External Waterproofing Solution

We use a self-sealing dual sheet waterproofing membrane manufactured to controlled thicknesses of 150 mils to 200 mils of tough, high density polyethylene (HDPE) and expandable, quality granular bentonite. The bentonite, capable of expanding to 6 times its thickness, is laminated at a rate of up to one pound per square foot to the impermeable HDPE sheet forming a superior Dual Waterproofing System for application to horizontal and vertical surfaces.

•Tensile Strength: Membrane (psi) – 4,000 psi (27.6 MPa)
•Resistance to micro organisms: bacteria, fungi, mold, yeast), Unaffected
•Resistant to hydrostatic headwater
•Extremely high resistance to chemicals & gases
•Life Expectancy: both high density polyethylene and bentonite have life expectancy measurable in thousands-of-years.

 Cornerstone Basement Technologies are specialized in exterior and interior poured & block concrete foundation waterproofing.


This remarkable waterproofing membrane is designed for use on structures above and below grade. It is excellent for use on split slab parking, plaza decks, poured and block foundation walls and earth covered roofs. It has outstanding performance when used under conditions of high water head.