Mastech Waterstop



Mastech WATERSTOP-SW is an expanding waterstop that consists of natural sodium bentonite, butyl rubber and special polymers that expands not only in clean water but also in salt and brackish water. It is a flexible and self-adhering material which expands colloidally in contact with water and applicable to all construction joints.

Areas of Use

Construction joints of the near shore structures in contact with sea water, brackish water prosess tanks, precast elements, water tanks, waste water treatment plants, tunnels, basements, manholes, culverts, reservoirs, swim- ming pools, canals, etc.

Features and Benefits

  • Expands in salt and brackish water
  • Easy to install
  • Flexible
  • Self-adhering
  • Non-toxic
  • Not contain bitumen, tar, asbestos, etc.
  • Needs no special handling


  • 25 mm x 20 mm x 5 m
  • 25 mm x 10 mm x 10 m
  • 25 mm x 5 mm x 15 m
  • 20 mm x 10 mm x 10 m
  • 18 mm x 6 mm x 15 m

* Different colors and sizes are available.

Typical Physical Properties


Black, Blue and all colors are available


≥ 250%

Specific Gravity

1.35 gr/cm3

Hydrostatic Pressure Resistance

Up to 60 m. water column (6 bars)

Installation Temperatures

-15 °C / 60 °C



Surface Preperation

Surface should be clean and dry

Shelf Life


5 years in original undamaged package ***

*** Dry and moisture free environment.