WATERSTOP-RX® Expanding Concrete Joint Waterstop

Unmatched Protection for Concrete Joints

WATERSTOP-RX® is one of the most efficient and effective waterproofing products available today for preventing water penetration in concrete joints.


There’s nothing else like it.


Low-cost enhancement for improved external waterproofing

For cast-in-place, reinforced concrete structural joints—vertical and horizontal—as well as around pipes and structural penetrations, WATERSTOP-RX® is your most reliable protection against water. Working as an active barrier for structures under either continuous or intermittent hydrostatic pressure, WATERSTOP-RX® substantially reduces the possibility for leaks—its active volcanic bentonite component absorbs up to 15x its volume in water, expanding to seal cracks using the very pressure of the water itself to fill and block any gaps.


WATERSTOP-RX® is available in three size/shape configurations for effective fit in nearly any appropriate construction gap:

CETCO WATERSTOP-RX 101 packaging


  • Size
    1" x 3/4" (25 mm x 20 mm)
  • Roll Length
    16' 8" (5 m)
  • Cross-Section Shape
  • Unit Qty/Carton
    100 linear feet (30 m)


  • Size
    1-1/4" x 1/2" (31 x 12mm)
  • Roll Length
    20' (6 m)
  • Cross-Section Shape
  • Unit Qty/Carton
    120 linear feet (36 m)
CETCO WATERSTOP-RX 102 packaging


  • Size
    3/4" x 3/8"
  • Roll Length
    33' 4" (10 m)
  • Cross-Section Shape
  • Unit Qty/Carton
    200 linear feet (60 m)

Easy installation saves you money

WATERSTOP-RX® is also easy on your budget, saving you money in time and installation. Designed for greater performance predictability, it replaces traditional PVC/Rubber dumbbell waterstops, eliminating the need for special pieces, split-forming, and seams. WATERSTOP-RX® is manufactured in lightweight, flexible coils and can be easily installed by a single worker without extensive training—Simply apply WATERSTOP-RX® to a prepared surface and press it into place.


How it does it

WATERSTOP-RX® features an active bentonite/butyl-rubber construction and has been successfully tested by independent testing firms to over 60 meters (200 feet) of hydrostatic water pressure, under both continuous immersion and wet/dry cycling.


CETCO - Pioneer and leader in waterproofing

CETCO is the leader and pioneer in cutting-edge waterproofing solutions. Around the globe, our innovative teams of clay mineralogists, chemists, and polymer scientists transform ordinary minerals into extraordinary technology to solve day-to-day problems worldwide.



    Architectural Specs
    Case Studies
    In the News
    Sealing Cold Joints with Waterstops - Waterproof Magazine, April 2017
    Understanding Waterstops: To Ensure Success, One Must Specify for Performance, Install with Care - Construction Specifier Magazine, June 2015
    Installing Thermoplastic or Rubber Waterstops - The Construction Specifier Magazine, June 2015