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Considering the Variety of Backer Rods Available

August 28, 2019

When it comes to sealant joints, backer rods are a pivotal component in your arsenal, especially when you are looking to plug gaps between two building materials.


There are a great many advantages you can look forward to when using a backer rod due to their main functions:


·        Three-sided adhesion (when adhesion of the sealant occurs on both sides and the bottom of a joint) is prevented when employing a backer rod. This is important as it promotes malleability within the sealant.

·        The use of tooling is aided because of the capacity for the sealant to be pushed to the bond line; assuring the flow of the sealant to maximise contact area to the substrate.

·        Encouraging the development of an hourglass shape – this allows for a more consistent depth for the sealant while also allowing for maximal bonding area.


While the benefits of backer rods are well regarded, it is important you become familiar with the type of backer rod being implemented for your sealant projects.


Three Types of Backer Rod

Although backer rods are commonly employed for their usage as a filler for joints, their applications extend beyond this and can be used for situations such as flooring, wall panelling, and tiling; with standard diameters ranging from ¼ to 4 inches thick.


There exists three types of backer rod, each lending themselves to specifically suited jobs. Tailoring the type of backer rod for your project can only be done effectively when you take a deeper dive into the characteristics surrounding each one:


1.   Open Cell Rod

These rods are known for their effortless installation due to how pliable they are, allowing them to be compressed during installation into a multitude of gap sizes. Additionally, their open celled structure expedites the curing of the sealant.


However, it is cautioned to avoid using an open celled backer rod for flat, horizontal, or outdoor joints as it does not act as an effective insulator or water repellent.


2.   Closed Cell Rod

In contrast to the open cell backer rod design, closed cell backer rods display properties that make them suited towards outdoor, and more industrial style environments due to their firmer and denser form – allowing for more insulative and hydrophobic tendencies.


Proper installation by an expert is recommended so that unaesthetic outgassing (trapped gas housed within a bubble) can be avoided.


3.   Hybrid Rod

This rod design makes use of the open cell design for its internal cell construction in combination with a closed cell design for its exterior. Unlike purely open celled rods, these rods can be implemented for flat or horizontal joints as water content does not pass through its internal structure.


As you can see, backer rods display a host of unique functionalities amongst the types available on the market. Because of this, we recommend you consult with a professional at Alcot Plastics to ensure you select the right backer rod for your unique project. With almost 40 years of experience, you can be sure your sealant applications will be met with the backer rod products we have available.