The door faces the weather every day. In Metro Vancouver that means salt air, driven rain, and six months where the dew point never drops. Paint fails here faster than anywhere else in the country — not because the products are bad, but because the prep window is short and the substrate is usually damp.
Start by checking what you actually have. Steel doors with factory baked enamel need different treatment than raw cedar or a fiberglass skin over foam. Tap the panel with a knuckle. Steel rings. Wood thuds. Fiberglass sounds hollow and cold.
Why the coast eats paint
Moisture sits in the panel joints, the bottom seal groove, and the stiles. On steel it creeps under the factory coating at every scratch and hinge screw. On wood it drives the grain open, then freezes and expands. The result is the same: adhesion loss at the microscopic level. You cannot see it until a six-inch flake peels off in your hand.
Temperature swings matter too. A dark steel door in July hits 60 °C. The same door in January sits at 2 °C with condensation running the panels. The coating expands and contracts with the metal. If the paint film is brittle or too thick, it cracks. Once water gets in, the bond fails from the back side.
Steel doors — factory finish versus field coat
Most residential steel doors arrive with a polyester or silicone-modified polyester bake. It is thin, hard, and slick. Sanding it dull is not enough. You need a bonding primer designed for prefinished metal — waterborne acrylic urethane or a two-component epoxy primer if the door sees direct sun. Skip the all-in-one paint-and-primer. They do not build the film thickness you need at the edges and stiles.
Clean with TSP substitute, rinse until the water sheets, then wipe with a lint-free rag dampened with isopropyl alcohol. Let it flash thirty minutes. Prime only when the surface temp is between 10 °C and 25 °C and the dew point is at least 3 °C below surface temp. In this climate that often means waiting for a mid-morning window after the dew burns off but before the afternoon marine layer rolls in.
Two thin coats of 100 % acrylic topcoat. Satin hides roller stipple better than semi-gloss and still sheds water. Back-roll immediately after spraying or rolling to push film into the embossed grain. Watch the hinge edges — they take the most flex and get the thinnest film.
Wood doors — breathable is not optional
Cedar, hemlock, and Douglas fir all move. A film-forming oil paint traps vapor. The wood pushes, the paint lifts, water enters, rot starts. Use a penetrating oil-based primer — alkyd or linseed — that soaks into the cells and stays flexible. Topcoat with a high-quality acrylic latex formulated for exterior wood. It breathes enough to let vapor escape but blocks liquid water.
Strip loose paint to sound wood. A heat gun and carbide scraper work faster than chemical strippers on vertical panels and leave no residue. Sand 80 grit, vacuum, tack cloth. Prime all six sides of every panel if you can reach the back. End grain at the bottom rail drinks primer; hit it twice.
Two topcoats minimum. Three on the bottom rail and the exterior faces. Maintain a wet edge across the full panel height. Lap marks on a garage door are visible from the street at noon.
Fiberglass and composite skins
These doors have a gel coat or molded color. Light sanding with 180 grit, clean with acetone, then a bonding primer rated for fiberglass — usually a waterborne urethane. Topcoat with the same acrylic you would use on steel. Do not use oil-based products on fiberglass; they never fully cure on the plasticized surface.
The mistakes that cost a repaint in six months
Painting over chalk. Run a finger across the old finish. If pigment comes off, wash with TSP and rinse until the rag stays clean. Chalk kills adhesion.
Painting in the fog. Surface moisture is invisible. Wipe the panel with a dry black cloth. If it leaves a dark streak, the door is wet. Wait.
Skipping the bottom rail. That rail sits in standing water every rain event. It needs primer, two topcoats, and a bead of paintable silicone where the weather seal meets the door.
Painting the weather seal. The vinyl or EPDM seal stays flexible. Paint cracks it in weeks. Tape it off or remove it.
Using interior paint. Seen it. Peels in sheets by October.
Rolling texture into the stiles. The stiles are flat. The panels are embossed. Roll the stiles smooth. Texture only the panels if you are matching the factory look.
Tools that make the difference
- 4-inch microfiber roller, ¼-inch nap for steel, ⅜-inch for wood
- Purdy Nylox brush for cutting edges and stiles
- Dew point calculator on your phone
- Painter’s pyramids to prop the door open on the horizontal tracks while the bottom rail cures
When to call it
If the steel has rust perforations, the wood has soft spots you can push a screwdriver through, or the fiberglass is delaminating at the rails, paint is a bandage. The door needs replacement. We see it every spring — a fresh coat on a door that fails structurally six months later. The money goes in the bin.
A proper prep and paint job on a standard double door takes two days with dry weather: clean and prime day one, two topcoats day two. In this climate you watch the forecast like a hawk. Three dry days in a row is a luxury. Plan for it.
If the door operates rough, binds, or the springs are older than ten years, fix the mechanics first. Painting a door you have to replace the hardware on next month is wasted effort.
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Call 778-873-7282 — Metro Vancouver.