Enjoyed you workshop in Winnipeg recently. You talked about perm ratings for building paper and WRB. I am wondering if there should be any concern about perm rating in a complete wall assembly with OSB, 2" of Styrofoam SM and tyvek. I"m building a house now and I'm planning on doing dense packed cellulose and Airtight Drywall Aproach. Should I be concerned about moisture in the wall assembly and it being able to dry?