With our Warmup Loose Wire System there is no need to dig up the floor and no need to mix concrete. Simply fix our heating element to the subfloor, tile straight over and say goodbye to cold feet for good! There are 4 packs sizes available, the largest pack is the DWS800 which can cover up to 5.9m². Multiple packs can be used together to cover a larger space (up to a maximum of 25m²). For example to cover a flooring space of up to 17.4m² you would use 3 x DWS800 packs. Our Warmup Loose Wire System is best suited for: Ceramic Tile & Natural Stone in small, irregular-shaped areas.