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Best solution to insulate an unvented A-frame ceiling in a finished attic

Virwill9 | Posted in General Questions on

Lacking ceiling insulation, our 1860-era home’s attic/home office gets pretty unbearable most summer afternoons, so I’m looking for a reasonable solution short of installing a modern vented roof, etc. It’s an A-frame with knee walls on the two angled sides. The inside of the ceiling is a combo of exposed wood beams (which directly contact the sheathing) and interlocking wood panels in between the beams(see photos). There’s a 3″-4″ void above the panels, with the roof sheathing above that. 

Everything I read seems to point to filling those voids with air-impermeable insulation, like spray foam, over the sheathing. Is this the way to go? And do all those wood panels need to be removed to do it right? Climate zone: Mid-Atlantic (northern Delaware). Any advice MUCH appreciated. Thanks!

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  1. freyr_design | | #1

    depending on how in need of a reroof you are I would go from the outside unless you are willing to lose the wood ceilings and replace with gyp it will most likely be cheaper and a better system, plus you get a new roof

    also i think you mean air impermeable

    1. Virwill9 | | #2

      Correct, impermeable, fixed. Might be willing to lose wood panels but no need for new roof. Thanks.

  2. walta100 | | #3

    If you are willing to lose some headroom and the current interior finishes, have a look at this article and pick one.

    From the photos the interior looks very nice and expensive to replace. Consider that most people will move before year 7 and insulating that finished space will be expensive and likely have a very long return on investment.


    1. Virwill9 | | #4

      Helpful, Walta. Thanks and please forgive the delayed reply -- on the road. We've been here 12 years and are staying at least 3 more. The summer comfort will be largely worth it, and we think it might help sell the place eventually.

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