The soft backer rod can be defined as a cylindrical type of rod that can be used to fill gaps between building materials. It is mostly used in internal environments where the moisture content is generally low. This is because it lacks water proofing and air resistant properties. However, the builder can use an appropriate type of sealant in order to ensure that the joint formed is less vulnerable to water, air and other fluids. Just as the name suggests, soft rods are easy to bend and compress. This makes them easier to install into cracks and joints that have a rugged shape.
The cylindrical shape of the soft backer rod plays a very vital role in sealing of joints. First of all, it prevents the sealant from penetrating past the recommended level. It only allows for the sealant to spread into the sides of the joint but not past the recommended depth. This means that the sealant is able to bond firmly with the building materials in order to form a stable joint. In addition to this, soft rods are do not bond with the sealant during formation of the joint. This feature makes the joint more flexible hence appropriate for movable and expandable building materials.
The soft backer rod is also known for its non-gassing nature. This simply means that it can work perfectly even if it is punctured during installation. This feature prevents bubbling of the sealant as seen in the closed cell backer rods. All the mentioned features make this type of backer rod easy to install and less expensive. One does not require sophisticated tools to install soft rods since they are flexible and pliable. The non-gassing nature also means that a variety of tools can be used since puncturing does not have any effect on the final joint that is formed.