Schluter-KERDI is a bonded waterproof membrane with limited crack-bridging capabilities. It is made of soft polyethylene, which is covered on both sides with a special fleece webbing to anchor the membrane in the thin-set mortar.Schluter-KERDI was developed as a waterproofing membrane to be used in conjunction with ceramic and stone tile coverings. Tiles can be installed directly on Schluter-KERDI using the thin-bed method. Other trowel-applied covering materials, such as plaster, can also be used.Pre-cut sections of Schluter-KERDI are available for inside and outside corners, as well as for pipe collars. Use Schluter-KERDI-BAND, in widths of 5" (12.5 cm), 7-1/4" (18.5 cm), or 10" (25 cm) to seal butt joints or corner joints. Schluter-KERDI-FLEX, in 5" (12.5 cm) or 10" (25 cm) widths, is used to seal expansion joints or flexible edge joints.