Zip R Sheathing – Climate Zone 6
I received great feedback from my question about crawl spaces so I’m back with another question. Building a new home in Vermont (Climate Zone 6) and learned that Vermont Efficiency program now requires R9 (2″) exterior rigid insulation. I was planning on using the Zip R6 ( 1 1/2″ rigid insulation) which has been standard practice in the area, but it now doesn’t meet the requirement. The Zip R9 (2″) is problematic because the sheathing is too far from the studs and does not provide adequate structural shear bracing resulting in a wobbley frame.
Two alternative methods were suggested:
1) attach 1/2″ plywood sheathing directly to studs for structural sheathing and then mount Zip R9 panels onto the plywood. Add rainscreen detail onto the Zip R9 panels
2) attach Zip R6 (1 1/2″ rigid) to the studs and then add 1/2 – 3/4″ rigid insulation on the sheathing face of the Zip panel and building wrap over the added rigid insulation. Add rainscreen detail over the assembly above.
My gut is that option 1 is better but I would appreciate any/all feedback and comments you might have.
Thanks in advance . . . . I love this forum!
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