Backer Rod

Backer rod is a crucial material for joint sealing, crack filling, and expansion joint insulation in concrete, masonry, and window installations. Made from polyethylene or polyurethane foam, it provides a flexible, compressible backing for caulks and sealants, ensuring proper joint depth and improved adhesion. Commonly used in driveways, sidewalks, doors, and window frames, it prevents sealant failure by reducing excessive joint movement. Closed-cell backer rod offers moisture resistance, making it ideal for outdoor applications, while open-cell backer rod allows for better air circulation in interior projects. By acting as a bond-breaker, it improves flexibility and durability in concrete expansion joints, log home chinking, and construction gaps. Available in various diameters and densities, backer rod is a cost-effective solution for ensuring long-lasting, crack-free sealant applications in both residential and commercial construction.