Warmup’s 3-ply waterproof membrane protects floors and walls under thin-set tile installations from substrate cracks and moisture migration. It is comprised of 2 outer polypropylene layers and one inner polyethylene waterproofing membrane and exceeds testing requirements per ASTM 118.10. The kit includes a 35ft roll of 5”-wide membrane, along with 2 outer corners and 6 inside corners to complete waterproofing in most common bathrooms under 100 sqft.