Garage door painting in Calgary — built for road salt and chinooks.

Nothing on a Calgary house cycles through weather the way a garage door does. It faces the street, so it catches full afternoon sun and everything the plough throws at it, and it is a thin metal panel with air on both sides — so it heats, cools and moves faster than a wall ever will.

A chinook can swing the temperature more than 30°C inside a day. The door expands, contracts, and any coating that has lost its grip lets go a little more each time. Meanwhile the bottom 30 centimetres are living in salt: Calgary road treatments use magnesium chloride, which stays active down to about -15°C and is more corrosive to steel than plain rock salt. That is why the rust almost always starts at the bottom panel and works upward, not the other way around.

Then there is the light. Calgary sits at roughly 1,100 m with about 333 sunny days a year, and UV at that elevation is unforgiving. South- and west-facing doors — most of Tuscany, Aspen Woods, Mahogany — chalk and fade visibly faster than a north-facing door on the same street.

People ask for garage door painting as if it is one service. It is not. The substrate decides the primer, the primer decides how long the finish lasts, and getting that one choice wrong is why so many repainted doors peel within two seasons.

Steel and aluminum doors — the majority in Calgary — carry a baked factory finish that ordinary house paint slides off. They need a light sand for mechanical grip and a direct-to-metal, rust-inhibiting bonding primer, then a sprayed exterior acrylic enamel. Sprayed, because a roller texture on a flat street-facing panel is visible from the sidewalk.

Wood doors move with the seasons, so the coating has to move with them. Edges and joints get sealed — all the way around, not just the face you can see — and the finish is a flexible exterior enamel rather than something brittle. Vinyl and composite skins need a bonding primer made for plastic, and there is a real limit on how dark you can go before heat becomes the problem.

A garage door is usually a half-day job, and most of that half day is preparation. The painting part is quick; the reason a repaint lasts is everything that happens before it.

The size of the door sets the base number, and the condition sets everything after it. A five-year-old steel door in Mahogany that just needs a wash, sand and two coats sits at the bottom of the range. A 1990s double in Ranchlands with rust through the bottom panel and a previous coat already lifting is mostly labour.

One more thing worth knowing before you pick a colour: going from a dark door to a light one usually needs an extra coat, and going very dark on a sun-facing door means more heat and more movement in the panel over its life.

A new garage door installed in Calgary generally starts around $1,500 and climbs past $5,000 for an insulated, windowed, carriage-style unit. A repaint is $350 to $900 and done in an afternoon, which makes it one of the cheapest changes you can make to the front of a house.

We will tell you when it is the wrong call. If a panel is rusted through, the door is delaminating, or the opener and springs are at the end of their life anyway, paint is money spent on top of a replacement you are going to make regardless. If the door works and only looks tired, repainting wins comfortably.

The practical window is May through September, when daytime temperatures hold above 5°C and there is enough dry time between the primer and the finish coats. Painting a door colder than that is the single most common DIY failure we get called to fix — the coating never properly forms a film, and it bubbles or peels the following spring.

Plan on keeping the door closed for four to six hours after the last coat so the edges and the seal do not bond to each other. Book in the shoulder season and you get the calendar; leave it to August and you are competing with every exterior job in the city.