Dense pack cellulose OVER closed cell foam in cathedral ceiling?
I am considering the following roof assembly in climate zone 4a: Will i run into code or condensation issues?
Single plane roof 3/ 12 pitch
1) 6×10 timber rafters 4′ OC
2) 2×6 T&G decking perpendicular to and OVER (not pieced in between as a cosmetic ceiling) 6×10 rafters
3) 2×4 sleepers, 4′ OC, parallel to 6×10 rafters on top of T& G decking.
4) 2×10 boards perpendicular to and resting on top of 2×4 sleepers, 2′ OC.
5) 2″ closed cell applied from outside to top of 2×6 T&G. The 2×4 sleepers hold the 2×10’s off the T&G so the foam will be continuous underneath/prevent thermal bridging.
6) 5/8″ cdx plywood over 2×10’s
7) 30# roofing felt over plywood.
Cut holes through roof felt and apply dense pack cellulose to remainder of cavity on top of foam.
8) seal holes/patch felt
9) install metal roofing over roof felt directly or on 1×4 sleepers.
drawing of assembly attached
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