Room w/out ceiling, partial height walls, how to cover properly? 2

[Jondoeiowa]

Our design chief has run into a situation that we'd appreciate some advice on.

"A small mechanical room 6'-2" X 10'-2" w/ no ceiling & walls to 9'-6" aff. Concrete deck on concrete joists bot. @ 15'-7". Surrounded by corridors & rooms w/ ACT, or gyp. bd. ceilings, no combustibles above. Will an upright placed above each wall be enough to cover the area?"

I have attached an image of what he proposes.

Thank you,
Jon
LLAP

 

[acb324]

what code governs your project?

why place the sprinklers above the walls that way if your intention is only to cover the electrical room?

I could not consider the above ceiling spaces of the other rooms as noncombustible compartments since they are completely open to the electrical space. In this situation I require the walls to extend to the structure above or I sprinkler the entire above ceiling space. I am puzzled by an electrical room not being enclosed and rated in general, what does the room contain?

 

[cdafd]

Agree walls to the deck or sprinkle entire area open to that room

 

[TravisMack]

If the area is open on all 4 sides, either get the walls to the deck, or sprinkle the entire space.

If open only on 1 side, then there is an exception in NFPA 13 that allows you to do a multiplier of the long leg of the remote area. I believe the multiplier is 0.6 or something like that.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Jondoeiowa]

Travis,

That is exactly what the engineer is claiming, that the ceiling constitutes the one side.

NFPA 13 2010 8.15.1.5
NFPA 13 2010 8.15.23

Is there a code in IBC, IFC, or NFPA we can give back to him to disprove his point?

The work is done in Des Moines, IA USA

Thank you,
Jon

 

[Jondoeiowa]

Sorry the second code 8.15.23 is a 2013 code.

 

[cdafd]

simple answer

sprinklers through out, unless section of 13 that exempts them


fire is not going to stop at the walls, it will spread up and out past that room walls that do not go to the deck

 

[acb324]

If you look at the Annex, Figure A.8.15.23.3 shows what is meant by one side. It does not mean that the ceiling is a side.

 

[cdafd]

The other thing is head activation
Will it activate at all or be a delay, because the heat is flowing into the other area adjacent to this room

 

[TravisMack]

This is clearly not one side. That exception typically applies to an office at the end of a warehouse, or something like that.

If the engineer was trying to claim the ceiling is one side, then he would still need to go about 24' into the space above the ceiling. But, it really doesn't matter, since that exception is not applicable in this scenario.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[Jondoeiowa]

Thank you all, this is exactly what we were looking for. We've replied to the engineer with this information and also sent a request to NFPA to confirm this for us. Appreciate the quick responses and all your help.

Jon