6mm Premium Tile Backer Boards – FREE Next Day Delivery The dimensions of each board are 0.75m² (6mm x 1250mm x 600m) Tile Backer Boards are perfect for underfloor and under tile heating applications, and are ideal for 2 main purposes; - 1.) As a waterproof surface to fix wall or floor tiles to. 2.) As a first class heat insulation solution for underfloor heating systems, lowering heat up time and running costs. Premium Tile Backer Board Uses & Features: ---As a first class heat insulation for underfloor heating systems. ---As a superior waterproof surface to fix wall or floor tiles. ---Tile backer boards are particularly suitable for underfloor heating mats and under tile heating cable applications. ---Will accept even the heaviest wall tiles, unlike plasterboard.