Exposed beam ceiling insulation
I am looking at adding interior insulation to my cathedral/exposed beam ceiling.
Climate zone 6B dry snowy cold climate, no AC in summer, 8,100ft elevation, Mammoth Lakes, Ca
Last summer I had my roof replaced with a standing seam metal roof with 3″ of polyiso RMAX insulation below the insulation but above the deck. I am looking at adding insulation below the roof deck between my 4×13.5 on 48″ center beams. The plan is to add 2×6’s on 24″ centers and insulate between them with Rockwool and then drywall over that.
The roof design is 23’x17′ single pitch roof, looking up at the ceiling you see the beams and the roof decking. I have attached some photos
My questions are:
1. Is this a good idea? Its really dry up here so not too concerned about moisture, or should I?
2. What type of insulation should I be putting up there? R23 Rockwool (expensive), R19 FG with or without Kraft facing (cheap)? Change my whole plan and go with polyiso Rmax foam boards with furring strips and drywall (I can source recycled boards for pretty cheap)
3. My thermal camera is showing extremely cold spots Where the roof meets the wall (rim joist/facia board?) There are also small gaps that I have caulked for the most part, should I try to cut and cobble some foam board in there or buy a spray foam kit to cover those areas?
Thanks so much!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part