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The Different Types of Backer Rods for your Project

July 28, 2020

Backer rods and soft backer rods are a vital element of any sealant joints and are typically used to fill the gaps between two building materials. They have three primary functions; they serve as a bond breaker to avoid three-sided adhesion, they support tooling and they provide an hourglass shape that maximizes the bond area and movement while keeping the consistency of the depth of sealant.


Besides its main job as fillers for joints, they are also used in other applications such as tiling, flooring, wall panelling, and more. They come in standard diameter sizes ranging from ¼ to 4 inches thick. It helps to know the various kinds of  backer rods so you know which one is suitable for your project. 


Let's take a look at the different types:


Open-cell rod 

This is the easiest to install because of its pliability and can be easily compressed to fit different gap sizes and joints. It can also help facilitate the curing of a sealant of both sides. However, this backer rod is not advisable to use outdoors or in flat or horizontal joints as it has poor ability to repel water and is not a good insulator.


Closed-cell rod 

Backer rods made with closed-cell foam are best suited for outdoor and heavy-duty applications as they are firmer and denser. Soft backer rods can actually be used in place of closed-cell rods in most applications as they are suitable for specialty applications where free-flowing and self-levelling sealants are used. 


Hybrid type rod

This rod has an internal open cell structure and closed-cell exterior and can be installed in flat or horizontal works since they won’t wick water through. Just like a soft backer rod, it can also be used for irregular joint applications where standard backer rods are not suitable. 



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