Cold Wet Sheathing, Double-Studs WITH Vapor Barrier, or Not?
John’s recent post about open cell foam in a double stud wall here:
…got me wondering about a VERY basic question. The articles linked to by Dana Dorsett refer to this BSC study where double stud wall moisture was evaluated with three different insulation strategies: 12″ cellulose, 12″ Open Cell spray foam, and 5.5″ of Open Cell spray foam.
As I read the articles, I’m understanding that the wall construction is Huber Zip Sheathing -> 12″ Double Stud Wall -> Drywall -> Paint. There’s no mention of a vapor barrier being used… is that the case? They mention specifically that the wall is able to dry to the inside through the painted drywall.
If there’s no vapor barrier being used, is this whole “wet sheathing” scare something that could be avoided by simply using a vapor barrier? Or is there still a concern when using a vapor barrier due only to the concern of potential leakage past the vapor barrier details?