Backer Rods

Widest range of backer rod products for use in cold- and hot-pour sealant applications

Backer rods are round, flexible lengths of foam that are used as a “backing” in joints or cracks to help control the amount of sealant used or the depth of the sealant in the gap. Some applications require closed cell back-up material that won’t absorb moisture, others seal best with open cell foam that is highly compressible and will fill irregular joints more evenly. No matter your application, Armacell offers the most extensive collection of backup materials and the largest range of sizes on the market. Combined with outstanding service, prompt delivery and competitive pricing, Armacell is the only one-stop source for all your backer rod requirements. Armacell’s backer rods are sold through Sealant and Accessories distributors in the US and Canada.

Four Backer Rod Families to Choose From

FillPro Standard Backer Rod is an extruded round, closed cell, low density polyethylene (PE) foam material with a skin-like outer texture. Standard backer rod is non-absorbent, flexible and compressible allowing for easy installation in joints as a backup material for sealants. It’s available in spools in ¼” to 1 ¼” diameters or 6’ lengths for sizes over 1 ½” diameter. Standard backer rod is recommended for glazing installations, window and door applications, expansion joints, log construction, pavement joints or repairs and precast concrete joints and copings. It’s compatible with most cold-applied sealants.

FillPro Hot Rod XL Backer Rod is an extruded round, closed cell, low-density PE foam material which has been specially crosslinked to withstand temperatures in excess of 400°F (204°C). It is chemically inert and will resist oil, gasoline and most other solvents. The material will not stain, absorb moisture, nor adhere to sealant materials and is non-exuding. It’s available in spools in 3/8” to 1 ¼” diameters or 6’ lengths for sizes over 1 ½” diameter. Hot Rod XL backer Rod is a backup material for most hot-pour sealants used to fill contraction and expansion joints of concrete highways, runways, driveways, and parking lots. It’s compatible with most rubber-asphalt and coal tar-rubber polymer thermoplastic compounds.

FillPro Soft Type Backer Rod is a pliable bi-cellular PE foam material used for filling irregular joints. It is chemically inert and will resist oil, gasoline and most other solvents. The material will not stain, or adhere to sealant materials and is non-exuding. It’s available in spools in 3/8” to 1 1/8” diameters or 6’ lengths for sizes over 1 ½” up to 4”diameter. Its unique construction is highly compressible, but has a closed cell outer skin to resist moisture. Particularly suited for specialty applications where standard backer rods are not appropriate, FillPro Soft Type is ideal in irregular joint applications particularly where self-leveling, flowable sealants are employed. Also recommended with sealants where bubbling concerns are critical. An excellent all-purpose backer rod, it may be used in place of most standard backer rod applications.

FillPro Open Cell Backer Rod is a pliable open cell polyurethane (PU) foam material used for filling irregular joints. It is chemically inert and will resist oil, gasoline and most other solvents. The material will not stain, or adversely adhere to sealant or caulking materials. It’s available only in spool-less bags in 3/8” to 2” diameter. Open cell backer rod is commonly used in expansion and contraction joints, window glazing, curtain wall construction partitions, precast concrete assemblies and copings, parking decks and bridge construction. It’s compatible with virtually all known hot-pour and cold-applied sealant including silicone and rubber asphalt.

FillPro® Flat Backer Rod (FBR) is an expansion joint filler that will allow concrete movement, keep out debris and is moisture resistant. FillPro FBR is made of closed-cell, polyethylene which is completely waterproof, so it won’t swell or absorb water that might freeze in the winter. It’s semi-rigid, so it’s stiff enough to slide into joints easily, but unlike bulky fiberboard, it will follow curves with ease. FillPro FBR is lightweight, sold in 50-foot rolls of 4” width and ½” thickness, and can be transferred easily to the jobsite. It can be used with cold-pour sealants or with none at all. For even more convenience, the filler strip is pre-slit with a ½” tear-off tab that can be left above the height of the wet concrete, then easily pulled away when dry to make a flush installation (or place slightly receded to leave room for sealant).