EIFS in combination with interior spray foam insulation
I would like to design a wall system using EIFS stucco with an interior spray foam insulation. I live in north east Colorado which is in climate zone 5. The EIFS eps would probably be 1.5″ over Tyvek stuccowrap wrb, or a similar product. My wall sheathing is 7/16 osb.
On the interior, my walls are 2×6. I would like to apply 1″ closed cell spray foam followed by a kraft faced insulation bat of either R-13, which would leave about .5″ of an air gap between spray in and fiberglass. Or R-19 kraft faced fiberglass which would come in contact with the spray in foam.
I like the idea of the closed cell spray foam adding rigid strength and reducing the air infiltration. Should I be concerned with vapor from the interior getting trapped between the fiberglass and closed cell foam? Usually in the winter, we struggle to keep the interior humidity at or above 30%, but I understand water vapor no matter the percentage can still condense on a cold surface.
What other concerns should I have with this type of system, and how can I improve it? I would certainly appreciate any product recommendations and techniques.
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