NFPA #13R residential sprinklers in corridor. See anything wrong?

[SprinklerDesigner2]

I'm laying out the corridor sprinklers in a four story hotel using residential sprinklers.

The ceiling is a mix of 2'x2' tile and drywall. The 2'x2' tile ceilings are at 8'-6" above finished floor while the drywall portions are at 8'-0" above finished floor.

All sprinkler heads are through drywall ceiling area.

Refer to partial drawing

http://img505.imageshack.us/img505/5128/hotelbh2.jpg

I am pretty sure this layout is fine but something is gnawing at me that I just can't put my finger on. Do you see anything wrong with this layout?

Thanks

 

[cdafd]

Are you jumping form about eight foot spacing to 16 to 17 foot spacing?????

What is the coverage of the head proposed 15 foot or is it extended coverage.

need a little more info

 

[SprinklerDesigner2]

Am looking at using the Viking Residential Pendent VK436 (5.2 K)SIN: VK436

http://www.vikinggroupinc.com/databook/sprinklers/residential/081202.pdf

I've got 160 psi available so spacing can be up to 20' in accordance with its listing.

Minimum spacing is 8'-0".

My concern is the pockets formed by the tile ceiling. I think I am alright here but something is bugging me about it and when that happens I am usually missing something. It's something about the pockets that's bugging me.

 

[cdafd]

Look at 8.6.7 and 8.8.7 nfpa 13 2002 edition

They are getting away from sprinklers in pockets, skylights, etc.

I would not worry about them, but that is a call sight unseen, but still do no think there is a problem. The heads are going to activatemore than likely with no delay

 

[TravisMack]

A couple things come to mind, and this may be what is bugging you:

1 - Residential sprinklers need to have the deflector at a maximum of 4" below the ceiling. Therefore, if you have your heads in the low ceiling, one could argue that your deflector distances are too far from the upper ceiling.

2 - Unprotected pockets would keep you from using QR reductions if you are using the area/density calculation method. However, you will fall into a corridor calc - 5 heads so I don't think that would apply either. Also, I don't believe that is a consideration in 13R.

I have done several hotels like you have shown and have not any fire marshalls or insurance reviewers question it. Often times, you can't even get a head in that higher pocket.

Good luck!!

 

[SprinklerDesigner2]

8.6.7 Ceiling Pockets.
8.6.7.1 Sprinklers shall be required in all ceiling pockets.
8.6.7.2 The requirements of 8.6.7.1 shall not apply where all of the following are met:
(1) The total volume of the unprotected ceiling pocket does not exceed 1000 ft3.
(2) The depth of the unprotected pocket does not exceed 36 in.
(3) The entire floor under the unprotected ceiling pocket is protected by the sprinklers at the lower ceiling elevation.
(4) Each unprotected ceiling pocket is separated from any adjacent unprotected ceiling pocket by a minimum 10 ft horizontal distance.
(5) The unprotected ceiling pocket is constructed of noncombustible or limited combustible construction.
(6) Skylights not exceeding 32 ft2 shall be permitted to have a plastic cover.
(7) Quick response sprinklers are utilized throughout the compartment.

Thank you all.

I meet all the requirements of 8.6.7.2 with the exceptionof a minumum 10' between pockets and, since that only happens one time, I think I will go to extended coverage quick response sprinklers, add a head in the one pocket and be done with it.