Spray foaming the attic with a twist
I will be having my attic sealed and insulated with closed-cell spray foam. However, the design of my house makes this a bit more complicated because my roof cuts into the second-story ceilings at the front and rear edges of the house (will make more sense if you look at the attached pic).
Above this part of the ceiling, there is only some very old batt insulation (less than R-8) and the roof deck. The house doesn't have eaves/soffits, so there is no venting in this area.
As shown in the attached pic, the spray foam contractor suggested building up the spray foam to form a sort of mini-knee wall at the edge of the attic, separating the attic from the space above the sloped ceiling.
This approach makes me very nervous because the sloped space will essentially be uninsulated and unvented. I'm not so worried about energy loss as I am about ice dams.
This is in climate zone 5A.
Do I have a valid reason to be concerned? Can I just blow cellulose in this area and seal it up?
Posted Aug 14, 2014 12:19 PM ET
Edited Aug 19, 2014 8:17 AM ET
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