Dual Membrane Waterproofing Protection Introduced back in 1987, Swelltite was the first bentonite waterproofing membrane designed for split-slab deck and plaza construction. Swelltite combines the natural waterproofing abilities of Volclay sodium bentonite with a high-strength geomembrane liner for tensile strength and puncture resistance. Volclay Swelltite is a true advancement in waterproofing technology. Unlike other adhered membrane systems which require near-perfect installation, Swelltite’s active bentonite compound can expand to seal small installation imperfections or punctures in the membrane. Swelltite is manufactured at a factory controlled thickness of 90-mils (2.3 mm) assuring the specifier, contractor, and owner of consistent material application. This engineered composite consists of a white 12-mil polyethylene geomembrane liner and 78-mils of bentonite compound with a clear release film applied over the bentonite compound. Swelltite contains virtually zero VOC, can