DE NEEF® Swellseal

Product Description

SWELLSEAL® for Sheet Piles is a single component gungrade hydrophilic waterstop, designed for sealing sheet pile knuckles. SWELLSEAL® for Sheet Piles is supplied in 20 oz. 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® for Sheet Piles 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 Applications

Sealing sheet pile knuckles, by application of SWELLSEAL® for Sheet Piles, before driving the sheet piles.

Packaging & Handling

20 oz. Sausage

  • 12 per case
  • 25 lbs.
  • Shelf life is 2 years when stored cool and dry


Solids 100%  
Vertical Slump 1/8"  
Skins over 6 - 10 hrs  
Flash point  > 266°F ASTM D93
CURED 7 DAYS AT 77 °F (22 °C) 3/8” THICK    
Elongation at break 625% ASTM D412
Tensile strength 312 psi ASTM D412
Resistance to hydrostatic pressure > 330 feet of head DE NEEF®
Swelling capacity in contact with water 200 % DE NEEF®
Appearance During application: Pasty, Cured: rubbery, Color: gray During application: Pasty, Cured: rubbery, Color: gray
1/4” 50-70 ft
5/16” 24-30 ft
3/8”  Approx. 20 ft

Installation Guidelines

SWELLSEAL® for Sheet Piles should be applied onto a dust-free surface. The surface can be rough or smooth, moist or dry.

Refer to Installation Instructions for SWELLSEAL® for Sheet Piles.

Application Method

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

SWELLSEAL® for Sheet Piles must be applied in an uninterrupted band, gunned in the female sheet pile interlock.

If SWELLSEAL® for Sheet Piles is to be installed under water or during heavy rain, the caulked sheet pile interlocks need to be protected from rain and water to avoid premature swelling which may result in 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 SDS (Safety Data Sheets) for detailed safety precautions

In the event of an EMERGENCY call:

CHEMTREC 800-424-9300.


SWELLSEAL® for Sheet Piles must be fully confined on all sides to perform properly.

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

SWELLSEAL® for Sheet Piles is not suitable for surface caulking applications.

When applied at temperatures below 40 ºF, the material will have a significantly longer 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