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Community and Q&A

Follow-up to cathedral ceiling and Air Krete

Erq3gpjhyg | Posted in Green Building Techniques on

Greatly appreciate your comments. Mr. Riversong: assuming I use the dense-pack cellulose and a 1 1/2″ air-vent (or similar) on my 10″ rafters, I won’t come up with the R-30 required. Do you know of a “green” product that I can use instead of drywall for the ceiling that will give me a little extra insulation, an air barrier, and a finished appearance, even if I have to use a board-and-batten approach? Thank you again.

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  1. GBA Editor
    Martin Holladay | | #1

    I suggest that you install a layer of foil-faced polyisocyanurate foam under the rafters, 1 in. or 2 in. thick, held in place with 1x3 furring, 16 in. o.c., screwed through the foam to the rafters. The foil-faced air space between the foam and the drywall ceiling will provide additional R-value.

    The cellulose can be installed through holes in the polyiso. These holes can later be sealed with canned foam.

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