What roof design is better, cheaper, and easier to build?
Currently planning a cathedral ceiling (VENTED) with R80 insulation. Since its vented all the insulation (not sure whether it will be Roxul batts or blown in Spider) will be inside the truss web which will have to be about 26″ deep (to allow for a vent over the 24″ insulation space.
This made me think about an UNVENTED roof plan with rigid insulation on the exterior. With the same goal of R80 in mind can someone please advise me the appropriate layup… and thicknesses required.
and given the two options which is more resilient, less expensive and easier to both build and and work with (I have a wood stove chimney that has to penetrate the roof).
Thanks from Kenora Ontario Canada P9N0E7 (zone 7).
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