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The Importance of Soft Rods in Construction

July 20, 2017

In modern residential and building construction projects, sealing joints and crevices is a major point of concern. Canada, in particular, is known for its harsh weather conditions and sudden changes in temperature, which prompts the need for proper insulation against such fluctuations. Soft rods are a type of backer rod used by construction companies and builders across the country to ensure the right sealant depth is reached in joints within a building.

Within the industry, the application of sealant to joints is known as “caulking”. Caulk can be based on polyurethane, silicone, acrylic, and other materials. Soft rods are made of a foam roll that varies in thickness based on the application and is compatible with all components of the caulking sealant.

The Role Soft Rods Play in Sealant Application

A sealant is applied using a cartridge loaded into a caulking gun. The objective is to achieve an hourglass profile, pushed into the joint being sealed. Soft rods of the correct thickness allow this profile to be obtained easily while preventing the sealant from going too deep into the joint. If sealant enters too deep into the joint, it could cause issues due to a phenomenon known as 3-sided adhesion, in which the sealant adheres to a 3rd surface within the joint instead of the intended two.

Additionally, a soft rod in the right position forces any sealant that hasn’t adhered to the required surface outwards. This prevents sealant wastage and ensures that 100% of the applied caulk attaches itself to the surfaces. This pushing action comes about due to the pressure applied by the caulking gun’s nozzle, which pushes the sealant against the soft rod and causes any uncured sealant to move.

Soft rods are among the cheapest construction materials out there, but the role they play in the application of caulk to irregular joints is a critical one.