Build A Better Building Envelope with Air & Water Barriers from PROSOCO

Proven to withstand extreme weather conditions, Air & Water Barriers from PROSOCO R-Guard builds more durable, resilient and sustainable buildings.


All components in a wall assembly must work together as a system. That’s why we recommend (as do most building codes) a systems approach to protect your entire building.

Discover our favourite PROSOCO products below and start building more durable, resilient and sustainable buildings today.

Cat 5 Air & Waterproof Barrier

Cat 5 is a primary air barrier that’s applied with a sprayer or roller to above-grade structural surfaces prepared with Joint & Seam Filler and FastFlash. This product produces a highly durable, seamless, elastomeric weatherproofing membrane on exterior sheathing, CMU backup walls, and precast concrete. Proven to prevent water and air penetration of the building envelope in conditions ranging from everyday to the 155-mph winds of a Category 5 hurricane.

FastFlash Liquid flashing membrane

FastFlash is a liquid flashing membrane available in gun or rollergrade. Use it in rough openings, to fill joints and seams, to counter-flash waterproofing and air barrier components in new or existing wall assemblies, and to seal around penetrations. You can also use FastFlash independently or with compatible R-Guard products to prevent the unwanted movement of water and air through building envelopes.

FastFlash by PROSOCO

Fiber reinforced Joint & Seam Filler

Joint & Seam Filler is designed to fill openings and create transitions. This is required to bridge larger gaps and provide continuous support of fluid-applied flashing membranes, waterproofing or air barrier components.