# Insulating lean to shed roof?



## Bud9051 (Nov 11, 2015)

Since it is going to be heated I would leave a space above the insulation ans screen in at upper and lower soffits, keep the bugs out.

A vapor barrier never works as an air barrier, too many holes, so the bottom of the rafters needs a complete cover to prevent air from reaching the cold roof.

If your inside activities will be generating a lot of moisture then that air sealing rises to imperative.

Bud


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## cabal2000 (Jun 5, 2017)

Thanks BUD!!
Thats pretty much what I was thinking too. Was really hoping to be able to seal both ends of the joist up but leaving an air space is a far better choice for my environment.


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## Bud9051 (Nov 11, 2015)

It's a small space so will your activities be generating any moisture. Inside a home, cooking, showers, and people produce a lot of moisture. In some environments the moisture problems come from outside like a coastal marine climate. 

Bud


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## chandler48 (Jun 5, 2017)

Bud, would you consider spray foam for the semi flat roof, since there is no air gap like there is between a ceiling and roof? I should think the foam would eliminate most of the problems with air infiltration, moisture, etc. Just checking.


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## Bud9051 (Nov 11, 2015)

Yes, spray foam should be fine, probably should be covered as opposed to leaving exposed.

The real concern is the inside activity. Example, firewood storage can generate a lot of moisture (and bugs). Being a "damp environment here in Newfoundland" it could be best to keep all outside air "out". 

If this will be on a concrete slab a vapor barrier under that slab would be good. Ground moisture can be a problem especially if heated.

OP, will this be heated all winter or intermittently as needed when you want to be out there?

Bud


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