ClassicBond EPDM Water Cut Off Mastic

When you're installing an EPDM roofing system, ensuring a proper seal is essential—especially at termination points. The ClassicBond® EPDM Water Cut-Off Mastic is the ideal choice for achieving a strong, reliable seal, whether you’re a professional roofer or tackling a DIY project. This high-performance, single-component butyl-blend mastic is designed to be used with EPDM membranes and other compatible roofing systems where a compression-type seal is required. Formulated with excellent tackiness and low viscosity, this mastic remains pliable even after application, allowing it to maintain its grip under pressure. It's particularly well-suited for sealing between membranes or when a membrane is being terminated using a termination bar or similar compression fitting. It’s also commonly used in parapet wall detailing, where secure sealing is crucial. Each tube covers approximately 3 linear metres when applied as an 11mm bead, which is the recommended size for effective performance. With a working temperature range of -40°C to +93°C and excellent cold-weather flexibility, this mastic performs reliably in all UK weather conditions.

Why Choose ClassicBond Water Cut-Off Mastic?

Strong Adhesion – Highly tacky for dependable sealing performance, even in compression-sealed areas. Versatile Application – Ideal for use with terminations, wall abutments, and parapet walls. Reliable Coverage – One tube provides approximately 3 linear metres of coverage at an 11mm bead. Cold Weather Flexibility – Maintains performance in freezing temperatures down to -40°C. Straightforward to Apply – Suitable for both roofing professionals and DIY users. Shelf Life – Up to 12 months in an unopened container when stored in a cool, dry place.

Application Instructions

Surface Prep: Ensure the area is clean, dry, and free from dust, grease, oil, or moisture. Apply Bead: Run an 11mm bead of mastic between the substrate and the membrane edge. Secure the Termination: Press down and apply the correct termination bar or flashing to maintain consistent compression across the mastic bead. Note: Avoid contact with skin and eyes, and use in a well-ventilated area. The product is flammable—keep it stored away from heat sources or open flames.

Product Details

Type: Butyl-blend mastic Viscosity: 1,320,000 Cps (approximate) Service Temperature: -40°C to +93°C Coverage: Approx. 3 linear metres per tube (11mm bead) Shelf Life: Up to 12 months (unopened) Finish: Black