©2015 Green Building Advisor. From The Taunton Press, Inc., publisher of Fine Homebuilding Magazine.
I am planning on building a new house and am looking at using a double wall. Outside wall will be 2x6 studs on 16 centers with ½ plywood sheeting and rain screen. Roxul R24 in cavity’s. Inside wall I will use 2x4 on 16 centers. I will leave a 1 inch gap between both walls. Is this enough or two much? In the 2x4 wall cavities I will install Roxul R14. I have been doing some research hear on the internet and I have read that sometimes the 2x4 studs warp because of no sheeting on the opposite side of the drywall. Can this be a problem and if so can I brace the inside of the stud with strapping or something of that nature? Also I live in Newfoundland Canada so can I use poly as a vapor barrier or one of those new vapor retarders. Also what kind of R value should I expect to get with this set up? Also any problems you know of with this type of wall or precautions I should take. Thanks