Plan for exterior wall construction and insulation
I am planning a new home in PA – zone 6. The options for insulation/exterior wall construction are mind numbing. My wall will be 2×6 single wall construction. I am focusing in on the design plan #5 outlined out in the Dec 2009/Jan2010 issue of FHB. In summary this technique calls for a wall constructed as follows (from the inside out)
2×6 studs with cellulose blown in
two layers of Polyiso Foam (2in per layer/staggered and taped joints)
3/4″ strapping screwed to joists
Here are my questions
1. Is a Vapor Barrier on the interior wall needed?
2. How will this wall handle moisture created inside the home?
3. Are there any repercussions from using two layers of 1.5″ foam vs the 2″?
4. Any repercussions from using sprayed foam vs the blown cellulose?
5. If I use something like Zipwall for sheathing and tap the joints, can I eliminate the housewrap?
and last but not least, considering the fact that I want to stay with the single 2×6 exterior wall and there any other variations on this that I should consider?
I’m sure this question has been raised in manner variations, but I need to ask anyway.
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