Garage Doors in Thorton Woods, OntarioA new door,chosen with care.

A silicone-based or white lithium garage door lubricant, sold for the purpose. Penetrating oils and general sprays are thin, attract dust and are gone in weeks; heavy grease traps grit. For the rubber bottom seal and weatherstrip, use only a silicone spray, since petroleum products attack rubber and make it brittle. Nylon rollers with sealed bearings need no lubricant, while ones with an exposed bearing can need a touch where their own maker calls for it. A small amount on each point, worked in by moving the door, is enough.

A monthly look of your own at rollers, cables, hinges and the reversal test keeps small problems small, and a professional tune-up once a year covers the parts you cannot safely handle: spring tension, cable condition, track alignment and opener settings. A door that has come off its track once is worth this attention, because the event often reveals wear that has been building for a while.

Salt does its work in the bottom foot of each vertical track, where slush drips off the car and sits. Push slush clear of the door's inside edge rather than letting it pool, and on a mild day wipe or rinse the brackets and the lower channel. A little silicone spray on the bracket fasteners in autumn helps them shed water. Keeping the threshold free of ice also stops the door being pulled against a stuck bottom section.

It has to match the door, which may not be the same thing if the old cable was wrong. Length is set by the door height, the drum profile and the lift type; diameter and construction by the door's weight. A cable that is a little long overlaps on the drum and wears; one that is short leaves the door out of level. The technician measures the door and the drum rather than trusting the old cable.

Watch for a door that feels heavier by hand when the opener is released, an opener that strains or slows, a door that drops the last stretch rather than settling, or one that drifts down when stopped halfway. Visually, look for stretched gaps between coils, rust streaks or pitting on the steel, and any sag in the shaft. A balance check when you notice these lets you plan a replacement rather than react to one.