Summary: Fire protection and safety standards are vital for protecting structures and people from potential risks. Understanding and applying the complexities of NFPA standards like NFPA 13, 24, and 25, among others, is critical for architects, engineers, and safety personnel. In this comprehensive blog, we delve into various questions and clarifications about these standards, covering nuanced topics ranging from sprinkler systems in multistory buildings to the specifics of fire pump flow tests and sprinkler placement in unusual settings such as combustible pergolas. Negotiate the complexity of NFPA standards by providing extensive analysis and explanations, including information on residential sidewall sprinklers, fittings beneath structures, and the use of quick response sprinklers in bathrooms. 

Let’s seek to provide clarity and assistance for professionals navigating the world of fire safety laws and applications in a variety of structural situations by unravelling these standards and addressing actual circumstances.

1. Birdcaged Sprinkler System in NFPA 13 Building. Description- NFPA 13 allows for a multistory building with horizontal first-floor plumbing and vertical risers for upper levels as long as the total square footage does not exceed 52,000. Section 16.9.10 of NFPA 13 requires floor control valve assemblies for multi-story structures but exempts buildings under 52,000 square feet for light hazard occupancies like residential spaces (as per Section 4.4.1). Question 1. Can NFPA 13 defend a multistory building with horizontal sprinkler pipe on the first floor and vertical rises to feed the floors above if the total square footage is less than 52,000 square feet?

2. Fire Pump Flow Test Evaluation. Description- Section 8.3.7.4 of the 2014 version of NFPA 25 says that if the degradation is more than 5% of the initial unadjusted acceptance test curve or nameplate, an investigation must be carried out to find the cause. Question 2. Does the 5% apply to both churn pressure and 150% capacity, or only rating capacity?

3. Sprinklers under Combustible Pergolas. Description- NFPA 13, 2016, does not provide explicit rules for sprinklers installed under pergolas. Section 8.15.7, on the other hand, discusses standards for flammable projections that are wider than 4 feet, with some exceptions. The 2022 update classifies outside projections as heat-gathering structures that require sprinklers under solid-roof pergolas unless certain noncombustible materials or regulated concealed spaces exemptions apply. Question 3. Are sprinklers required under combustible pergolas (cedar) that exceed 4 feet in width? Is Section 8.15.1.2.18 of the 2016 version of NFPA 13 applicable for this situation?

4. Residential Sidewall Sprinklers with Differing Deflector Distances. Description- Residential sidewall sprinklers in the same area can be set at different distances from the ceiling, according to NFPA 13, 2013 version. While rules recommend placing deflectors between 4 and 6 inches from the ceiling, residential sidewall sprinklers have a range of 6 to 12 inches. The specification does not require uniform placement within a compartment, allowing for variations between 4 and 12 inches to accommodate impediments and maximize sprinkler efficacy. Question 4. Is it acceptable to install residential sidewall sprinklers at different heights from the ceiling (e.g., 6 inches and 12 inches) to reduce the impact of a nearby blockage on only one of the sprinklers?

5. Fittings Under a Building. Description- NFPA 24 authorizes underground pipe to extend 10 feet beneath the building. Question 5. Is it acceptable to install a horizontal elbow on the water service entry under a structure as long as the 10 feet dimension is not exceeded?

6. Shadow Areas Outside the Coverage Area Sprinkler. Description- A sprinkler system is installed in a residential structure following the 2016 edition of NFPA 13R standards. NFPA 13R permits for shadow regions of up to 15 square feet. Question 6. Can shadow area provisions apply to corridor ends where sprinklers cannot reach?

7. Automatic Ball Drip Location. Description- A ball drip must be installed between the check valve and the Fire Department Connection (FDC) in a new freezing-zone dry pipe sprinkler system that complies with NFPA 13, 2016 edition. This automated drain reduces water accumulation, aids in system maintenance by keeping the piping dry, and ensures effective firefighting capabilities in emergencies. Positioning the ball drip at the lowest point of the FDC piping ensures proper drainage and prevents freezing. Question 7. Can you place a ball drip somewhere between the check valve and the FDC?

8. Private Waterworks System. Description- A new prison is being built with a sprinkler system in line with the 2022 edition of NFPA 13. The project will contain a private tank and pump for both domestic water and a fire loop. The pump is a domestic kind that does not comply with NFPA 20. Question 8. Can a residential pump and tank supply both domestic water and a fire loop in a prison?

9. Unreinforced Plastic Pallets Without Marking. Description- The project owner believes the plastic pallets are unreinforced; however, they are not marked. According to the 2019 edition of NFPA 13, unreinforced plastic pallets are now classified into one class and reinforced plastic pallets into two. NFPA 13 requires unreinforced pallets to be permanently marked. Question 9. Does Section 20.3.2.2.1.1 require the maker to supply the permanent symbol showing the pallet's reinforcement, or can the oner do so?

10. Underground Valves and Monitoring. Description- An underground gate valve in a roadway box is part of a private underground water main. In NFPA 24, it says that these valves don't need to be watched. But in Section 903.4 of the International Fire Code, there doesn't seem to be an exception to the need for supervision for underground valves. Question 10. Is it necessary to electrically supervise subsurface gate valves in sprinkler system highway boxes?

11. Sprinklers that respond quickly Bathrooms in NFPA 13R. Description- According to the 2016 version of NFPA 13R, quick-response sprinklers can replace residential sprinklers when there are four or fewer units per housing unit. NFPA 13R enables sprinklers to be removed from restrooms measuring 55 square feet or less. Question 11. Can quick response sprinklers replace residential sprinklers for small bathrooms?

12. Obstruction on Same Wall as Extended Coverage Sidewall Sprinkler. Description- A mechanical duct protrudes from the same wall where an extended coverage sidewall sprinkler will be put. Please see the attached figure. Question 12. Is this an obstacle to the sprinkler? What is the appropriate obstruction rule based on the 2022 edition of NFPA 13?

Courtesy: Roland Asp, CET, TechNotes