Prevent joint failure and save on caulk by backfilling large cracks and gaps with the Caulk Backer Rod. The rod keeps the caulk bead from sinking into the gap, provides additional insulation, and helps prevent air infiltration. The flexible, closed-cell polyethylene foam material is available in 20-foot rolls and is 1/2 inch in diameter. One roll is enough to fill around a standard 32-by-48-inch window. Suitable for windows, doors, pavement, walls, and foundations. DAP | 888.327.8477 |