The Brit Adhesives Crack Matting is a decoupling membrane that helps stabilise the floor substrate and the tiles. Decoupling membranes (also known as uncoupling membranes) does just what it name describes: it un-couples, or isolates, the substrate from the tile, allowing them to move independently of each other so that movement in the substrate doesn’t cause the ceramic, stone, or porcelain tile to crack. Decoupling membranes are extremely versatile as they can be used for both interior and exterior applications and can be installed on a multitude of different substrates.