Sodium Bentonite is a soft clay of volcanic origin. When exposed to water it expands enormously and can thus be used to provide a water seal for. Bentonite clay is used in the manufacture of geosynthetic clay liners (GSL).Typically a polypropylene geotextile is impregnated with Sodium bentonite. GSL's are supplied in panels and rolls. The matting is not unlike carpet underlay, which can be overlapped and laid on a substrate to form a pond. For larger areas it is advisable to use a specialist contractor. The use of Bentonite was traditional in canal building. It is more expensive than a membrane but tends to be self-sealing and is more conducive to plant growth. It the location of a leak can be detected it is very easy to repair.
Trade Names: Bentomat, Claymat, Volclay, Bentonit
Bentonite is held in a geotextile mat, layed in panels, jointed with clay powder and protected with a layer of sand or soi