How would you handle this combustible concealed space?

[SprinklerDesigner2]

Combustible construction totally enclosed.

Bleachers in a church.

What has me is the mix between standard upright and interstitial sprinklers.

This is a cross-section and the bleachers are about 80' long so small they are not.

I've dealt with interstitial sprinklers before but nothing with varying heights as shown.

 

[TravisMack]

If you look at the tyco CC3, I believe you can have up to 60" of clear space (going from memory), so you could use them throughout. Worst case, put a draft curtain at the split between 60" and 46" area. ≤46" you can use CC3. If you want to use SSU in the 60" area you would be fine.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, a Ferguson Enterprise

http://www.mfpdesign.com

 

[SprinklerDesigner2]

Travis, whether working with interstitial sprinklers or standard uprights do you see four rows of sprinklers?

 

[cdafd]

I take it the top seat/ boxes do not need sprinklers??

Just from the top of the red line down???

You can't do it with sprinkler at the top against the yellow wall

and the next sprinkler at the back edge of the third row? Right in front of the 3'10" line?

 

[SprinklerDesigner2]

The "red lines" are simply dimensions that I added to the architectural drawing..

 

[TravisMack]

Travis, whether working with interstitial sprinklers or standard uprights do you see four rows of sprinklers?

If it were SSU, i'd do it with 2 and no QR reductions. 18" and 46" level. I would use the fact the vertical change is <36" to avoid all 4. But, the interstitial are a bit more specific. I'd do 4 levels with those sprinklers. You could possibly get one row of SSU at the 46" level and then 2 rows of interstitial at the lower 2 levels. Just need the draft curtain to separate them.

Travis Mack, SET, CWBSP, RME-G, CFPS
MFP Design, a Ferguson Enterprise

http://www.mfpdesign.com

 

[SprinklerDesigner2]

Travis, the only way I can be absolutely correct is to install four rows as shown in the sketch below:

Where the concealed space is <3' I will use interstitial sprinklers and and where >3' then QR upright probably a small orifice.

I have a baffle separating the interstitial sprinklers with the standard uprights.

I know this isn't a big thing but there's four such "bleachers" in the church so if I didn't do it correctly I would be making a mistake four times over.

Oh, and I know I show the heads lower than they should be but you get the idea.