Question

Name this building product: A positive-side waterproofing material with a base of plastic-type clay found primarily in the Black Hills region of the United States.

Answer

Bentonite is composed mostly of sodium bentonite, a nontoxic mineral, and a mix of polymers and other chemicals. When hydrated, Bentonite swells to 10-to-15 times its dry volume. When constrained against a below-grade foundation exterior, its swell capacity is restricted and it transforms into a thick, water-impermeable gel.