Using R-tech polystyrene insulation
newbuilder
| Posted in Construction Techniques on
Quick question: I’m trying to get R-30 into ceiling bays and I’ve come up with a set up that does it with two inches of the white polystyrene .. ((R-tech insulfoam)) which is basically just styrofoam… combined with r-21 batting. The thing is, i’ve only seen people using the yellow stuff with foil .. Polyisocyanurate (foil-faced) .. or the grey or the pink stuff. The white stuff that I’m using seems to be used primarily for foundation insulation.
So my question is, if properly installed and covered with drywall is the white Expanded Polystyrene (beadboard) perfectly ok to use as indoor insulation? For me in this situation it is the cheapest way to hit the required R-30.
Thanks!
Aaron
Replies
It's OK indoors with a flame barrier, but I think it's about R4 per inch max. Possibly a bit less.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
"If Brains was lard, you couldn't grease much of a pan"
Jed Clampitt
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GREAT! Thanks. It is about 4.17/inch .. 2 inches combined with the R-21 batting makes it about 29.34. Here in washington state they give you the building materials as well so ... 3/4 plywood on top (flat roof) is .93 and that makes it over 30 .. not even counting the drywall and the rubber roof I've got on.
Thanks again -
Aaron
Good deal. I did similar here in Ky. But I found polyiso to be a better option for me, as far as availabilty and affordability.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
"If Brains was lard, you couldn't grease much of a pan"Jed Clampitt
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