I live in zone 6. My main concern in my house assembly is air leakage. My original roof assembly plan was 2 inches of closed cell against the roof deck followed by 9 inches of open cell to reach the needed r value. I was considering what the down side would be of 2 inches of closed cell in the roof deck for air sealing and blown in cellulose in the ceiling to reach the needed r value. Both of these would be unveiled roof assemblies. Any input would be greatly appreciated.
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