What the cold does to a garage door, and what to do about it

Normal January lows in this metro sit around 20 degrees, the airport averages over eighteen inches of snow a year, and the record is 23 below. All of that arrives at the garage door, and it arrives in four specific ways.

Row of suburban houses with two-car garage doors along a snow-covered Kansas street, bare trees and grey winter sky overhead

One: springs break in the cold

Steel loses flexibility as it cools and old lubricant thickens toward something like treacle. A spring already near the end of its cycle count — and a standard spring on a door opened five times a day is finished at around six years — fails on the first properly cold morning rather than on a mild one. This is why the week after a cold snap is the busiest week of our year, and why a spring assessment in October is worth more than one in January.

You will hear it: a single loud crack, and then the opener strains or lifts the door a few inches and stops. What to do about it is on its own page, but the short version is do not try to lift the door by hand and do not pull the release cord with the door part-way open.

Two: the door freezes to the slab

Meltwater runs off the car, under the bottom gasket, and refreezes overnight. By morning the door is bonded to the concrete. The opener then tries to lift a door that is glued down, which tears the gasket, bows the bottom section or strips a drive gear — turning a forty-dollar seal into a real repair.

How to free it without damage:

Stop pressing the remote. Holding it down is what causes the damage.
Pull the release cord and try to break the bond by hand first — often a firm, steady lift is enough.
If not, warm the seam. Warm (not boiling) water poured along the bottom edge, or a hair dryer or heat gun played gently along it. Avoid an open flame and avoid boiling water on very cold concrete.
Once it is up, prop it and clear the ice and standing water off the slab, or it will bond again tonight.
Then deal with the cause: a hardened gasket, a settled slab, or water running in off the drive. See weather seals.

Three: sensors fog and frost over

A warm car in a cold garage puts moisture into the air, and it condenses on the first cold surface it meets — including the photo-eye lenses a few inches off the floor. A film of moisture or a rime of frost passes less light, the opener reads an obstruction, and the door refuses to close. It then works perfectly at lunchtime, which is why people assume the opener is dying.

Wipe both lenses with a dry cloth. If it keeps happening, the eyes may be mounted lower than they need to be within their permitted range, and a small adjustment helps.

Four: everything gets heavier

Cold grease, stiff rollers, a seal dragging on an icy slab and a spring losing a little of its lift all add up. The opener compensates until it cannot, and the usual casualty is the drive gear. A door that has started groaning in December is telling you something, and it is cheaper to listen in December than to replace a gear in January.

Before the first freeze: six things

Lubricate rollers, hinges, bearings and the spring with a proper garage door lubricant — not a general penetrating spray, which washes grease out and attracts grit.
Check the bottom seal. Close the door, turn the lights off inside and look along the bottom. Daylight means a gap. Hard, unspringy rubber means it has stopped sealing.
Clear the slab where the door lands, and look at whether the drive sends meltwater toward the garage.
Test the balance. Release the opener, lift the door to waist height, let go. It should stay. Drifting or sinking means the springs want attention before the cold finds them.
Clean the sensors and check both indicator lights are steady.
Test the safety reverse with a flat piece of timber in the door's path. It must stop and reverse on contact.

The full version of that list, with the detail, is the maintenance checklist.

Common questions

Why do springs always break on the coldest day?

Because cold is the last straw rather than the cause. Steel stiffens, grease thickens, and a spring that was already at the end of its rated cycles gives out under the extra load. A spring with years left does not break because it is cold — which is why assessing them in autumn is genuinely useful.

My door is frozen to the floor. Can I just force it?

Please do not. Holding the remote down against a bonded door is how gaskets tear, bottom sections bow and drive gears strip. Release the opener, try breaking the bond by hand, then warm the seam with warm water or a hair dryer. Clear the ice afterwards or it will refreeze tonight.

Should I use WD-40 on my garage door?

No. Penetrating sprays displace grease rather than providing it, and they attract dust and grit that then act as an abrasive. Use a proper garage door lubricant — silicone or lithium-based — on rollers, hinges, bearings and the spring coils. The tracks themselves should be clean and dry, not lubricated.

Is it worth heating the garage?

For the door, not really — it is the moisture rather than the temperature that causes most of the trouble, and a heated garage with a wet floor still fogs sensors. Insulating the door and sealing the bottom properly does more for the rooms next to the garage than heating the space does.

When should I book a pre-winter service?

October, or early November at the latest. The point is to find a tired spring while you still have a choice about when to deal with it. Once the first hard freeze arrives, everyone who skipped it is ringing at once and the diary tightens considerably.