The phone does a particular thing in DFW when a front comes through in January. Nothing on Tuesday, and then Wednesday morning at 6am, when it is 19 degrees and everybody is trying to leave for work, we get a week’s worth of broken springs in about four hours.
People assume the cold broke them. It is a reasonable assumption and it is not quite right, and the difference matters because it changes what you can do about it.
What a spring is doing before it breaks
The torsion spring above your opening stores almost exactly the weight of the door. That is why a 250-pound door can be lifted with one hand when it is set up correctly, and why a broken spring turns the same door into something that will not move.
The spring is the only part of a garage door doing real mechanical work on every cycle, and it is rated in cycles rather than years. One cycle is one open and one close. A common residential spring is rated somewhere around 10,000.
Divide that by your household’s daily use and you have the honest life expectancy. Six opens a day is about four and a half years. Two a day is over thirteen. Same part.
How a spring actually fails
Not by getting weak. By fatigue.
Every cycle, the steel wire is twisted, loaded, and released. Each of those cycles does a microscopic amount of damage at the points of highest stress. Cracks initiate at defects: a nick in the coating, a corrosion pit, an inclusion in the wire. Then they grow, a tiny amount per cycle, invisibly, for years.
At some point one of those cracks reaches the size where the remaining metal cannot carry the load, and the spring separates in a fraction of a second with the bang that wakes the neighbourhood. There is no gradual phase, which is why the failure feels so arbitrary.
So the spring that broke on Wednesday was days from breaking anyway. The cold was the last straw, not the cause.
What the cold actually contributes
Three real effects, all of them small on their own and all pointing the same way.
Steel is slightly less tolerant when cold. Fracture toughness falls as temperature drops, which means a crack that would have held at 70 degrees can propagate at 19. It is not that the spring got weaker; it is that it got less forgiving of the crack already in it.
Everything else got stiffer. Lubricant in the roller bearings and hinges thickens in cold. Weather seals harden and grip the floor. The door is genuinely harder to move on a cold morning, which means slightly more load through the spring on that cycle.
Thermal contraction. Steel shrinks as it cools, which changes the fit between the parts of the door and can add a little binding.
Add those to a spring that has used up its fatigue life and Wednesday morning is when it happens. Which is also why the second-coldest morning in a fortnight produces far fewer calls than the first: the ones that were ready have already gone.
What you can see before it happens
Springs do give some warning, and it is not what people look for.
- The balance test. Pull the release with the door closed, lift it by hand to waist height, let go. It should stay put. A door that sinks has springs that have lost tension, and that is the single most reliable indicator there is.
- The opener working harder. Straining, slowing near the bottom, or occasionally reversing for no visible reason. That is the opener carrying weight the springs have stopped carrying.
- Visible gapping between coils along part of the spring’s length.
- Rust between the coils. Corrosion pitting is where fatigue cracks start, so a rusty spring has a shortened life regardless of its rating.
- The date and the arithmetic. If the house is eight years old and still on its original springs, that is not maintenance any more. That is borrowed time.
Why both springs get replaced
On a two-spring door the second one is the same age, from the same batch, and has done exactly the same number of cycles as the one that just went. It is not a fresh part. It is a part that is days or weeks behind its twin.
Replacing only the broken one is not thrift, it is a deposit on a second call-out, and the second call-out includes the labour again.
The money question
No prices. What sets the number is how many springs the door has, the wire specification for its weight, and the cycle rating you choose.
The one thing genuinely worth paying more for is the cycle rating. Doubling the rating does not double the price of the job, because most of the job is the labour of doing it safely, and it roughly doubles the interval before you do it again. On a household using the garage as its front door, that is not an upsell, it is the correct part for the duty.
What not to buy
- Do not buy one spring on a two-spring door. See above. It is the most common false economy in this trade.
- Do not buy a heavier spring than the door needs. An over-sprung door creeps upward on its own and fights the opener’s safety reversal. The right spring is the one matched to the weight of the door.
- Do not buy a new opener because the old one struggled before the spring went. That struggle was the spring losing tension. Get the balance right, live with it a fortnight, then judge the opener.
- Do not buy a new door. A snapped spring says nothing at all about the condition of the panels.
A safety note we will not soften
Torsion springs are the one part of a garage door that a homeowner should not touch. The stored energy is substantial and it is released through winding bars that have to be controlled at all times. Cables, rollers and seals are reasonable things to look at. The spring is not, and the injuries from getting it wrong are severe.
The short version
The cold did not break your spring. It picked the morning. The spring was finished, because springs are rated in cycles and your household had used them up.
And the repair is usually a pair of springs and an hour, which is a perfectly ordinary job and disappointing news for anybody hoping to sell a door off the back of a bang at six in the morning.
Garage Doors Pro Service · (469) 693-9000 · garagedoorsproservice.com
Serving Dallas, Plano, Frisco, McKinney and the DFW metro.
