Backer Rod

What is a Backer Rod?

Definition: What Does the Term Backer Rod Mean?
A backer rod refers to any piece of material that is forced into a joint or a opening to form a stop for another material. For example, when caulking a joint, a piece of foam, or other synthetic material, is forced into the joint prior to the caulking application. The backer rod is intended to provide a stop to eliminate the insertion of an endless amount of caulk or sealant into a joint or opening. The backer rod is normally a resilient, pliable material that can be compressed into an opening and it springs back to push against the interior walls of the opening providing a firm seal and a stiff backup for the caulking or sealing operation.