Waterstop RX

Waterstop-RX (also referred to as RX ) is a black coloured flexible strip designed to stop water leaking through concrete construction joints.  A typical application would be to seal the centre of the edge of a poured floor where it meets the footings and base of a concrete or block wall.  The RX is glued into place at least 80mm below top of the concrete pour and then the concrete is poured against it.  Waterstop-RX is comprised of 75% Sodium Bentonite and 25% Butyl Rubber.  On contact with water the Sodium Bentonite expands creating a pressure resistant seal.  Waterstop-RX has been independently tested to withstand 60 metres of hydrostatic pressure.


  • Can be applied to green concrete – thus saving time/money
  • Will conform to uneven or etched concrete surfaces
  • Fast installation
  • Provides a watertight seal around plastic, steel and concrete pipes where they penetrate concrete
  • Ideal for contaminated saline and chemical ground conditions
  • Meets the New Zealand Building Code durability requirements of 50 years