INSL8 Tile Backer Boards Underfloor Heating Insulation - 1200 x 600mm - Price is Per Board Minimum Order Quantity is 5x Boards INSL8 Tile Backer Boards are a cost effective solution creating a perfect 100% waterproof substrate to tile onto, specifically in rooms exposed to moisture, such as bathrooms, wetrooms, kitchens and laundry rooms. Each board measures 1200 x 600mm, and are light weight which allows for easy handling and installation. INSL8 Tile Backer Boards are made from extruded polystyrene that are coated with a reinforcing layer of glass fibre and polymer-modified cement which provides a stable, durable and waterproof surface for tile installation.