Sika has a variety of chemical resistant waterstop produced by Westec. Westec was established in 1994 to address a specific need in the industrial construction industry: chemical resistant waterstop and related products for secondary containment areas.

Westec has pioneered products and technologies for sealing secondary containment structures required in the petro-chemical and industrial facilities. Westec continues to provide the highest quality products and expert support for this critical segment of the industry.

Westec has a history of service and innovation in the secondary containment industry. With the Expansion Board Cap seal, numerous retrofit profiles and custom profiles, we develop products with the contractor and engineer in mind. These profiles, combined with the excellent technical support, material takeoffs, shop drawings and jobsite training, make Westec and Sika, the first choice for Secondary Containment waterstop.


WESTEC's Envirostop™ TPE-R (Thermoplastic Elastomeric Rubber) 600 Series Waterstops resist a wide range of oils, solvents and aggressive chemicals and are not readily soluble in any common solvent. Alcohols, ketones, glycols, esters and aqueous solutions of acids, bases and salts have little effect on WESTEC TPE-R Waterstop. TPE-R will swell in aromatic solvents, halogenated organic solvents and hot petroleum oils. Featuring excellent ozone resistance, low temperature flexibility and excellent high temperature (up to 257° F) performance. Our synthetic rubber is heat weldable for easier and higher quality field splicing.


WESTEC's Polyethylene Waterstop is an excellent alternative in an industrial, commercial or roadway application with chemical exposure to hydrocarbons, acids or bases. It is resistance to a wide range of chemicals including hydrofluoric acid. Featuring excellent environmental stress crack resistance and flexibility (flex fatigue), with no failure after one million cycles. WESTEC PE waterstop also has very good low temperature resistance.

WESTEC PE waterstop is not recommended for use with oxidizing acid such as nitric, chlorosulfonic and fuming sulfuric. WESTEC PE waterstop is generally insoluble in organic solvents at temperatures below 122° F. At higher temperatures it is soluble in hydrocarbons and halogenated hydrocarbons.


WESTEC's Stainless Steel waterstop is an alternative for use in severe chemical and high temperature containment applications.