HYDRO BAN Preformed Curb is made from high-density expanded polystyrene with a liquid waterproof membrane coating applied to it. HYDRO BAN Preformed Curb is lightweight and ready-to-tile. Materials: Utility knife or fine tooth saw, latex fortified large, heavy tile mortar (eg. 4-XLT), 1/2" x 1/2" (12 x 12 mm) square notch trowel and HYDRO BAN Adhesive & Sealant.