What is a Extension Spring?
A spring that stretches and contracts along the horizontal tracks on either side of the garage door.
Extension springs are an older style of garage door spring that work by stretching (extending) when the door is closed and contracting when the door opens. They are mounted on either side of the door along the horizontal tracks. While extension springs are less expensive than torsion springs, they have several disadvantages: they wear unevenly, create more stress on the door hardware, and pose a greater safety risk if they break (they can fly across the garage). Most modern installations use torsion springs instead. If your home still has extension springs, safety cables should be installed through the center of each spring to contain them in case of breakage. Extension springs are still common in older Canadian homes built before the 1990s.