The wedi Building Panel is a waterproof tile underlayment for walls and floors, manufactured by wedi GmbH in Emsdetten, Germany. It consists of an extruded, polystyrene core and is covered in a fiberglass mesh and modified cement resin coating. The blue foam core is closed cell, extruded polystyrene that does not allow the transfer of water and retards water vapor transmission but is not a vapor barrier. The alkali resistant glass mesh adds strength and rigidity to the building panels. The cement coating allows for adhesion as a bonding surface to any standard or modified tile adhesive on cement or epoxy basis. The panel is engineered to be used in interior applications for the installation of ceramic tile, stone or glass tile and various other finishes from stucco to laminates: on walls, floors , countertops and many more applications where traditional backer boards are used. The wedi Building Panel is available in 2'x 4 ', 3'x 5' , 2'x 8', 3’ x 8’, 4’ x 8’ sheets in various thicknesses 1/8", 1/4", 1/2", 5/8", 3/4”, 1", 1 1/4”, 1 1/2" and 2"