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Originally Posted by llmonty  Quick question on your insulation for the ceiling -- If I recall you have an unvented roof. Are you only using cellulose in the roof rafters?
I ended up going with an unvented design as well. However, in order to meet the r-value code requirements (recently changed to r-38) and to make sure it is a tight space, 2 different insulation contractors recommended 2" of closed cell foam, followed by 7" of cellulose. On the roof we used standard roofing felt for breath-ability. This is the way I am currently going -- I know the closed cell won't help with sound... |
Are you using 2x8" rafters? We're using 2x12 rafters with furring, so we can do R-38 with cellulose alone.
BTW, it was pointed out to me that it was quite a hack to change the R-value requirements so that 2x12 rafters alone were not sufficient for the required minimums. It's obvious that somebody with a product to sell had a lot of clout to be able to run almost all other competition out of business or force builders to use very unconventional building techniques!