Sealing basement slab before installing carpet tiles?
My husband thinks we need to seal our basement floor before laying down carpet tiles (either FLOR commercial closeouts or Milliken Legato tiles).
I've looked into RedGard and RadonSeal, but I'm stumped with what to do next. I want to do it right, but I also don't have a ton of money to spend on this space, which primarily will be a playroom for our four young children.
The house is 40 years old and had previously had wall-to-wall carpeting with pad, which we ripped out after a sink overflowed. Then we discovered the floor had been laid previously with some sort of tile because we can see the old black adhesive on the concrete in the shape of tiles (I'm guessing it was vinyl tiles).
When we moved in a year and half ago, we passed the radon test, but we do live in the Midwest with thick clay soil, so radon is always a risk.
I did tape down two one-foot sheets of plastic in different areas and had no condensation (although both were done over the black adhesive residue). But the basement does feel damp in the summer, and we do have a sump pump on the other (unfinished) side of the basement.
Any guidance is greatly appreciated.