Uncoupling / Decoupling membrane is a barrier placed between the tiles and the substrate, ensuring that any movement or cracks are isolated and do not transfer through to the tiles. Thermopanel Uncoupling / Decoupling membrane is suitable for wood or concrete floors, wetrooms or commercial areas, underfloor heating, ceramic, porcelain, stone or mosaic tiles. As the floor moves, the fleece will decouple from the waterproof layer of the mat, allowing the floor to move but not the tiles on top. This helps to prevent cracking. The fleece layer on the Thermopanel Uncoupling / Decoupling matting provides a protective barrier between your tiled surface and the floor susbrate, which will also give you a 100% waterproof barrier as well., Manufacturer: Thermopanel