The PERM-A-BARRIER® VPS 30 (vapor permeable sheet) is a primerless, vapor permeable air and water barrier membrane consisting of a proprietary breathable carrier film with a specially designed adhesive. This unique membrane provides superior protection against the damaging effects of air and water ingress on building structures. It creates an effective barrier against air infiltration and exfiltration, which reduces associated energy loss and condensation problems through the building envelope.

The PERM-A-BARRIER® VPS 30 membrane is ideal for wall assemblies that require a breathable air barrier. It permits the diffusion of water vapor that might otherwise condense in the wall structure. The membrane is impermeable to water, enabling it to also act as a water drainage plane.

Advantages

• Primerless, self-adhered sheet - Reduces installation time 
• NFPA 285 - Meets NFPA 285 as part of various wall assemblies
• Airtight - Protects against air passage and associated energy loss
• Vapor permeable - Minimizes moisture from being trapped in the wall cavity 
• Water resistant - Resists wind-driven rain
• Controlled thickness - Factory-made sheet ensures constant, non-variable site application
• Lightweight - Allows for easy handling and installation
• Flexible - Conforms and bonds tightly to inside and outside corners following exterior building profiles
• Strong adhesion - Forms a tenacious bond to prepared construction substrates 
• Compatible with GCP PERM-A-BARRIER® flashing systems
• Wide application window - Surface and ambient temperatures at 25° F (-3.9° C) and above