1/2 Cape Cod insulation – how to insulate non standard rafter bays & air barrier for gable vents
I have read most of the articles on here regarding 1/2 cape insulation techniques and cathedral type ceiling insulation methods. I am in zone 5 northern NJ. Cant afford closed cell spray foam. Roof replacement is due and will be performed within the next year. I plan on insulating exterior roof sheathing if i can find a contractor that will do it in NJ.
My plan was:
install 1” firring strips on all 2×6 rafters. Install vent baffles (accuvent product), then install R23 Roxul between rafters, then seal with certain teed smart vapor barrier.
What should I do with the non standard rafter bays. Do i vent them or do i just pack insulation in the rafter bay?
My 1/2 cape has two dog houses in the front of the house. Do i run the vent baffles in the rafter bays under the windows? Do i run vent baffles on the doghouse roof bays, even though there are no soffits?
My house also has an extended family room addition on the back side of the house which means no soffit. Do i run the baffles on those roof rafters as well?
Is an air barrier required behind the second floor ceiling insulation? I am assuming so since there are 2 gable vents on the sides of my house (1 on each side). So i am unsure how/where the air barrier should go. I was thinking of purchasing house wrap, stapling it to the roof rafters above the second floor ceiling/collar ties but below the roof gable vents, then packing the insulation below, then covering interior with smart vapor barrier.
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