Mapei Mapeguard UM 1 Roll is a waterproofing, uncoupling and anti-fracture membrane for cracked and damp substrates and substrates that are not fully cured before installing ceramic and stone tiles for internal and external surfaces without having to copy the layout of distribution joints in the substrate and allowing moisture in the underlying layers to be released. Mapeguard UM 35 is a membrane made from a layer of honeycomb HDPE with a rough surface and polypropylene fabric backing. These characteristics improve the bond strength of adhesive applied on both sides.