R-Guard Vapor Barrier (VB)

PROSOCO R-Guard Vapor Barrier (VB) is a fluid-applied air and water barrier formulated for wall assemblies that require a vapor-impermeable membrane rather than the vapor-open behaviour of Spray Wrap MVP or Cat 5.

What it does

It sprays or rolls on and cures into a continuous, seamless STP membrane that simultaneously blocks bulk water, air, and water vapor — appropriate for cold-climate or specialty assemblies where assembly drying needs to happen to one side only.

When and where to use it

• Above-grade walls requiring a vapor-impermeable AWB
• Cold-climate assemblies designed to dry to the interior
• Specialty assemblies (cold storage, controlled environments) needing tight vapor control
• Exterior gypsum, OSB, plywood, CMU, and cast concrete substrates

Key benefits

• Combined air, water, and vapor barrier in one product
• Seamless application — no laps or fastener holes
• STP chemistry — bonds to damp substrates, cures in wet weather
• Compatible with R-Guard Joint & Seam Filler and FastFlash detail components
• VOC compliant

Format

Sold in standard R-Guard pail formats. Confirm assembly direction-of-drying with your designer before specifying — the wrong vapor strategy in the wrong climate can cause problems.