Schluter® DITRA UNCOUPLING MEMBRANE 3'3" X 16'5" = 54 SFDITRA is the industry standard uncoupling membrane for tile and stone floors. It prevents cracking by isolating your tile from subfloor movement wood expands, concrete shifts, and DITRA absorbs it all so your tile doesn't have to. This 54 sq ft roll is sized right for a single bathroom or small kitchen. 1 8" (3. 5mm) thick polyethylene mat with dovetail cut cavities that lock into thin set mortar from both sides Four functions in one layer: