Swellable Thermoplastic Waterstop for Construction Joints

VELOSIT WS 804 is a water swellable waterstop manufactured from a blend of proprietary thermoplastics and swelling agents compounded to  produce a re-swellable waterstop of unique swelling ability. VELOSIT WS 804’s delayed swellability makes it suitableis to seal construction joints that will be exposed to rain or water for a few days prior to concreting or joining of pre-cast segments.

Typical applications:

  • Waterproofing of construction joints between pours
  • Waterproofing of saw cut joints
  • Waterproofing of pipe penetrations
  • Waterproofing of wall/slab joints


  • 450 % swelling capacity; fully reversible for an unlimited number of cycles
  • Dimensionally stable; does not wash-out like Bentonite waterstops
  • Delayed swelling; volume increase starts several hours after water contact
  • Swelling pressure resistant to 5 bars (73 psi) hydrostatic water pressures (up to 50 m (160 ft.) acc. to EN 12390-8)
  • Extremely flexible: takes the shape of undulations in underlying concrete
  • Reduced hight reduces pocketing on sides
  • Delayed swellability of 10 to 21 days (depending on temperature) makes it ideal for construction during the rainy season or where repetitive water curing of pre-cast units might be required
  • Colour (Red or Blue) makes it clearly visible


Here you can find detailed information about the selected VELOSIT product.

Technical Data Sheet

Associations & Memberships:

back to top