GCP Applied Technologies (“GCP”) PERM-A-BARRIER VPL 50RS Membrane is a fluid applied, one component, STPE vapor permeable air and water barrier. When applied to approved construction surfaces, PERM-A-BARRIER VPL 50RS liquid is designed to cure and form a resilient, monolithic, fully bonded elastomeric sheet, and to create a continuous barrier against air infiltration and exfiltration, reducing associated energy loss and condensation problems.

PERM-A-BARRIER VPL 50RS Membrane is specifically designed to provide superior protection against the damaging effects of air and liquid water ingress on the building envelope. Vapor permeability allows the wall to breathe and dry, minimizing the risk of water vapor from being trapped and condensing within the wall. While PERM-A-BARRIER VPL 50RS Membrane is vapor permeable, it is impermeable to liquid water, allowing the material to act as a water drainage plain within the wall.

Typical Vapor Permeable Air Barrier Membrane Application. Drawings are for illustration purposes only. Refer to gcpat.com for specific application details.

Product Advantages

  • Fire resistant – meets NFPA 285 as part of various wall assemblies with foam plastic insulation 
  • Formulated without phthalates and halogens
  • Air tight – designed to protect against air passage and associated energy losses. Meets ASTM E2357 standard
  • Vapor permeable –  minimizes moisture from being permanently trapped in the wall cavity by allowing the wall’s ability to “breathe” and dry
  • Single component –  fast and easy application with simple roller or spray equipment
  • Fully bonded – helps transmit wind loads directly to the substrate 
  • Seamless –  continuous membrane integrity with no laps
  • Damp surface tolerant –  can be applied to damp-to-touch surfaces that are free of liquid water
  • Adheres to properly prepared clean common construction substrates such as wood, block, concrete, OSB, and gypsum sheathing