Water Cut-Off Mastic (1/10th Gallon Tube) – Ultimate Secondary Seal

Ensure a leak-proof finish on every roofing project with our high-performance Water Cut-Off Mastic. Specifically designed as a secondary compression seal, this mastic is an essential component for EPDM, TPO, and PVC membrane installations.

Unlike standard sealants, this "grey death" (as the pros call it) is engineered to remain permanently non-skinning and flexible. It creates an impenetrable barrier when compressed between a membrane and a smooth surface, such as a wall, curb, or drain flange.

Key Features

Superior Adhesion: Bonds instantly to EPDM, TPO, PVC, metal, wood, and concrete.

Non-Skinning Formula: Stays tacky and flexible indefinitely, allowing it to maintain a seal even during building expansion and contraction.

Weatherproof Barrier: Provides a high-pressure compression seal that prevents water migration behind the membrane.

Easy Application: Packaged in a standard 1/10th gallon (approx. 10.1 oz) tube, compatible with any standard caulking gun.