Swellseal Mastic WA adheres to concrete, PVC, HDPE, steel, fibre glass, etc. In contact with water Swellseal Mastic WA will expand to about 200% of its original volume. Flexible system, which adapts to the irregular surface of the substrate. Easy application with a standard caulking gun. Durable: will exceed the constructions life. Good chemical resistance. Colossus SwellSeal Mastic WA supplied in cartridges and aluminium sausages