A great underfloor heating solution for under tile requirements is to use a decoupling membrane suitable for use with electric under tile heating cable. Decoupling Membrane for Undertile Heating Cable: Material: Polyethylene (PE) film top; Polypropylene (PP) non-woven bottom. Weight: 1000g/sqm Thickness: 5.6mm Wire Cable Diameter: 3.6 - 4.2mm Distance of the studs: 4mm Waterproof: Yes Available Roll Sizes: 5m x 1m 10m x 1m 20m x 1m Heating Cable: The drop-down represents 2 different options. Please use the table below to see how much cable you need to fit the space you require. 160W/m2 is used as a primary heat source, 105W/m2 for a warm floor effect. Cable Length 160W/m2 105W/m2 Wattage 10.5m 0.65m2 0.99m2 105W 13.5m 0.84m2 1.27m2 135W 16m 0.99m2 1.5m2 165W 20.5m 1.27m2 1.93m2 210W 27m 1.67m2 2.54m2 265W 32m 1.98m2 3.01m2 315W 40m 2.