Kerdi waterproofing membrane is an 8 mm (0.20mm) flexible polyethylene vapor barrier membrane that provides uniform thickness. It is composed of a non-woven felt that allows it to be anchored in the mortar. The Kerdi membrane is used to waterproof floors and walls. Its water vapor permeability index is 0.90 perm according to the E procedure at 90% relative humidity. The 6’7"(2 meter) roller covers a wall surface equivalent to the standard height of a showerhead, which limits the number of connections required and thus speeds up installation.