Open Cell Backer Rod
This information reflects our best understanding of product composition in 2022.
Backer rods are rigid foam materials used in conjunction with sealants and caulk to fill cracks or crevices between construction materials. Backer rods work by forcing the adhesive into contact with the sides of the joint creating an hour-glass...
Backer rods are rigid foam materials used in conjunction with sealants and caulk to fill cracks or crevices between construction materials. Backer rods work by forcing the adhesive into contact with the sides of the joint creating an hour-glass shape for enhanced bond strength. Backer rods come in two variations, closed and open cell. This CP considers open-cell backer rods, which are less dense than the closed-cell options. As a result, open-cell backer rods can easily compress and restore their shape under mechanical stress; making them more suitable for complex sealing geometries than closed cell. They are intended for use in areas free of moisture. The mechanical elasticity allows for application where heavy movement and/or compression is experienced. The unrestricted air flow, as a result of the open cells, also allows for rapid curing of the sealant, unlike its closed-cell counterpart. Open-cell polyurethane foam backer rods seem to be most common, but open-cell polyethylene foam back rods are also used.