I have a 2x6 knee wall under a 2 story addition we recently added to my house. The knee wall is 3 feet high around the perimeter and carries the floor joists. We built the knee wall out of regular 2x6 wood, not p.t.. We covered the outside with cement board, which I stuccoed to make look like real foundation. The inside of the cement board gets condensation and the condensation drips down onto the sill of the knee wall and I am afraid it will eventually rot the sill and knee wall. The condensation seems to occur only on the coldest months of the year.
I know that there are numerous things we could have done better when building this knee wall, but I am looking at options other than tearing out the cement board and then doing it correctly with plywood, tyvek, and a drainage spacer. I was wondering if I coat the inside of the knee wall with a tar paint if that would seal the wood and the cement board and prevent any rotting issues. If I did this would it smell? Any ideas?
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