Perm-A-Barrier® air barrier system

A comprehensive portfolio of fully-bonded air barrier membranes for NFPA 285 compliant assemblies. GCP technology includes permeable and non-permeable solutions offered as both fluid-applied and sheet-applied systems.

The Perm-A-Barrier® portfolio provides watertight, airtight air barrier systems and full field technical support for flexibility and high-performance compatibility with a project's building envelope design. Broad product range for any wall design or design requirement.  Our air barrier membranes and accessories are designed to work together and are rigorously tested to meet building code requirements. The end result is a truly optimized wall design that's sustainable over time.


Perm-A-Barrier® Product Documents

Product Name Product Data Sheet
Product Data Sheet
Products & Accessories


  • Product Name
  • Description
  • Key Benefits
  • Applications Type

PERM-A-BARRIER® VPL 50 is a fluid applied, one component, STPE membrane that cures to form a resilient, monolithic, fully bonded elastomeric sheet when applied to construction surfaces. PERM-A-BARRIER® VPL 50 membrane is vapor permeable for wall assemblies requiring this “breathable” characteristic. As a vapor permeable membrane, it permits the transfusion of water vapor that may otherwise condense in the wall structure; but is impermeable to liquid water, which allows the material to act as a water drainage plain.

Key Benefits
  • Resistant to early rain
  • Simple application
  • Chemical cure, wet thickness is equal to dry thickness
  • STPE technology
Application Type

Building envelope


Design versatility and performance

The Perm-A-Barrier® portfolio offers both permeable and non-permeable solutions to meet the range of factors on a given project, including regional climate, wall design, compatibility with other materials, insulation placement and interior conditions.

Our newest air barrier Perm-A-Barrier® NPS employs a primer-less, self-adhered application for easier installation that saves time and money on the job. Eliminates primer, oftentimes a hazardous chemical, from the job site.

Perm-A-Barrier® product portfolio

  Impermeable Permeable
Liquid-applied Perm-A-Barrier® Liquid Perm-A-Barrier® VPL / VPL LT
  Perm-A-Barrier® NPL 10 Perm-A-Barrier® VPL 50
  Perm-A-Barrier® NPL 10 LT Perm-A-Barrier® VPO
Self-adhered Perm-A-Barrier® Wall Membrane Perm-A-Barrier® VPS
  Perm-A-Barrier® Aluminum Wall Membrane Perm-A-Barrier® VPS 20 (primer less)
  Perm-A-Barrier® NPS (primer less)  
Accessories Perm-A-Barrier® Wall Flashing Perm-A-Barrier® Detail Membrane
  Perm-A-Barrier® Adhesive Perm-A-Barrier® Aluminum Flashing
  Perm-A-Barrier® Liquid Flashing Perm-A-Barrier® S100

Tried and tested for high performance with code compliance

Most products in the Perm-A-Barrier® portfolio meet or exceed all ASTM, ABAA, and NFPA building code standards. In addition, Perm-A-Barrier® solutions have been tried, tested, and proven across thousands of projects worldwide.

Expert field technical support

Our technical experts frequently provide direct consultation throughout the design, product selection and installation process. In addition to project specific support, GCP provides both classroom and hands-on applicator training to ensure that our Perm-A-Barrier products are installed correctly and perform as designed - protecting the structure for years to come. Able to instruct applicators on the installation of sheet membranes and proper spray techniques, GCP field technicians advise on the proper sequencing and use of materials within these flexible systems. Consult in product compatibility, assembly techniques for a completely water and air tight system.  Offer advice on;  detailing, sequencing, efficient assembly techniques, labor saving tips.