Hi, Pulling up all loose vinyl flooring due to mold growth underneath. Huge mess and a big basement. How should I treat moldy concrete slab prior to tiling. What is the best Tile to use on a damp concrete slab, Ceramic or Porcelain. I read I should use an uncoupling/waterproof membrane under layment but I also read to apply the tile directly to the concrete to allow natural moisture evaporation through grout lines.