Need a 2 hr fire rated wall design - Contractor Talk - Professional Construction and Remodeling Forum

miked8282 · 02-25-2009, 07:54 PM

Hi I have and existing 2 hour fire rated wall built out of 3 5/8" metal stud with 2 layers of 5/8" drywall on each side. I cut in an opeing 8' x 10' for access so my cleint can put a large boiler in. I wanted to close the opening back up by headering it off and using metal stud and then a non comp plywood on both side so that they could later unscrew it and have access again if needed.

Does anyone know of a UL listed design I could use to prove the 2 hour rating on the plywood knock out?

Snobnd · 02-26-2009, 09:22 AM

I think it would be best to put the wall back as It was.
Take a few pictures and Tape both sides.

We had a job in the local mall last year, Prints were approved, job completed just as the print showed.

The inspector for the fire department flaged us for firecode 3/4 plywood in the ceiling - MUST be covered!
3 days before the opening. We had to cover it with sheetrock and tape. I think I got stabed 50 times with with the ceiling wire. That sucked

Mud Master · 02-26-2009, 10:39 AM

A fire rated assembly must be completly sealed off. I don't know of any UL that would allow you to just fire caulk the perimeters either. Not to mention it looking like sh*t.

3 Options:

1. Re-stud opening, 2 layers of Type "X" GWB, fire tape (or block/skim/prime/paint as well if area dictates)
2. Re-stud opening, 2 layers of Type "X" GWB, install fire-rated access panel. Though I don't they make one big enough to accomplish what you want.
3. Frame a RO, install fire rated door/frame/hardware

Super-Mike · 02-27-2009, 06:07 PM

If you want access to it why not just put in a fire rated door?