Our waterproof and vapor-proof RedGard? Fabric Membrane is a fast and easy way to prepare the walls and floors of a shower.? It is easy to apply to the substrate, and helps to prepare wet areas such as showers and bathtub areas for tiling.? Use it with the other members of the RedGard? fabric membrane family to cover your backerboard, mortar, wallboard, and slope to provide a durable protective layer for your tile installation.