Prosoco Cat-5 Rain Screen Waterproofing Membrane (5 gal.)

Prosoco Cat-5 is a premium, liquid-applied air and water-resistive barrier engineered for ventilated-cavity rain screen construction. Formulated with a silane-functional polymer, it self-seals fastener penetrations and bridges hairline cracks to deliver a seamless, weatherproof film. Cat-5 bonds and cures on damp or wet substrates—no primer required—so installers can maintain productivity even in challenging conditions.

Ideal for both new-build and retrofit applications, Cat-5 will not tear or degrade under UV and weather exposure for up to 12 months, ensuring lasting protection. If the membrane is ever damaged, simple spot repairs restore full performance.

Key Features

• Silane-functional polymer for superior adhesion, crack-bridging and weathering
• Self-seals fastener penetrations for uninterrupted protection
• Bonds and cures in wet or damp conditions without primer
• Compatible with most common building materials; easy to repair if damaged
• UV* and weather-resistant performance for up to 12 months during construction
• Specifically designed for use under ventilated-cavity rain screens