SwellSeal Waterbar is an extruded rubber compound made from butyl rubber, hydrophilic resin, polyethylene, silicone and special admixtures. It is used to seal joints on many poured-in-place and below-ground precast concrete applications.
SwellSeal produces a water-tight seal when under conditions of confinement as it moulds itself to the surrounding surfaces. On contact with water it is capable of swelling up to 4 times its own volume, even fillings gaps which are uneven in size. This means SwellSeal can be used without the need for any high-compression force.