EPS exterior with CC SPF Interior
I am currently pricing out insulation solutions to achieve between R-35 and R-40 for my above grade walls.I am in climate zone 8. I have priced out adding 2 inches of CC spray foam then filling the cavities with fiberglass batts. This also included 0.5 inches of XPS outside to cut thermal bridging. However reviewing that I realize that is creating a sandwich with no path for the moisture to exit. I am still wanting to combat the thermal bridging concern. One spray foam company recommends going to 3 inches to ensure no condensation forms between the batts and the foam.
I am still wanting to cut thermal bridging if I can and am wondering if using 1 inch of EPS instead of XPS, and ensuring a rainscreen is in place would be enough to mitigate the OSB sheathing from being wet all the time?
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