Why did my garage door cable snap?

A garage door lift cable usually snaps because it wore out or was strained: fraying and rust where it meets the bottom bracket, friction on the drum, or a door that was out of balance or jumped its track. The cause is worth knowing, but finding it means working next to the springs, which is a job for a technician. Stay clear of the door until one arrives.

The usual reasons a cable fails

Wear at the ends. Each lift cable runs from a bracket at the bottom corner of the door up to the spring system. It flexes and winds every time the door moves, and it takes the full weight of that side. Frayed strands near the bottom bracket or at the drum are the classic sign of a cable that simply wore through.

Friction from dryness and rust. Clopay's annual maintenance list says to lubricate all moving parts of the door with light household oil, including the lift cables at the bottom bracket button.^[1] A cable that never gets this, and sits in a damp or salty garage, rusts and grinds on its fittings.

A bent track or a door that jumped. A door that has come off its track loads one cable harder than the other, and a cable can kink or snap in that moment. Clopay says: "Check for bent track. If bent, call an authorized professional dealer."^[1] It also warns: "If the garage door and/or any of the supporting track are damaged, operating the door could be hazardous."^[1] If your door has been crooked or noisy, read why a garage door comes off its track.

An unbalanced door. The spring system is meant to hold the door's weight so that it stays put partway up. LiftMaster's monthly checklist says to manually operate the door and, if it is unbalanced or binding, to call a trained door systems technician.^[2] The U.S. Consumer Product Safety Commission says the same: "If doors are not "balanced," or if they bind or stick, they should be serviced by a professional."^[3] An unbalanced door works the cables harder.

The spring system. The cables and springs carry the door together, so a technician will look at both rather than the cable alone.

What you can safely look at

You can learn a fair amount without touching anything. From the floor, look at where the cable ended up, whether the door hangs crooked, whether the cable is on the floor or still on the drum, and whether strands are frayed or rusty. Take photos from a distance and note when it happened and what you heard. A loud bang followed by a door that will not lift, or one side hanging lower, points to a cable or spring. That information helps the technician and your written quote.

Do not run the opener, do not try to lift the door by hand, and do not touch the cables, the bottom brackets or the springs. Clopay's manual states: "Springs, cables, and bottom fixtures are under strong spring tension. Do not attempt to loosen any fasteners on these components. You could suddenly release spring forces and risk severe injury."^[1]

Why the cause matters for the repair

Replacing the cable alone fixes the symptom, not the reason. If a bent track, a worn drum, a damaged bracket or unbalanced springs caused the break, a new cable can fail again. Clopay says repairs to torsion spring hardware, including springs, cables and bottom brackets, should be made by a qualified door technician or a mechanically experienced person with proper tools and instructions.^[1] Ask the technician to tell you what they found, to check both cables and both bottom brackets, and to test the balance when finished. The procedure is outlined in how snapped garage door cables are replaced.

Preventing the next one

Once the door is repaired, the habits that matter are small. Watch the door run once a month for jerks, tilting or noise, and call if it is unbalanced or binding. Ask the technician whether the annual service should include lubricating the lift cables at the bottom bracket button, which is on Clopay's annual maintenance list,^[1] rather than doing it yourself. Fix track and hinge problems early, and call at the first sign of a door that sticks, binds or hangs crooked.

When to call a licensed pro

Call as soon as you hear a bang from the garage, see a cable on the floor or slack on its drum, or notice the door hanging crooked or refusing to lift. Do not wait to see whether it still works. On licensing, DPOR's hiring guide says: "If the work you are considering is valued at $1,000 or more, a valid Virginia Contractor’s License is required" for the category in which the contractor works.^[4] Under Va. Code § 54.1-1100, Class C contractors work on single contracts over $1,000 but less than $30,000.^[5] Ask any company for its licence number and check the licence before you agree to the work.

For prices, see how much it costs to replace a snapped garage door cable in Virginia. For the spring side of the system, read the difference between torsion and extension garage door springs. More background is in the garage door repair answers, and you can browse garage door repair businesses on Loclis.

When you are ready, describe the job once and licensed local pros will quote it.