Foam board between studs and exterior sheathing?
Someone in my area which is located in a zone 5 recently built a small house and sandwiched used 2.5" polyiso between the studs and the exterior wall sheathing. At first I was skeptical but still intrigued. It certainly simplifies window details compared to foam on the exterior. However I guess you would loose some structural rigidity. But would you really loose that much? If the wall sheathing is screwed on over the foam, the friction of the foam against the studs alone should help keep the wall from racking. Also the screw shanks from the studs to the exterior sheathing would also help prevent wall movement. Of course you would want to use the proper amount of foam thickness for your building zone. Would there be a moisture problem where the foam and sheathing interface if they were tight together? I haven't really heard much on this technique so I am sure that there is something that I am totally missing and my friend already totally missed. What do other people think?
Posted Aug 14, 2014 8:20 AM ET
Edited Aug 14, 2014 8:22 AM ET
Other Questions in Green building techniques