Hydrophilic Volcanized Expanding Rubber Band

FOX SWELLING TAPE 520, is a flexible waterstop tape based on chloroprene rubber and hydrophilic resin that swells when in contact with water.

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Usage Areas

  • In the joints of ready-mixed concrete elements,
  • In construction joints in reinforced concrete structures poured in place (cold joints where the curtains meet the foundations, etc.),
  • As a watertight flange at the inlets and outlets of pipes passing through reinforced concrete,
  • In tunnel segments,
  • In the joints between the slab and the pile foundation caps,
  • It is used in concrete and steel joints.


  • Easy to apply.
  • It is economical.
  • Expansion continues up to 500% in contact with water.
  • It has a protective coating that prevents premature expansion. FOX SWELLING TAPE 520 starts swelling later than standard inflating tapes. Under normal conditions, the onset of swelling is 7 days after contact with water. This prevents the product from swell in the construction site environment when it encounters undesired water (such as rain). In addition, at the first contact with the fresh concrete, the concrete will swell before it starts to set due to the effect of the concrete water, thus preventing the formation of an unwanted gap between the concrete and the swelling band.
  • It is flexible, can be applied to irregular substrates.
  • It expands in contact with water in reinforced concrete, including concrete elements, and forms a leak-proof seal.
  • It has the property of expanding when it comes into contact with water again.
  • Wide range of resistance against chemicals.
  • Resistant to petroleum products, minerals, vegetable oils and greases.
  • FOX SWELLING TAPE 520 is impact resistant.
  • It is suitable to be used in polluted / slurry waters in areas where the water level rises and falls.