Foam backer board as subfloor?
Ok so correct me if I’m wrong because I’m not a building scientist but isn’t foam backer board basically rigid foam with a membrane coating? So if I were to lay it down on my concrete basement floor I would get insulation, waterproofing, and a base to lay any floating floor I want (carpet tiles, lvp, rubber, etc.) I’m sure it cost more but you wouldn’t need rigid foam and wood for your sub flooring. Plus the floor would be thinner and insulated. I’m probably missing something here because I never heard anyone doing this, is this even possible? If not I would think 1/2 inch rigid with 1/2 inch durock on top would be the same thing but just thicker. I wanted to lay lvp directly on my floor to save ceiling height but I’m not confident enough in my moisture levels. I know I’m annoying with these basement floor questions but it’s for my kids, just can’t take any chance of mold.
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