Looking for feedback on insulation design for bonus room with "cut and cobble"
On the attached truss drawing, I used pink highlighter to accent the areas of rigid foam. For the knee walls (technically full height) I was planning on using cut and cobble for the thickness of the 2x6s and then a continuous 4" layer of EPS on the inside just prior to drywall. Seams would be staggered and taped.
On the bottom of the bottom chord of the truss I was planning on a continuous 2" layer of EPS.
All attic portions of the truss would be blown cellulose. The bottom 2x12 truss that spans 20' would be blocked at both ends with rigid foam and then dense packed with Spider.
I know most people on this site tend to frown upon cut and cobble, but I think I can alleviate moisture vapor transmission worries with the continuous interior foam. In addition, the cut and cobble would do a much better job blocking air movement from the "attic" as opposed to dense pack cellulose or high density batts. Since there is no sheathing on the backside of the knee wall, shouldn't the wall have the ability to dry slowly in both directions?
In a somewhat unrelated question, do you know how insulation contractors would fill the top portion of the attic? If I install the rigid foam before they come, they would be working blind. I thought maybe insulweb on the ceiling and also at the top of the insulation and they could blow it between the insulweb? Might be very tricky to get the insulweb installed on top.....Thoughts?
Posted Tue, 04/01/2014 - 07:58
Edited Tue, 04/01/2014 - 09:04
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