Cathedral ceiling insulation
I’ve got a cathedral ceiling built of 2×12’s. Currently insulated with R-38 fiberglass batts with no regard to air sealing. I’ve gotten quotes to spray foam the ceiling to R-38 with closed cell foam for $4,400. I also got quotes to re-drywall the ceiling after it is all done for $2k. I could be into this project for nearly $6500… yikes!!!
Do I have any other less costly options? Yes, I’ve read the article “How to build a cathedral ceiling.” I think that I need to be a unvented since the geometry does not lend itself to a unvented.
I have included a picture of my roof. The wall that is facing you is the north wall to the great room with the cathedral ceiling. You can see that the roof from the second story comes down to the cathedral part. The cathedral ceiling goes all the way to the blue line wall. The red circle shows were I had nasty ice dams last winter.
There is a stairway that goes to the second story behind those two windows. This gives me about half the area that has a straight shot to the soffit. Above the ceiling (on the part where the roof comes down from the second story) is open to the vented attic space.
Can I build a vented assembly on the one side and rely on the attic to vent the other side? I assume that stairway cutout has some issues which result in my ice dams. Maybe I just cut out the stairway part and spray foam it? As I type this, I’m beginning to think that my best option is to spray foam the entire ceiling.
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