Probably, Don. Not too many ceilings have a better fire rating than an equivalent amount of cement, mortar, joint compound, etc. And- with all those pipes passing through, so close to each other- the issue of bonding this patch to the ceiling is kind of moot!
Indeed, for most such penetrations, I suspect simply packing the spaces with fiberglass, then taping over, would probably pass the fire test.
I suppose that ultimately, its' an engineering call, based upon trade practices, comparison to specific ceiling designs, and the acceptance of the AHJ.
Not to be overlooked is the way the pipe itself will conduct heat through the wall, no matter how you seal it. There's only so much a patch can do.
Re: Sealing the Ceiling#123377 03/28/0605:23 PM03/28/0605:23 PM
Sealing with concrete will work okay...as long as neither the floor nor the conduits ever move. There's no way for anything to expand with concrete. I had problems with a bus riser bending in a 5 story building because they poured concrete around it. Also, if you're using the red firestop goop be sure and check the installation instructions. The goop itself isn't the firestop; it's just a part of a UL Listed 'system'. If UL lists it with 2" of packing and 1" of goop, cramming in 3" of goop is a waste of money (that stuff ain't cheap). I've seen foam or cardboard cut around the conduits to support the packing material and then the right amount of goop on top of it. That seems to pass muster in most places.