Torsion or extension springs?

Every sectional garage door is held up by springs, and there are two kinds. Look up at the top of your door with it closed.

Torsion springs

One or two thick springs on a steel shaft right above the door, with a cable drum at each end. As the door comes down, the cables wind the springs up; as it goes up, the springs unwind and lift it. They’re on most doors fitted in the last twenty years.

Extension springs

Long springs running along the horizontal tracks on each side, stretched when the door is down. They’re cheaper and common on older doors. Each should have a safety cable running through it, so a broken spring can’t fly across the garage.

Which is better

Torsion springs balance the door more evenly, last longer, and are safer when they break, because they stay on their shaft. When we replace extension springs we usually suggest changing to torsion, and on most doors it costs only a little more.