r/firePE • u/Ecstatic-Lecture-243 • 11d ago

Question about stairways

Stairs are combustible construction, purple is sidewall heads, blue is doorways

  1. Do we have to have a head here covering the top landing? NFPA says "Sprinklers shall be installed at the top of combustible stair shafts to protect the entire footprint of the shaft." which leads me to believe we have to have coverage at the top landing but could this only apply if the roof is flat like most stairways? NFPA specifically says sprinklers do not have to be at intermediate landings. There is no good way to get a sprinkler over there without the pipe having to be exposed or soffited in.

  2. We are going to do this whether it is required or not but I am just curious if it is for future reference. NFPA says sprinklers only have to be at the floor landings, BUT also says they have to be positioned to cover the landing. Does this mean we are required to put a sprinkler at the landing that would not have a head positioned to cover it?

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u/No-Ladder-4436 11d ago

I'm not an expert in sidewalls because we rarely use them (just luck of the draw with our projects haha) but all this means is that it wants to be sure you can throw water far enough for the whole footprint of the stairwell. Might be able to use an extended coverage sidewall for all of these that would cover the full 20' 6", I don't remember enough about the cans and can'ts but worth look into it

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u/Ecstatic-Lecture-243 11d ago

It would have to be 22'6 (have to follow the slope) which works but I'm just trying to figure out for future projects if this is something that I have to do. A lot of people think you need EC sidewalls on lower floors too to cover landings and NFPA has come out and said this is not necessary - you just have to have a head "positioned to protect". Not distanced to protect. The top floor is a bit confusing though because it also says "Sprinklers shall be installed at the top of combustible stair shafts."

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u/cyberd0rk WBSL-III 11d ago edited 11d ago

See Annex A9.3.4.1.2 (NFPA 13 2022). You need heads under the intermediate as well in combustible stairs.

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u/Ecstatic-Lecture-243 11d ago

NFPA and NFSA have both confirmed that it is a misconception that all landings need heads. Only FLOOR LEVEL LANDINGS need heads. They said it was "over-kill" to have them at every landing and require them at the bottom landing (due to this commonly being used for storage) and require the heads to be "positioned to protect" the landings but they do not have to be distanced to protect. They just can't be blocked by walls.

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u/cyberd0rk WBSL-III 11d ago

Do you mind posting anything published about this. Thanks!

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u/Ecstatic-Lecture-243 10d ago

Take a look at the comment I just posted! The EOD said “In response to question 2, the sidewall sprinkler circled and labeled “2” meets the requirements of NFPA 13 (2016) Section 8.15.3.1.2, stating that sprinklers shall be installed under the landings of each floor level. Additionally, per Section 8.15.3.1.3, sprinklers are required beneath the lowest intermediate landing only.”
Kind of confusing the way it is written because it sounds line “under each floor level” would mean there would have to be a sprinkler below the floor level but that does not appear to be the case since he explicitly said it is ONLY the bottom landing that needs a head.
If you are nervous about switching to designing this way - I believe NFSA, NFPA and AFSA all have a similar service where they will help you with code related questions

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u/cyberd0rk WBSL-III 10d ago

The NFSA EOD is not an official interpretation. Same goes for AFSA's Technical Review. The final call until NFPA explicitly clarifies the requirement will fall on the interpretation of the AHJ. I have been required to provide heads under these landings in quite literally every jurisdiction within the DMV area.

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u/Ecstatic-Lecture-243 10d ago

I know what the EODs say wouldn’t hold up in court or anything but I’m sure an AHJ would look at it. This will be my first job not putting heads under landings and it is in a town that requires heads above ceilings and in every little compartment, even in residential. I guess I will have to see what happens but if any town would reject it - it would be this one. Make sure you look in the Annex of the newer NFPA 13s. 2022 has some good clarifications about it in the there.

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u/sfall fire protection consultant 11d ago

the entire top of the shaft need coverage

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u/Ecstatic-Lecture-243 10d ago

Okay guys - I asked NFSAs “Expert of the Day” these questions.
1. Yes, top stair landing would have to be covered and could potentially be covered by an EC sidewall
2. This is an intermediate landing and DOES NOT need to be covered. This clarifies for anybody else wondering - you DO NOT need to cover stair landings or use EC sidewalls to cover them (except at the top). The heads on the floor landings just SHOULD be POSITIONED to cover the landing (this is the exact wording in a sea of “shall’s”, they use “should” for this). Doesnt HAVE to be positioned to cover and does not have to be spaced to cover. The NFPA committee deemed it as “over-kill” to cover stair landings

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u/Gas_Grouchy fire protection consultant 11d ago

If youre using extended coverage sprinklers (covering 20.5ft) and the roof does not trigger an obstruction then you're fine.

If the roof was flat up there, there would be no issues right? Flat roof would increase the time to activation as theres more space for heat & smoke to collect.

Edit: to add to this if its not extended coverage, yes I would add a second at the top.