HYDRO BAN® Board is a lightweight easy to handle and ready to tile wall board designed to be used in bonded tile or stone installations. It is made with a high-density, waterproof extruded polystyrene core and a reinforced, waterproof membrane on both sides to give triple protection from water and vapor intrusion. Available in a variety of thicknesses from ¼” to 2” (6 mm to 50 mm) the HYDRO BAN Board can be used on walls, floors, ceilings, and in many installations requiring dimensionally sound and stable substrates as well as in steam rooms and steam showers. It does not contain cement, fiberglass or paper products and will not cause itching or create messy cement debris during installation. No tab washers are required for floor and wall installations when using the ceramic coated HYDRO BAN Board  Screws.