Board Seam Filler

PROSOCO Board Seam Filler WB is a water-based, acrylic, gun-grade joint and seam filler used to prep board-to-board sheathing joints before R-Guard FastFlash or other PROSOCO air-barrier coatings.

What it does

It guns, spreads, and tools easily, bonding to common sheathing materials without a primer and remaining breathable so damp substrates can dry. Once installed, it can stay exposed to weather and UV for up to 12 months before being covered.

When and where to use it

• Filling field seams in sheathing before fluid-applied air barriers
• Building-wide continuous air barrier systems
• Indoor or above-grade exterior application

Key benefits

• Water cleanup — no harsh solvents
• No solvents, isocyanates, or phthalates
• ≤25 g/L VOC, complies with regional air-quality regulations
• Bonds without primer
• 12 months exterior exposure tolerance
• 87% solids, low-shrink cure
• 1-year shelf life sealed

Format

Viscous orange paste in standard PROSOCO containers.