Opinions on This Wall Assembly
Hi! Thank you for your help in advance. I am seeking an opinion regarding a wall assembly (New York Zone 5). The area is a basement (rather a walkout, please see a picture) build out of cinder blocks. Cinder blocks are covered with tar paper (only half of the wall fully below grade). Looking at 70 years old walls, I can tell that mold (perhaps some water) has entered the area in the past. I have not seen it in a liquid from (perhaps it is more like sweating and dampness), but cardboard boxes left on the slab disintegrated (perhaps it is coming from the slab). Photos of walls and what is behind them attached (wood paneling is 30 years old, not sure about the drywall).
I am considering building a french drain (is it necessary?) inside of the house and staple a dimple mat directly on the tar paper so the water can escape to the drain. Next I am considering foam boards (perhaps FOAMULAR NGX which can supposedly get wet, according to the manufacturer), planning to spray foam sill plate\rim joist area. Then I would like to build studs and likely rockwool in between them. Will top it with drywall and paint. Will do 6 mil poly on the slab before laying a vinyl floor. Obviously, waterproofing is done best on the outside, but this is cost prohibitive and not in consideration. Not expecting miracles. Trying to apply the best solution possible while keeping a cost somewhat reasonable, and not ending with a major mold problem. At the end, I still plan to install a central dehumidifier as part of HVAC system (as mentioned I would like to utilize the space as a living area, not “just” basement), but would like to minimize the “wet problem”.
· Any red flags regarding the aforementioned wall assembly? Am I missing anything?
· Can the foam boards get in contact with the concrete slab at the bottom or should I have some other material between them?
· Floor joists rest on cinder blocks, hoping that air space crated by the dimple mat will not lead to mold production and then floor joists rotting, any concerns here? Second story is a brick as you can see (there is no flashing etc.)
GBA Detail Library
A collection of one thousand construction details organized by climate and house part