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Camelot One
MVM
join:2001-11-21
Bloomington, IN

Camelot One

MVM

Code question - fire blocking behind soffit

I am a little confused on the fire blocking code requirement, so I wanted to run this one by the experts before I get too much further. I have soffits running down both sides of my new theater room, forming an L at the wall to ceiling corner. My area follows IBC 2006.
»www.optasoft.com/applica ··· 17.2.htm

From my reading of it, Mineral Wool insulation would be enough, and I assume it gets packed just in the joist and stud cavities, but it doesn't specifically state that. Do I need to also pack the soffit itself? I would rather not, as the recessed fixtures I've already ordered for it are non-IC rated. And would my soffits fall under "717.2.2 Concealed wall spaces" with the 10' max horizontal run? If so, do I just need to create a drywall break to split the soffit up? (its 20' 9" long)



Tex
Dave's not here
Premium Member
join:2012-10-20

Tex

Premium Member

From what I've read, I think all you need to do is fire block the stud cavities.



Camelot One
MVM
join:2001-11-21
Bloomington, IN

Camelot One

MVM

Are those 2x4 blocks in addition to the mineral wool, or in place of? I had planned on filling the entire floor to ceiling stud cavities and across the ceiling between the joists with mineral wool anyway, primarily for the sound proofing.

Tex
Dave's not here
Premium Member
join:2012-10-20

Tex

Premium Member

Again, from what I've read, there are several options. Your link to IBC 717.2.1 list the materials and their thicknesses, 2-by being one option. Mineral wool is another option as long as it is "installed in such a manner as to be securely retained in place..."

John Galt6
Forward, March
Premium Member
join:2004-09-30
Happy Camp

John Galt6 to Camelot One

Premium Member

to Camelot One
You could have put up rated sheetrock prior to building the soffit on the vertical and horizontal surfaces to isolate the soffit from the rest of the structure. The sheetrock would have extended several inches past the metal stud framing, allowing you access to complete any work prior to finishing the rest of the sheetrock on the walls and wrapping the soffit.

You've made more work for yourself proceeding as you have...

Camelot One
MVM
join:2001-11-21
Bloomington, IN

Camelot One

MVM

I debated that, but sheetrock wasn't an option on one side, as the wall stops at the soffit, with the soffit running around the main sewer line.