Thick sectioned, conformable, hydro-expansive waterstop for preventing water entry through joints in concrete sub-structures. The conformable, swellable polymer/ butyl rubber waterstop strip expands in contact with water and when fully encapsulated by poured concrete, the expansive forces form a seal against concrete faces. The seal resists hydrostatic pressure, stopping water from entering sub-structures. Adcor® is a unique product that has been specifically developed to provide higher performance than conventional bentonite or swellable rubber waterstops.


  • Construction joints for in-situ concrete structures.
  • Casting new concrete against existing concrete.
  • Floor slabs cast against diaphragm retaining walls, steel sheet piles and secant piled walls.
  • Joints between floor slabs and pile caps.
  • Remedial 'breaking out' of concrete.

Features/ Benefits:

  • Controlled volumetric expansion - reduces risk of concrete spalling.
  • Conformable - can be installed onto a variety of irregular substrates.
  • Retains cohesive strength at both original and expanded volume.
  • No need for protective steel mesh.
  • Resists at least 6 bar (60 m) hydrostatic pressure.
  • Volumetric expansion min 100% in cement water.
  • Simple overlap jointing on site.
  • Reproducible swell after wet - dry cycling.
  • Can be easily joined to GCP PVC waterstops at movement joints.
  • Unaffected by freeze/ thaw cycling.

System components:

Can be used in conjunction with:

  • Adcor® Mastic: A hydrophilic mastic for use as a bedding bead on irregular concrete surfaces prior to the application of Adcor 500S.
  • Adcor® Adhesive MS: An adhesive for gluing Adcor 500S to smooth concrete, steel and plastic substrates.
  • Pak Adhesive™: A contact adhesive for gluing Adcor 500S to smooth concrete, steel and plastic substrates.

Standard product features


25 x 20 mm.


Light blue.

Technical properties:

  • Volumetric expansion in cement water: >100%.
  • Water pressure resistance (60 m): >6 bar.
  • Density: 1.46 kg/dm³.
  • Weight: 0.7 kg/m.
  • Maximum bend (0°C): 180°.
  • Application temperature: -15 to +60°C.
  • Service temperature: -45 to +120°C.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-75-42/370 Rubber hydrophilic waterstop

NBS Specification

NBS Buliding logo
This product is associated with the following NBS clauses:

Product specification

An important note about specifying



GCP Applied Technologies


+44 (0)1753 490000

Product reference

Adcor® 500S

Secura clips

[Not required]
[Large (25 mm)]

Manufacturer details

580-581 Ipswich Road,
Berkshire, SL1 4EQ
Tel +44 (0)1753 490000
Fax +44 (0)1753 490001
NBS Plus
NBS National BIM Library