Quote:
Originally Posted by S-F
I suggest you get some recycled polyiso, cut it to fit the cavities and spray foam it in place. That will give you a good air seal and an immediate R 16. Then I'd Larsen truss to the inside with plywood gussets and 2x3's and dense pack. You could easily get R 40 that way and it would be a lot cheaper/healthier than a full load of spay foam with a much higher R value.
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Even with 2 inches of polyiso I'm not seeing how I can get R16?
Larsen truss is a great idea that is also in the ol noggin for this project. I'm just not sure exactly how much I want to thicken the wall yet.
The current wall is 4" thick (old rough cut lumber). I'd definitely be willing to double that, and I think even add up to 6" (10" total thickness) to the insulation cavity (so drywall = extra). If I did two inches of polyiso foamed in place, and blow the rest in cellulose, that would get me to ~R40.
The other thing is that I do not have 6" to spare in the upstairs. The rooms are already pretty small and the less room I loose the better.