Schluter® DITRA UNCOUPLING MEMBRANE 3'3" X 45'9" = 150 SFThe 150 sq ft DITRA roll is the mid size option right for larger bathrooms, open kitchens, and multi room renovations where the 54 sq ft roll runs short but a full contractor roll is overkill. Better cost per square foot than the small roll, less waste than the large one. 1 8" (3. 5mm) polyethylene uncoupling membrane same dovetail cavity system that locks into thin set mortar, preventing tile cracks from subfloor movement 33" wide x 45. 9' long (150