basement insulation
I have concrete basement walls with one wall framed with 2 by 6 on a pony wall. I was thinking of air sealing with chalking and then on the concrete add mineral board as the thermal break. Then for the wood area comfort batt and mineral wool so it is all flush mineral wool. For the floor EPS with two layers of plywood for a floating floor. Then when I am ready to finish framing the walls studs, batt, vapour barrier and drywall. Should this work for water, air leakage and thermal? Wall will be R30 to R50 and floor R15 (as it has 2 inches of xps) under slab. I asked the contractor for 2 inches XPS on outside wall and found out after (I wasn’t around at the time) that there was only 2inches XPS on the footers not the outside wall.
Thank you
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Replies
I think your plan is to caulk to air seal, then install rigid mineral wool panels against the concrete? You want to use insulation that is not vapor open here, which means some kind of rigid foam. If you're already planning to use EPS on the floor, then I would use the same EPS to go up the masonry wall. You can use batts in the regular part of the wall that is above grade, which I think is what you are describing here.
Bill
Thanks Bill
BTW, I wanted to add that mineral wool, rigid or otherwise, is NOT an air barrier, so air sealing between mineral wool and anything else doesn't really accomplish anything. You can use EPS as an air barrier, or drywall, or even plywood/OSB, but not the rigid mineral wool.
Bill