Zone 3 minimum wall assembly
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New construction proposed 2×4 wall assembly.
Latex paint, 1/2″ Sheetrock, BIB fiberglass, OSB, Tyvek wb,1″ gap, stone or smart siding.
Doesn’t this just meet the minimum requirements in Zone 3?
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Nope! Doesn't make code min for zone 3 per IRC 2015:
http://codes.iccsafe.org/app/book/content/2015-I-Codes/2015%20IRC%20HTML/Chapter%2011.html
It would make it if it were 2x6 though. Code min is 2x6/R20 or 2x4 / R13 + R5 continuous insulation.
Thanks, Dana!
Just an fyi it depends on your state. My state (Georgia) follows 2012.
Unless otherwise specified in the question, I always default to the most recent version, which is currently IRC 2015.
If you're looking for IRC rev (if any) that applies to your state see:
https://www.energycodes.gov/sites/default/files/images/residentialStatus_0.png
https://www.iccsafe.org/wp-content/uploads/State-Local-Code-Charts.pdf
Wish I knew why Georgia won't move to 2012 IECC. I guess the GAHB is balking at the min r-value for walls which requires them to drop their customary wall mock up (16" oci 2x4 /OSB/Housewrap) for the more expensive 16"/24" oci 2x6 or 2x4 w/exterior insulation.
Frustrating!