0800 422 692

Controlled expansion waterstop

Swellstop is a highly versatile, strip-applied waterstop for non-moving concrete joints. Formulated to encapsulate hydrophilic materials into a rubber base, Swellstop creates a controlled, moisture-activated, compression seal.

Swellstop’s structural integrity conforms well to the underlying substrate and exhibits self-healing properties when needed. Unlike many traditional clay-based products, Swellstop will not expand to a point at which the waterstop itself is destroyed.

In-field experience has proven that products, which continually expand, lose much of the structural integrity and can actually erode when subjected to a constant flow of water. Furthermore, the controlled expansion properties engineered into Swellstop, reduce the internal pressures created in cast-in-place applications which can cause spalling in foundations and wall structures.

Features and Benefits

  • Easy to use
  • Effective expansion properties
  • Reduces the internal pressures created in cast-in-place applications


1. Swellstop is installed in and along the joint after the first concrete pour and just before the second pour.

2. A keyway may be formed with a slight draft angle at the joint face to accept the Swellstop, this will reduce the risk of the profile shifting during concrete placement. This may increase the chance of Swellstop being exposed to pooling water.

3. The concrete surface should be smooth and dry, and cured for a minimum 24 hours prior to application of Swellstop.

4. Brush apply a 5cm wide coat of Swellstop Primer Adhesive along the joint and allow it to dry for two hours before application of the Swellstop waterstop.

5. Press Swellstop firmly and continuously in place over and along the primed area. Swellstop can be mechanically fastened to concrete using concrete nails in vertical or overhead applications. This should be done in addition to using the primer adhesive. Suggested fastener spacing is approximately 30cm on center.

6. Swellstop should be spliced by butting the ends together with no separation and no air pockets. Do not overlap the ends of the waterstop.


Swellstop is installed in and along the joint after the first concrete pour and just before the second pour.

  • Swellstop should be used in below grade, non-moving joints only and is not appropriate for expansion joint applications
  • Cracking and/or spalling of the concrete can be caused by the expansion pressure of Swellstop. A minimum 5cm of concrete coverage is recommended. Increase this coverage if using lightweight or low strength concrete (<3500 PSI compressive strength)
  • Swellstop required the presence of moisture to initiate and maintain expansion. The expansion process begins immediately when Swellstop contacts water.
  • Swellstop Primer Adhesive and Swellstop Waterstop should be applied on the same day.
  • Inspect Swellstop for premature swell, discontinuity, and debris contamination immediately prior to the 2nd concrete pour. If swelling and/or damage has occurred, remove and replace the material with new.
  • Do not remove separation paper from Swellstop until just prior to the 2nd concrete pour.
  • Store material in a cool, dark, dry environment.


contact us

Interested in this product?

If you think this product meets your projects needs then get in touch with us to discuss how we can assist you.

Contact us

Keeping you in the loop

Join our mailing list

Something went wrong while submitting the form. Please try again.