Bentonite Waterstop

Swellstop Waterstop

Swellstop and Swellstop II are a flexible, coiled strip of butyl rubber and a swellable clay waterproofing compound that swells upon contact with water to form a long lasting compression seal in concrete joints.

Swellstop and Swellstop II also provide excellent secondary protection when used in conjunction with traditional waterstops.

Swellstop requires no special skills and installs quickly. As a strip applied waterstop, Swellstop reduces labor costs by eliminating the need for splitforming and fabricated splices.

Swellstop Advantages

  • Easy to Install - Swellstop can be applied by one person without split forming or splicing.
  • Applies in Any Dry Weather - Swellstop remains flexible under most temperature conditions for all season applications.
  • Safe - Swellstop is non-toxic and requires no special handling.
  • Self Adhering - Swellstop has excellent adhesion to Swellstop Primer/Adhesive over clean dry concrete.

Note: Swellstop or Swellstop II are not expansion joint materials and should not be used as such. A traditional waterstop must be used in expansion or any moving joint. Contact our Technical Service Group for further information.

Typical Applications

  • Construction joints in foundation slabs or below grade walls
  • Precast concrete wall panel system
  • Septic tanks
  • Sanitary and storm sewer manholes
  • Pipe (round, oval, flatbase, eliptical and arch types)
  • Utility and burial vaults
  • Wet wells
  • Box culverts
  • Portable water tanks


A minimum of (2) inches of concrete clear cover must separate Swellstop from the face of the concrete.

Note: In cases of lightweight concrete or insufficient concrete coverage, increase clear cover. Contact our Technical Service Group for additional information.

Swellstop should not be stored exposed to moisture. Should the material become wet during the phasing of the job, check for swell. Should considerable swelling occur before covering with concrete, remove and replace material with new. Use concrete nails to secure the waterstop as necessary.

back to top