Ceiling Over 24-ft Outside the Scope of 13R, 13D?

7/7/2021

13, 13R, 13D: Calculations and High Ceilings

I was reading through NFPA 13 (2016 ed.) and caught Section 8.10.2.2:
Residential Sprinklers shall not be permitted to be used on ceilings with slopes greater than 8 or 12 or ceiling heights greater than 24 feet unless specifically listed for this purpose.

This got me curious about how it affects NFPA 13R and 13D, checking into those I didn't see any restrictions where residential sprinklers stop being allowed at the ceiling height, however the maximum 24-ft ceiling was noted in NFPA 13D (2019) 10.2.1 and NFPA 13R (2019) 7.1.1.3.1 in regards to design sprinklers.

So am I correct in assuming that if you have a residence with a 24'-1" foot ceiling in the family room (say there's a loft second floor), that you now have to calculate and design the space per NFPA 13 rather than 13R or 13D (as that ceiling height is outside of the scope of 13R and 13D)?

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6 Comments

Mike

7/7/2021 08:09:00 am

I'd check the data sheet first and 24'-1“ exceeds the height limits.

Is this a real project or just hypothetical?

Pete

7/7/2021 08:24:13 am

It was a hypothetical.

CJ Bonczyk

7/7/2021 09:11:40 am

NFPA 13 D & R 2016 Handbook clarifies this in the commentary under 6.4.3.

Sprinklers shall be installed in accordance with their listing where the type of ceiling configuration is referenced in the listing.

Manufacturers used to test and publish separate discharge criteria for sloped ceilings. The Fire Protection Research Foundation (FPRF) conducted testing on flat sloped and beamed sloped ceilings using residential sprinklers. The resulting report, “Analysis of the Performance of Residential Sprinkler Systems with Sloped or Sloped and Beamed Ceilings,' can be found on the FPRF website (http://www.nfpa.org/research/fire-protection-research-foundation) and is listed at the end of this chapter. Based on the success of those tests, residential sprinklers no longer need to be listed for this type of ceiling configuration up to 24 ft (7.3 m) and a slope of 8 in 12 in compartments 600 W (55.7 m') and smaller. See 7.1.1.3.1 for the design criteria. If sloped ceilings exceed these parameters, refer to 6.4.4.

In addition to sloped ceilings, other types of ceilings have proved difficult for residential sprinklers, specifically, ceilings with deep beams that create channels for heat to move away from sprinklers and activate sprinklers remote from the fire. Some manufacturers have dealt with the problem by acquiring special listings for their sprinklers to handle beamed channel configurations. However, these listings are extremely specific to the arrangement, depth, and spacing of the beams. Although the beam configurations addressed in 7.1.1.3.1 (2) were not part of the FPRF tests, the committee has provided guidance for these specific configurations.

7/7/2021 09:15:14 am

* Typo Correction*

compartments 600 ft² (55.7m²) and smaller.

Todd Wyatt

7/7/2021 09:30:28 am

NFPA 13D is a referenced standard per the "applicable" International Residential Code (IRC). "Fire sprinkler systems" are referenced in the 2021 IRC per P2904 which determines the scoping requirements. IRC 2904.1.1 states "sprinklers shall be installed to protect ALL areas of a dwelling unit" but does not include an exception to spaces +24 feet in height. Based on this IRC requirement and the NFPA 13D restriction of using residential sprinklers in spaces +24 feet in height, I would interpret that sprinkler heads meeting NFPA 13 would be required where the IRC requires ALL areas of a dwelling unit to be protected by a sprinkler system and that spaces +24 feet in height would require NFPA 13 sprinkler heads.

Jason Pivnik

10/12/2022 11:10:49 am

Do you know of any residential sprinkler listed for ceilings over 24'?

Ceiling Over 24-ft Outside the Scope of 13R, 13D?

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