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I'm reviewing a fire sprinkler system under 2019 NFPA 13D for a single family dwelling. The living room basically has "reverse" ceiling pockets as the pockets are lower than the rest of the ceiling (pockets are at 10'-7", the ceiling is at 12'-1"). They have 2 sprinklers in each of the 3 lower sections of the ceiling but no sprinklers in the higher areas (except for a room to the side but in the same area). It seems off to me to omit sprinklers in the higher area but can't figure out how to apply a code to it. Would you apply the ceiling pocket rule if the higher area exceeds 100 cubic feet or is it fine as designed?  Thanks in advance. Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe
11 Comments
Anthony
11/28/2023 07:36:27 am
I think you need to add 3 sprinklers. 1 to each "reverse pocket," generally I'd call these clouds. Then space the other sprinklers around the clouds such that you don't have any dead spots over 15ft^2. See NFPA 13D 2019 8.2.5.7.
Glenn Berger
11/28/2023 08:11:21 am
Additional sprinklers are required. I typically use the position of the deflector with respect to the ceiling clause.
James Evans
11/28/2023 08:16:27 am
As allowed by NFPA 13D, as long as the volume does not exceed 100 cubic feet then the sprinklers in the high area are not required. Even in NFPA 13 if the change in elevation does not exceed 3'-0" you are allowed to space sprinklers as if the elevation change is not there. The sprinkler spacing you are showing does not exceed the area for a residential sprinkler, so in my opinion if the volume does not exceed 100 cubic feet then they are fine.
Mickey
11/28/2023 08:33:26 am
Are they using standard spray sprinklers or residential sprinklers? It's odd that the 2019 Edition of 13D does not mention a maximum depth of the pocket requirement. NFPA 13 has a 36" maximum for standard spray and 12" maximum for residential sprinklers.
Jesse
11/28/2023 08:35:03 am
Its difficult to tell. I don't think the combined volume of the higher areas would require protection.
Casey Milhorn
11/28/2023 08:50:52 am
What Anthony said. Shift the heads north and south out of the lower ceilings, and add 3 heads, (1) in each lower ceiling area (watch out for that fan though). Not sure what your water supply is, but also seems like heads are spaced at 14'x14' or 16'x16'. If you don't have a volume or pressure issue, max those things out to 20'x20' and save heads in other areas possibly. The upper right area seems like it should only need 1 sprinkler from left to right. If you are working through a 3/4" meter, then forget what I said and keep them at 14'x14' to avoid exceeding listed gpm rating on meter. If you have a full 1" meter, or pump and tank setup, max those heads out.
Michael
11/28/2023 08:51:45 am
I think you would consider these ceiling pockets.
Alex
11/28/2023 09:58:50 am
I'm swaying more on the side of adding heads in the higher ceiling.
Peter Googins
11/28/2023 10:48:12 am
I agree. Just the little two areas between the drop ceiling (rough guestimation) 2ftx2ftx14=56 cu ft, times that by two is 112 cu ft?
DE
11/28/2023 12:05:43 pm
What Anthony and Casey said. Unprotected volume definitely exceeds 100cuft. Sprinklers required in the 12'-1" ceiling.
Dan Wilder
11/28/2023 11:01:51 pm
The NFPA definition of a ceiling pocket is : An architectural ceiling feature that consists of a bounded area of ceiling located at a higher elevation than the attached lower ceiling. Leave a Reply. |
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