insulating 1×8 pine decking roof
Dean Manoogian| Posted inEnergy Efficiency and Durabilityon
Portland, Maine.The walls and roof of my 1950 cape home are sheethed with 1×8 pine boards (interesting as they came from the foundation form after it was poored for the house). There are 1/4 inch spaces between these boards. I’ve been through the benefits drawbacks and this will be a sealed hot roof. The roof is 2×6″ rafters, 2″ rigid foam with cellulose blown behind. Regardless of my labor and cost, would it be beneficial to caulk these spaces in the walls and roof ? I am doing all of the work accept blowing in the cellulose and having lots of help with info from the contractor but also getting second opinions with many methods.
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Replies
Dean,
It sounds like you are installing 2 inches of rigid foam under the rafters, and blowing cellulose directly against the roof sheathing.
If you have been following my blogs, you know that this method is a code violation -- but still often done.
If I were you, I would install the foam first. You could either hold it back from the roof sheathing with 1x1 sticks, to create ventilation channels, or you could install narrow pieces of foam tight to the roof sheathing, with the perimeter of each piece sealed with caulk or spray foam. That is very fussy work, but much less fussy than caulking the crack between each roof sheathing board.