Proper size selection of CRL Open Cell Backer Rod
is important as it controls the depth of the sealant bead. It must be oversized (50%) to fit tightly into the joint, and function as a bond breaker to prevent bottom-side adhesion of the sealant.
New joints must be cleaned thoroughly, removing any concrete form-release agents, curing compound residue, or any other foreign materials. To ensure a good sealant bond, joints must be clean and dry when the sealant is installed. If old joints are being repaired, all old sealant or filler must be removed. Wire brushing and air blasting are very effective in removing old caulk residues. If an air compressor is used, it must be equipped with traps for the removal of oil and moisture.
After measuring the joint size and choosing the applicable backer rod, install the backer rod at the depth recommended by the sealant manufacturer. The depth that the rod is inserted into the joint should allow the sealant to form a "hourglass" shape. This is the optimum shape factor for prolonging the service life of the sealant. The backer rod must be installed with a blunt tool or roller. The T607CU605 CRL Backer Rod Insert Tool Set
, is designed specifically for the smooth installation of backer rod. Packaged on easy to unroll spools and shipped in boxes not bags.