Gungrade Polyurethane Waterstop

Product Description

SWELLSEAL® WA is a single component gungrade hydrophilic waterstop, designed for sealing smooth to very irregular construction joints and pipe penetrations. 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. SWELLSEAL® WA will become firm in 24-36 hours.

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

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.


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.

Installation Guidelines

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.

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 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.

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.

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


SWELLSEAL® WA must be fully con ned 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.

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. | North America customer service: 1-877-4AD-MIX (1-877-423-6491)

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation or suggestion is intended for any use that would infringe any patent, copyright or other third-party right.

DE NEEF and SWELLSEAL are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies, Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

© Copyright 2018 GCP Applied Technologies, Inc. All rights reserved.

GCP Applied Technologies Inc., 2325 Lakeview Parkway, Suite 450, Alpharetta, GA 30009, USA
GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6.
This document is only current as of the last updated date stated below and is valid only for use in the Canada. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2023-06-29