Heads are not required in:

Bathrooms less than 55 square feet
Closets & pantries that are under 24 square feet that are less than 3 feet deep and that have walls & ceiling of non-combustible or limited combustible materials.
Garages & carports
Porches, balconies, corridors & stairs when any of these are open & attached
Closets of any size on exterior balconies as long as they have no openings into the dwelling unit
Attics & crawl spaces that are not used for living purposes and that do not have fuel-fired equipment
Floor/ceiling spaces that do not have fuel-fired equipment
Penthouse equipment rooms
Elevator shafts & elevator machine rooms
Other concealed spaces that are not used for living purposes and that do not have fuel-fired equipment
Unheated entrance foyers that are not the only means of egress
Ceiling pockets that meet certain criteria
Our office also recognizes walk-in refrigerators, and freezers
Our office also recognizes storage areas that are accessed through trap-doors, ceiling pull-down ladders, cabinet-sized doors and access panels, as long as those areas are not for living purposes and do not have fuel-fired equipment.

Maine Life Safety: Water demand is 10 minutes of water for 3 heads at 13 gpm for each head equals 3 x 13 x 10 = 390 gallons plus 25%. When the most demanding hydraulic calculations are done, then the end result for the total required volume tends to be about 600 gallons or less. Residential or quick response sprinklers are to be used according to their listing. Areas not requiring heads are the same as for 13D. Only wet systems are allowed. Antifreeze systems are recognized as a type of wet system. Pumps & pump controllers for Maine Life Safety systems do not have to be listed for fire service, regardless of their size. There must be pump-powered monitoring, such as by sharing power supply with a refrigerator or commonly used light. When there is stored water there must be a low-air alarm or an automatic fill. Hose streams do not have to be included for the required water supply.

NFPA 13R: Water demand is 30 minutes of water for a maximum of 4 heads at 13 gpm for each head equals 4 x 13 x 30 = 1560 gallons. When the most demanding hydraulic calculations are done, then the end result for the total required volume tends to be about 2500 gallons, give or take 500 gallons. Residential heads, and in certain cases quick-response heads are to be used. The same basic exceptions in NFPA 13D for location of heads applies here, with the exception of the entrance foyer and garages, which require coverage. Also coverage must be provided in any closet that has heating & air-conditioning equipment in it. In addition, the elevator shafts must be noncombustible and used as passenger elevators to meet the exception in 13R. Fire pumps & control panels are required to be listed for fire protection service only when they are 7.5 horsepower and greater. Hose streams do not have to be included for the required water supply.

Hydro-Pro: 30 minutes of water for 4 heads at 12 gpm for each head equals 4 x 12 x 30 = 1440 gallons plus 25%. Dry systems are allowed, but require a 5 head calc at 12 gpm; equals 5 x 12 x 30 = 1800 gallons. When the most demanding hydraulic calculations are done, then the end result for the total required volume tends to be about 2500 gallons, give or take 500 gallons.Residential or quick response heads are to be used according to their listing. All the exceptions for location of heads listed in 13R apply here too. Pumps & pump controllers for Hydro-Pro systems do not have to be listed for fire service, regardless of their size. There must be pump-powered monitoring, such as by sharing power supply with a refrigerator or commonly used light. When there is stored water there must be a low-air alarm or an automatic fill. Hose streams do not have to be included for the required water supply.

NFPA 13: The calc options are more complicated in the 2007 edition. Standardly the remote area will be 900, 1500. 1950, or 2535 sq ft, depending upon type of heads, wet or dry, and ceiling height & roof pitch, or will be according to a fire sprinkler head specification. Twelve heads for 1500 sq ft tends to be an average. For light hazard occupancies this would be a total of 150 gallons for 30 minutes plus 100 gallons for hose stream, or a total of 150 x 30 = 4500. 4500 + 100 = 4600 gallons total, but some scenarios could require up to tens of thousands of gallons of water. It is best to consult a fire sprinkler designer to see what might be required for a particular situation. Different types of heads are required in different locations. NFPA 13 systems are designed to protect the building as well as the occupants. All other standards above are only designed to give time to get the people evacuated and contain the fire until the Fire Department shows up. Exceptions are typically quite different than in the other standards. Please call if there are any questions.

[Last updated 3-31-08]

Bureau Information

A Summary of Fire Sprinkler Standards