Rigid board for cathedral ceiling
I just tore out the drywall on my cathedral ceiling on my lean-to addition and found no insulation at all...just the underside of the roof sheathing. I want to insulate before drywalling but can't seem to find any consistent information on how it should be done. I was going to go with spray foam but $1k for 96 sqft is crazy. I am thinking about going with ridged board against the bottom of the roof sheathing...maybe an R30. Will this work? Will I have any concerns with moisture? The spray foam guy said that he could spray the foam right up against the roof with no moisture problems at all...I am guessing this would be the same for rigid...I hope. Any advise?
Posted Dec 7, 2012 2:49 PM ET
Other Questions in Energy efficiency and durability
We plan to use Obdyke Hydrogap between the hardie board siding and the Zip wall. Will that be an adequate drainage plane? or are furring strips also needed?