Insulate/water proof interior stem wall ?
Hello GBA community. I am adding an addition to my existing raised ranch house in climate zone 5. The addition consists of 3 concrete slab levels. I plan on adding R-10 rigid foam to the exterior perimeter stem walls (on both sides). The exterior is also getting self adhering waterproof membrane and dimple mat.
Should I also consider doing anything regarding waterproofing or insulation on the interior stem walls ? In the attachment, #1 is slab on grade (rock ledge) of master bedroom, #2 is an elevated slab 1′ 10″ higher than slab # 1 and equal height to existing home subfloor (floor joist over crawl space), and elevated slab # 3 is 1’10” higher that existing home subfloor.
Essentially Slab # 1 (master bedroom/ bath) will be below slabs #2 & #3. I don’t expect any issues with high water tables or water intrusion.
Hope this is enough info, and if not, I will gladly submit additional info.
Mike – Hudson Valley, NY
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