Before Caulking, Use Backer Rod  To Help Fill Gaps And Openings In Pavement Cracks, Wall Joints, Foundations, Sidewalks And Driveways.The Gap Filler Helps Cushion And Insulate And Helps Prevent 3-Point Bonding.
 ▪   Use To Fill In Large Gaps And Openings
 ▪   Prevents Drafts And Offers Sound Surface For Caulking Projects
 ▪   Provides A Sound Surface For Caulking Projects
 ▪   Mfg #WS31522