Armacell Launches New Flat Backer Rod

  • ArmaComp™ FillPro® Flat Backer Rod fills deep gaps of concrete expansion joints 
  • Complements FillPro family of back-up materials 
  • Ideal for use on curved concrete structures 

Chapel Hill, NC, 17 October 2022 – Armacell, a global leader in flexible foam for the equipment insulation market and a leading provider of engineered foams, announced today the addition of FillPro® Flat Backer Rod (FBR) to the family of ArmaComp™ backer rod products. Already offering the largest size range and widest choice of backup materials in North America with its four current round backer rod products, FillPro FBR solves the problem of filling deep gaps of expansion joints in concrete structures, where round rods are not suited.

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, the FillPro line now includes five product types available in dozens of sizes, all manufactured in Canada. 

  • FillPro Standard - Closed Cell PE 
  • FillPro Hot Rod XL - Cross Linked Closed Cell PE  
  • FillPro Soft Type - Bi-cellular PE 
  • FillPro Open Cell - Open Cell Polyurethane foam 
  • FillPro Flat Backer Rod (FBR) – Closed Cell PE  

FillPro FBR product is an expansion joint filler that will allow concrete movement, keep out debris and is moisture resistant. The smooth flat strips are made of closed-cell polyethylene which is completely waterproof, so it will not swell or absorb water that might freeze in the winter. It is 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 easily transported on the jobsite. It can be used with cold-pour sealants or with none at all. For added convenience, the FBR filler strip is pre-slit with a ½” tear-off tab that can be left above the height of the concrete, then easily pulled away to make a flush installation (or place slightly receded to leave room for sealant). 

It’s important to use the right product for filling expansion or isolation joints in concrete,” says Mike Swanson, GM –Component Foams for Armacell. “At Armacell we have backer rod products for most types of gap filling, now including our Flat Backer Rod that works for extra deep gaps or curved structures. We’re a one-stop shop for North America’s widest range of backup products on the market.”  

FillPro FBR product is sold through Sealant and Accessories distributors in the US and Canada. For more information visit:  

© Armacell, 2022. ArmaComp, FillPro, and Hot Rod XL are trademarks of the Armacell Group.  


As the inventors of flexible foam for equipment insulation and a leading provider of engineered foams, Armacell develops innovative and safe thermal, acoustic and mechanical solutions that create sustainable value for its customers. Armacell's products significantly contribute to global energy efficiency making a difference around the world every day. With more than 3,200 employees and 27 production plants in 19 countries, the company operates two main businesses, Advanced Insulation and Engineered Foams, and generated net sales of EUR 677 million and adjusted EBITDA of EUR 117 million in 2021. Armacell focuses on insulation materials for technical equipment, high-performance foams for high-tech and lightweight applications and next generation aerogel blanket technology. For more information, please visit: Armacell in North America has five plants in the United States and one in Canada, with its regional headquarters in Chapel Hill, North Carolina. 

For product information, please visit:   

Download press release here.


Tom Anen
+352 2484 9828 

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