Why garage door springs break
Springs fail from fatigue, not from abuse. Every open-and-close is one cycle, and a standard spring is rated at roughly 10,000 of them. A household opening the door four times a day reaches that in about seven years; one opening it ten times a day gets there in under three.
Three things accelerate it. Rust, which pits the steel and creates a stress point — the reason a light oiling once a year genuinely extends spring life. Incorrect sizing, where a spring that was never right for the door weight has been fighting from day one. And imbalance, where a worn partner spring, dragging rollers or a bent track make the surviving spring work harder than it was rated to.
Signs a spring is about to go
The failure is instant but the warning is not. A spring on its way out shows up first in how the door behaves, and it is worth acting at that stage rather than the next one.
- The door feels heavier by hand than it used to, or will not stay at waist height
- It opens more slowly, or the motor sounds like it is straining on the way up
- You can see a gap in the coil, or the spring has separated into two visible sections
- The coils look rusty, stretched, or unevenly spaced along the length
- The door judders or jerks upwards instead of moving in one smooth run
- It slams the last stretch on the way down instead of settling
What happens when a spring breaks
The door becomes its raw weight — commonly 80 to 140kg on a double sectional. An automated opener will strain, trip its overload and stop, or lift the door 100mm and give up. If the opener is strong enough to keep trying, it damages itself, the trolley, and eventually the top section of the door.
Manually, the door is now genuinely dangerous. A door part-way open on a broken spring is held by nothing but friction and the second spring, if there is one. It can come down fast and it does not stop for whatever is underneath it.
The right response is to stop. Leave the door closed if it is closed. If it is open, do not walk under it, do not put a car under it, and call for an emergency garage door call-out.