Gungrade Polyurethane Waterstop

Product Description

DE NEEF® SWELLSEAL® WA is a single component gungrade hydrophilic waterstop, designed for sealing smooth to very irregular construction joints and pipe penetrations. DE NEEF® SWELLSEAL® WA is supplied in cartridges or sausages. Material cures and swells in the presence of moisture or water. Curing time is dependent on temperature and humidity, i.e. curing time will decrease if temperature and relative humidity are higher. DE NEEF® SWELLSEAL® WA will become firm in 24-36 hours.

Product Application

  • Sealing rough and smooth construction joints of cast in-place or precast concrete in wet and underwater applications.
  • Sealing joints in pre-cast segments in wet or underwater applications (e.g. manholes, box culverts, cable ducts and pipes)
  • Sealing joints between sheet piles.
  • Creating good contact between Hydrophilic Waterstop Strips and rough concrete surfaces.

Product Advantages

  • Solvent free
  • Can be applied to wet surfaces or underwater when concrete is poured within 6 hours
  • Adheres to concrete, PVC, HDPE, steel, & fiberglass
  • Expands to more than 200% of original cured volume
  • Flexible system, adapts to irregular surfaces
  • Easy application with standard caulking guns
  • Good chemical resistance.*

* Chemical Resistance Chart available upon request

Packaging & Handling

10.5 oz. Cartridge 20 oz. Sausage
12 per case 14 lbs 12 per case 25 lbs

Store in dry area for up to 12 months from date of production at temperatures between 40°F and 85°F for best performance. See shelf life details on the material packaging.

Installation Guidelines

DE NEEF® SWELLSEAL® WA should be applied onto a dust-free concrete surface. The surface can be rough or smooth, moist or dry.

Application Method

10.5 oz. Cartridges: Use a heavy duty single cartridge gun. Screw on the nozzle and cut diagonally at the appropriate position

20oz. Sausages: Put the sausage in the empty tube of the bulk caulking gun and cut 1/8 inch o the top of the sausage. Close the tube and install the nozzle. Nozzles are supplied with the appropriate opening.

DE NEEF® SWELLSEAL® WA must be applied in an uninterrupted band (minimum 3/8” bead), gunned in the middle of the joint or precast element. Concrete cover must be at least 3 inches on all sides, in order to avoid cracks from the pressure of material swelling.

If DE NEEF® SWELLSEAL® WA is to be installed under water or during heavy rain, the concrete operation should begin within 2 hours of application to provide confinement for the material or premature swelling may result lowering the effectiveness of the material.

Health and Safety

Always use protective clothing, gloves and goggles consistent with OSHA regulations during use. Avoid eye and skin contact. Do not ingest. Refer to Safety Data Sheet (SDS) for detailed safety precautions. SDS’s can be obtained from GCP Applied Technologies or from our web site at


DE NEEF® SWELLSEAL® WA must be fully conned on all sides to perform properly. When used in precast or joints, minimum concrete cover is 3” on all sides.

If unconfined, material may expand much greater than 200% and develop an open celled structure, which may result in leaks.

DE NEEF® SWELLSEAL® WA is not suitable for surface caulking applications.

When applied at temperatures below 40oF, the material will have a significant cure time, possibly exceeding several days.


Solids 100%  
Vertical Slump 1/8”  
Skins over 6-10 hrs  
Flash Point >266oF ASTM D93
Cured 7 days at 77oF (22oC) 3/8” thick  
Elongation at break 625% ASTM D3574
Tensile Strength 312 psi ASTM D412
Resistance to hydro-static pressure >330 feet of head DNCC
Swelling capacity in contact with water 200% DNCC
Appearance During application: pasty, Cured: rubbery; Color: Gray
  Bead Coverage
10.5 oz. 1/4” 25-35 ft.
  5/16” 12-15 ft.
  3/8” approx. 10 ft.
20 oz 1/4” 50-70 ft.
  5/16” 24-30 ft.
  3/8” approx. 20 ft.