Why garage door springs break, and what to do the moment one does

A garage door spring is rated by how many times it can be wound and unwound before the metal fatigues. One cycle is one open and one close. A standard spring is rated at roughly 10,000 cycles.

For an average household opening the door twice a day, that is somewhere around ten to fourteen years. But if your garage is the door everyone actually uses — school run, work, groceries, bins — you can easily hit six or eight cycles a day, and the same spring is done in four or five years. Nothing has gone wrong; it has simply reached the end of what it was built for.

What shortens it further

• Rust, which eats the coil and is common in unheated Chicago garages
• An unbalanced door forcing the spring to work past its design load
• A heavier replacement door fitted without re-rating the spring
• Cheap springs on a builder-grade installation

People often assume the opener has died, because the opener is the part that visibly stops working. There is a quick way to tell them apart.

Pull the emergency release cord to disconnect the opener, then try lifting the door by hand. A door with healthy springs is counterbalanced and should feel like lifting ten or fifteen pounds — most adults can raise it one-handed. If it feels like lifting the entire door, which on a double door is 150 pounds or more, the spring is gone.

Other signs it's a spring

• A visible gap in the coil of the torsion spring above the door
• The opener strains, lifts the door a few inches, then reverses
• The door slams down rather than lowering under control
• The door opens crooked, one side lagging behind the other

This is the part worth taking seriously. The springs, not the opener, carry the weight of the door. The opener is only designed to guide a counterbalanced door along its tracks.

Run the opener with a broken spring and you are asking a motor rated for a few pounds of effort to lift the full weight of the door. Best case you burn out the drive gear and turn a spring repair into a spring plus opener repair. Worst case a cable snaps under the load or the door comes down.

If the door is stuck open and you need to secure the garage, that is a reasonable time to call for emergency service rather than improvise.

On a door with two springs, we replace both even when only one has broken. This occasionally reads as an upsell, so here is the actual reasoning.

The pair was installed at the same time and has done exactly the same number of cycles. If one has reached the end of its fatigue life, the other is within weeks or months of the same point. Replacing one leaves you with a door that is now unbalanced — the new spring is stronger than the old one — and a near-certain second call-out.

Where a door only has a single spring, we replace the single spring. We are not going to invent a second one.

We are generally happy to tell people when something is worth doing themselves. Photo-eye sensors, lubrication, tightening a loose bracket — go ahead. Spring replacement is the exception.

A wound torsion spring stores a serious amount of energy. Releasing it requires proper winding bars and correct torque, and the failure mode when it goes wrong is the bar or the spring travelling at speed through whatever is in front of it. Screwdrivers and rebar are not winding bars. This is the repair that puts people in hospital, and it is not worth the saving.