BENTOSEAL Flexible Construction Joint Sealer

BENTOSEAL Flexible Construction Joint Sealer

BENTOSEAL is a flexible joint sealer, providing a permanent water barrier by expanding after contact with water.
This hydrophilic material is designed to be suitable for application to reinforced concrete construction and segment joints.

BENTOSEAL is a delayed hydration, active sodium bentonite, butyl rubber strip.


  • Eliminates split-formwork, splices and welding.
  • Seals voids permanently.
  • Flexible, lightweight and contours irregular concrete surfaces.
  • Suitable for both hydrostatic and non-hydrostatic conditions.
  • Will adhere to concrete, steel and PVC pipes.
  • Unaffected by extreme temperatures(-10°C to +50°C).
  • Unaffected by overnight ponding.
  • Resistant to acids >pH3.
  • Supplied in different dimensions. Easily installed. Adhesive only required for vertical application.


Specific Gravity: 1.57 ASTM D-71
Flash Point: 180°C ASTM D93-97
Colour: Red Oxide or Black
Penetration: 150 GTL 5.8mm
300 GTL 8.5mm
(GTL=gramme total load) ASTM D-217
Expansion: 1 day


7 days


15 days



BENTOSEAL should be fixed to the inner side of the row of reinforcement nearest to the active side of the concrete.

Surface must be clean and free from free-lying water.


  • Apply one coat AD-1 Adhesive to vertical surfaces at the rate of about 30m/litre (1mm wft) over entire surface to receive BENTOSEAL. Concrete nails may also be used.
  • Allow adhesive to dry for 10-15 minutes, but do not allow it to pass the tacky stage or it will have to be reapplied.
  • Remove release paper and firmly press entire length of BENTOSEAL onto the construction joint.
  • Tightly butt ends together to form a continuous waterstop. Do not allow overlapping.
  • Place in maximum practicable lengths to minimise joints.
  • Do not leave BENTOSEAL in permanent contact with water for an extended period of time prior to placing the concrete.
  • Should BENTOSEAL exhibit considerable swelling prior to confinement in the joint, it must be replaced. This swelling will only occur when the placed BENTOSEAL is in permanent contact with water in excess of 8 hours.

BENTOSEAL is supplied in cartons containing 6 coils. Each coil is supplied in the following sizes:-

  • 18mm x 25mm x 5m (total 30m) for insitu concrete construction joints.
  • 10mm x 20mm x 9m (total 54m) for precast concrete segment joints.

BENTOSEAL should be stored in a dry location, away from excessive heat or cold. Shelf life is at least one year in original, unopened packing.

This product is hazard-free, though consumption is not advised. As a standard precaution, it is best kept away from children.