I need to put up a ceiling under a house addition that extends 25’x35′ out from the existing, and is up on columns, 12 feet off the ground.
Homeowner want’s vinyl sofit paneling, with rigid foam insulation up first to seal the floor joist area.
Someone mentioned to me a while back to use osb or ply for this, but I was thinking rigid foam should work better for insulation. I wasn’t sure, however, about any fire safety issues with this, since fire could go up thru the vinyl / foam quicker than it could vinyl / plywood. The finished floor up top is hardwood.
I have not gotten my code book that I have ordered in the mail yet, so If anyone has input on this, it’s greatly appreciated.
thanks…st
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I need to put up a ceiling under a house addition . . . The finished floor up top is hardwood.
So, this is a finished exterior treatment of the bottom of an interior floor, right?
You generally treat that like a "stockade" overhang.
Which generally means insulating to match the exterior walls. It probably should have the same water/damp proofing as the walls, and carried right under. That gives you "sheathing" as a ceiling substrate--which can look odd. The finish of the ceiling is only limited by the transition to the wall finish--so, it could be vinyl, could be the wall finish.
yes, this is a finish treatment to the bottom of an interior floor.
Right now there are 2x10 joist with fiberglass bats up between them. the siding of house is vinyl.
I'd put rigid foam up on an exterior wall, and cover it with vinyl siding (as long as the interior wall was gypson board for fire protection) with no questions asked. Just wanted to make sure that the same was appropriate for the area under the finished floor.
Seems like it would be alright, but still wanted to ask around a little before I got started.
thanks...st