# NFPA Smoke & Heat Detector Clarification Needed



## Randy L

Hey All, 

I don't have an NFPA readily available so I'm running this by here for help.

In a business (MS state owned facility actually), the 5 year old buildings (made of block & brick, and has extensive fire breaks throughout) have spaces above the drop ceilings exceeding 24" in vertical space.

I thought that this requires detectors above the ceiling tiles, as well as red placards on the bottom of the ceiling tiles, under the spot where the detectors are mounted above the tiles, so the fire crews will know where they are located.

Also, I noticed that in the rooms that have vaulted ceilings (kinda like one side of an A-frame), the detectors are placed at least 36" below the vertical rise of the ceiling. Explanation: if you ran an imaginary line horizontally from the detector locations to the wall, and then measured this line's distance to the peak of the ceiling, the distance would be at least 36". I thought it had to be 12" max.


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## wirenut1110

Not less than 4" and no more than 3' to peak of a vaulted ceilingIf the space contained no combustible material as defined by​​NFPA 220 and the ceiling tiles were secured to their T-bar by clips or other methods of fixing such as in an approved fire resistant ceiling-roof assembly or, if the authority having jurisdiction does not require total coverage.​


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## Randy L

Thanks for the clarification! Looks like they set the detectors at the maximum distance! :001_huh:


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## wirenut1110

FYI, I believe this is 02 code but it changed for 07 but of course this doesn't apply to this building but something to keep in mind for new buildings.


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## leland

Randy L said:


> Hey All,
> 
> I don't have an NFPA readily available so I'm running this by here for help.
> 
> In a business (MS state owned facility actually), the 5 year old buildings (made of block & brick, and has extensive fire breaks throughout) have spaces above the drop ceilings exceeding 24" in vertical space.
> 
> I thought that this requires detectors above the ceiling tiles, as well as red placards on the bottom of the ceiling tiles, under the spot where the detectors are mounted above the tiles, so the fire crews will know where they are located.
> 
> .


 
If it's a return air plenum, none are needed or required.

NFPA 72 chapter 5, is the starting area, and from there like any code bounces you around.


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