Prodeso Eco Uncoupling Membrane is a high quality uncoupling and waterproofing membrane designed for any sized surface. All surfaces must not require expansion joints before tile installation. Prodeso Eco Membrane is 1/8″ thick with a polyethylene top and non-woven thermo-welded polypropylene fabric on the back. Together, both layers make a surface that is both vapor and crack resistant. The Prodeso Eco Uncoupling Membrane was designed to minimize overall floor height and reduce height in transition areas. Prodeso Eco provides uncoupling protection by allowing the tile and substrate to be on different planes. This added membrane keeps cracks from forming on the tile when the sub-floor moves and shifts. The square cavities allow the tile to be securely set and anchored on the polyethylene top. Prodeso Eco Uncoupling Membrane doubles as a waterproofing on top of being an uncoupling membrane from keeping moisture away from the substrate in moisture rich areas such as bathroom, kitchens and entry ways. Is NOT suitable for use on lightweight screeds and outdoor applications.