What would you do?
Here’s the question: All things being equal, would your recommend to insulate a 2×6 exterior wall with R20 closed cell spray foam insulation at approximately 3″ leaving the remaining wall empty or fill the wall with cellulose (or other fluffy type) insulation. For sake of argument, lets stipulate the following:
-From the exterior: wood siding with WRB, Huber zip wall taped, 2×6 frame, board and plaster
-Wall is reasonably air sealed at the exterior sheathing
Please provide you answer and reason why.
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