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Question about the vk 900 QR COIN sprinkler in concealed space.

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SprinklerDesigner2

SprinklerDesigner2

Mechanical
Nov 30, 2006
1,244
US
I have a three story motel having sprinklers per NFPA 13R except the owner, and only the owner, insists the attic have sprinklers.

First two floors are non-combustible poured in place reinforced concrete with concrete block walls having metal studs and drywall. The only part of this building having combustible construction is the attic area.

As you can see not a normal sloped attic, the roof trusses gently slope to the center of the building where there are internal gutters.

2ib2ati.jpg


Maximum depth of trusses is under 3'-0" and has drywall fastened to the underside except at the entry way and bathrooms of individual units.

NFPA #13 - 2013 said:
8.15.1.6 Sprinklers used in horizontal combustible concealed spaces (with a slope not exceeding 2 in 12) with combustible wood truss, wood joist construction, or bar joist construction having a combustible upper surface and where the depth of the space is less than 36 in. (914 mm) from deck to deck or with double wood joist construction with a maximum of 36 in. (914 mm) between the top of the bottom joist and the bottom of the upper joist shall be listed for such use.
Click to expand...

I'm looking at the Viking VK900 specific application sprinkler.

What about the space with the green ??? where the depth from deck to ceiling below exceeds 3'-0"

The purple lines indicate where drywall will be fixed and as far as I can tell there isn't any drywall attched to the underside of the wood joists in the area above the bathroom or entry way.

Do I use a standard upright sprinkler in this area? If so do baffles need to be installed separating the area? I wouldn't think so but I am not sure.

IBC and it seems a very strange setup to me but I am not an architect.
 
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Not a designer

But yes appears you need a different head in the bathroom void

Unless they want to seal it off per 13 if under the sq ft

To bad the Viking is listed for three feet and you have four
 
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Just look at the spacing for each head to get the minimum required
 
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Yeah. Don't forget the draft curtains required with the specially listed concealed space sprinklers. But, you will need a standard spray sprinkler where the concealed space exceed 36". Also, if you are using CPVC, you can't use CPVC in concealed combustible spaces where the area is protected with standard spray sprinklers.

Travis Mack
MFP Design, LLC
 
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Travis,

The draft curtains are meant to bound an area of 1,000 sq ft. max which isn't a problem, how bad can ripping 1/4" plywood into *" strips and nailing them up, as long as the general contractor knows it has to be done.

Two laborers should be able to get that job done in a day.

Do I need a curtain separating the standard and special application sprinklers? I wouldn't think so, nothing I have read to date indicates it would be required, or do I put the curtains up to curtain off the bathroom areas as well?
 
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Travis:

I'm using the 2013 edition of NFPA 13. Your reference is one of those sections I am supposed to remember. Would you please cite it.

Thanks.
 
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Stookey:

You won't find reference to the draft curtains in 13 but the listing for the particular sprinkler being used.
 
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Stookey:

NFPA 13, 2013 edition:
8.15.1.6 / 8.15.1.6.1 / 8.15.1.7

Then, when you go to the listing of the sprinkler, it refers to the draft curtains being required.

SD2:

It doesn't take much to do it. However, you have to make sure that the guys per the curtains in the right spot. If you are 12' on center and centered between 2 joists that are 2' on center, then if they attach the plywood to the near side of a joist, you will end up 5' off the curtain on one side and 7' off the other size. If the spacing is limited to 12'x12' then you are going to be over-spaced. So, they have to either put the curtain between 2 joists, or you have to specify where it goes and space the sprinklers accordingly.

I have always indicated the draft curtain to separate the CC heads from the SS sprinklers. The reason being is the calc area is different. It is based on 1000 sq ft for the CC heads and anywhere from 900 - 1500 sq ft for the SS sprinklers.

Travis Mack
MFP Design, LLC
 
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Travis, the owner now wants a dry system so I am looking at the Tyco k5.5 cc head with 1300 sq ft dry system calc area. I am not sure how to calc this with a mix of ss and cc heads. I have good water so I suppose I could calculate over an area of 1950 sq ft but I would like to know for sure. This week I am spending at an nfsa ceu class to renew my nicet so I'm in a perfect place to ask.
 
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You may want to look at the new Reliable sprinkler. If your structure fits, it goes up to 16'x16' spacing. With the Reliable or Tyco head, I believe you calculate 1300 sq ft.

I would still put the draft curtain between the SSU and CC heads and calc 1950 for SSU and 1300 for CC. You could be extra conservative and calc 1950 for CC as well.

Travis Mack
MFP Design, LLC
 
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Travis,

I am spending the entire week at the Florida Fire Sprinkler Association conference learning new things every day.

One of our speakers was Matt Klaus of the NFPA. Oh yeah, you betcha I cornered the poor guy because the mix of concealed space and QR standard on a dry system had me very much concerned.

He knew right away exactly where I was going and we won't find any guidance in the standard but most AHJ's require the 1,500+30%=1,950 sq ft area of application. While nothing official Matt Klaus seemed to me to be in agreement with this approach.


 
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