Closed Cell Backer Rod available in multiple diameters and lengths Meets ASTM C1330, ASTM D5249 For Use with Cold Applied Sealants Closed Cell Polyethylene Foam Nonimpregnated, nonstaining, and nonbleeding Inert and does not adhere to sealants Meets all requirements of the 1990 Clean Air Act Is a "Domestic End Product" as defined by the Buy American Act , Title 41 USC 10 Closed cell backer rods are designed to limit the depth of sealants, help the sealant assume an hourglass shape (which prolongs sealant life), and serve as a bond breaker to prevent bottom-side adhesion. Backer rods do not stain sealants, and are chemically inert. They are non-gassing, non-exuding, and virtually dust-free. Due to physical and chemical inert nature, backer rod is compatible with virtually all known cold sealants, including self-leveling sealants - butyl, polysulfide, acrylic polyurethane, silicone, and most other cold-applied sealants Diameter of Rod: 3/8" Feet per Roll: 50 ft Joint Preparation and Installation: Clean all joints. Remove any concrete form-release agents, curing compound residue, laitance, and any other foreign materials. To ensure good bond, joints must be clean and dry when the new sealant is installed. Air compressors must be equipped with traps for oil and moisture removal. Install backer rod at depth recommended by sealant manufacturer - use a blunt tool. Commonly used in expansion/contraction joints such as: Curtain Wall Partitions Bridge and Highway Construction Parking Decks Pre-Cast Assemblies Glazing Applications Panel Systems