MAPEI’s Mapeproof sodium bentonite waterproofing membranes have been proven, worldwide, to be the most consistent and reliable products of their kind. Certified as manufactured in accordance with ISO 9001, both Mapeproof HW and Mapeproof SW are constructed using a layer of woven and nonwoven, puncture- and tear-resistant polypropylene fabrics. Encased within these fabrics is high‐swelling, self‐sealing sodium bentonite; loaded at an industry leading rate of 1.1 lbs. per sq. ft. (5.3 kg per m2), minimum. The process by which the sodium bentonite is encased within these fabrics ensures that, regardless of hydration cycles and/or the geometric plane in which it is installed, the membrane will perform as designed.