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Bumpout Mudroom Insulating and Air Sealing

Nat_T | Posted in General Questions on

This is new construction. I’ve got a small mudroom that projects off of the main building envelope. This bumpout is one story and 6′ x 9′ in plan. See attached for clarity. The building air barrier is zip/tape.

I’m trying to figure out how I integrate this (primarily the roof) into my air sealing and insulation details.

I’m thinking that the roof will need to be treated like a wall in terms of air sealing, i.e. it is not vented and gets air sealed to the main wall. In terms of insulation I would treat this like a hot roof. Does that make sense? If so are there any good details someone can point me to for having overhanging eaves with while maintaining air sealing and how to insulate.  The rafter tails seem very tricky to seal. Is blocking between each rafter and spray foam the solution?

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