Cistern Waterproofing

Cistern waterproofing is a specialty use case: a continuous, sealed liner on the interior of a structure that holds water for human use. The chemistry matters, because anything that leaches into the water is going downstream into a tap, a livestock trough, or an irrigation line. HydroStop BarrierGuard is the membrane designed for this assembly, NSF P151 certified for rainwater catchment system components and engineered to bond to concrete and masonry cistern walls without compromising water quality.

Reinforce BarrierGuard with HydroStop Fabric (100% polyester) at seams, penetrations, and tank corners to add tensile strength and bridge any movement cracks in the cured liner. Common applications include Caribbean rainwater catchment, off-grid potable storage, and agricultural water tanks. For rainwater-roof topcoats on the catchment side, see Elastomeric Roof Coatings (the WOB variant is NSF P151 certified). Related: Waterproofing Basements, Waterproofing Foundations, Concrete Waterproofing. Factory-direct from a GAF-authorized distributor.