Conditioned attic approach – open cell & Rockwool?
I’m building a new home and will be doing a conditioned attic space.
I’ve done a little reading about conditioned attic spaces and some notes I’ve jotted down include:
* Since I’m in climate zone 2, it’s recommended that open cell foam be used for the rafters. I heard OCF is “breathable” and acts as an air sealer.
* I’ve read about “flash and batt”, but it appears this usually involves closed cell foam (not open cell foam).
* I heard you want to try to get around R-38 in your attic in this climate zone 2.
* Rockwool is fire resistant.
My rafters are 24” OC, 10” deep.
Assuming the notes I jotted down are true, I was thinking about doing 6” OCF and 4” Rockwool batt (maybe blown in mineral wool?), I believe this will get me close to r-38 in the attic rafters.
Does anyone see problems doing a “flash and batt” with this configuration? I don’t know enough about the physics of either product so thought I’d ask a group who is much smarter about this stuff.
Thanks for your thoughts.
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