Climate zone 7, Canadian prairies, Cape Cod House
Unvented, unconditioned attic
The sloped part of the roof was spray foamed. Now I want to add roxul mineral wool to the flat attic.
I’m including a picture to show you how the spray foam tapers off at the intersection of the rafters and collar ties.
When I add the roxul (1st layer runs between the collar ties, additional layers run perpendicular) is it correct that it should not touch the underside of the roof sheathing?
If this is true, it seems odd that there will be an uninsulated gap.
The total assembly goes like so: attic side kneewall has 3″ EPS type II, roxul in the kneewall stud bays, closed cell spray foam in sloped part of roof, and roxul batts in flat attic. Is it ok to run smart vapor over the entire thing?
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