How to insulate cathedral attic ceiling?
geoffhazel
| Posted in Construction Techniques on
My buddy just bought a “fixer.” It has a second-storey master suite that appears to have been done wth no permits. The roof deck (OSB) is laid down on open-beam 4×4 and 4×6 framing, and painted white. There is no insulation or other framing. So when you look up at your ceiling, it’s just an inch away from the outside world.
What would you recommend he do to insulate this room? He says he likes the open beam look but realizes that room will be cold in the winter and hot in the summer and also doesn’t want to fry his roof, shorten the life and void the warranty on the shingles.
Replies
Sounds to me like he's gonna have to furr up above the ceiling and insulate it from above. He could go with 2x6 and spray foam it or 14" TJI's and R-38 fiberglass, or anything in between.
Dave
frame in a new ceiling below the roof, insulate, and ventilate properly. The new ceiling could be built up to any style using timbers.
Edited 11/1/2004 9:41 am ET by Les
Geo- nothing in yer profile as to where this building is at.
Outside of a new roof and insulating on the outside he's SOL trying to keep the open beam look unless an R-10 in a cold roof is going to be enough.
You've probably read these before...
http://forums.taunton.com/tp-breaktime/messages?msg=45291.1
http://forums.taunton.com/tp-breaktime/messages?msg=35531.1
http://forums.taunton.com/tp-breaktime/messages?msg=15660.1
http://forums.taunton.com/tp-breaktime/messages?msg=27242.1
http://forums.taunton.com/tp-breaktime/messages?msg=3407.1
http://forums.taunton.com/tp-breaktime/messages?msg=38710.1
Rigid ISO insulation comes in 4x8 sheets and has built in vapour barrier. It screws directly to roof sheathing and then roofing materials apply directly over it. That is the way to retain the vaulted ceiling look but of course it requires tearing off the exisitng shingles and starting over.
Since the existing 'ceiling' is nothing visually exciting, just OSB, if it were my place I would fur down the ceiling between the beams then add vapour barrier and insulate with something thin enough to allow some air space between it and the OSB sheathing. Probably some kind of rigid product again. Then consider ventilation - maybe need remove the ridge cap shingles and top couple rows and cut in a ridge vent.
Wally