How to Paint a Garage Door: Colorbond, Roller Doors and What It Does to the Warranty

Question 01

Can you paint a garage door?

Yes. A steel garage door can be painted, and BlueScope, which makes Colorbond steel, says its prepainted steel can be successfully overpainted. The catch is durability and warranty. Colorbond's finish is baked on in a factory oven, a brushed or sprayed paint weathers differently, and overpainting voids any warranty BlueScope has issued.

Many steel garage doors are made from Colorbond steel. Steel-Line, for one, says its doors are manufactured using it. BlueScope's overpainting bulletin explains that Colorbond steel is coated on a continuous coil line, then baked in a high temperature oven. Paint you put on at home is an air drying paint, and BlueScope says the durability of the Colorbond finish is often not matched by air dried paints, including touch-up paint.

So painting is a looks decision, not a repair. It can freshen a faded door or change its colour. It won't fix a door that is rusting through, scraping its guides or running heavy. Sort those out first, then paint.

• Standard Colorbond colours: can be overpainted after the prep below.
• Matt Colorbond: BlueScope says there is no texture match, and the prep changes the surface, so try a test area first.
• Metallic Colorbond: BlueScope has no colour match, and its overpainting advice doesn't apply to Metallic finishes. Ask BlueScope before you start.

Question 02

Does painting a Colorbond garage door void the warranty?

It voids BlueScope's warranty on the steel. BlueScope's bulletin says overpainting will void any warranties issued by BlueScope. The door maker's own warranty is a separate document. Steel-Line's, for example, doesn't cover surface coatings applied by others at the customer's request, so read your door's paperwork before the paint goes on.

Timing matters too. Steel-Line warrants its door surface coatings for 1 year from installation. On an older door, Steel-Line's coating cover may have run out, but its 2 year cover on door components and the separate BlueScope warranty can still be running, so check both before you paint. On a door a few months old, wait or ask the maker first.

Salt air brings its own warranty conditions, separate from paint. The makers' salt clauses and washing rules are set out in salt air and garage door rust.

Question 03

Can you paint a roller door without the paint cracking?

You can paint a roller door, but expect the paint to wear faster than on a sectional door. Every time a roller door opens, its curtain coils up on itself, so the slats rub together. DASMA, the US door makers' association, says field painted curtains show wear marks sooner than factory roll coated or powder coated ones.

DASMA's technical sheet on rolling door paint wear says the wear may appear as horizontal lines, mars or abrasions on the faces of the slats. How much wear you get depends on the curtain's finish, the door size, the weather it sits in and how often it runs. A roller door that opens many times a day will show it sooner.

DASMA's advice is to ask the curtain's maker before putting any finish on it, so the new coating suits the original one. It also says professional application and enough air drying time are essential.

Question 04

How do you prep a Colorbond garage door for paint?

Wash it, scuff it and let it dry. BlueScope says to wash aged Colorbond with household detergent and water, lightly roughen it with kitchen scourer pads (never steel wool) so the paint has a key, then wash, rinse with fresh water and dry again. A door under a year old needs mechanical abrasion first.

1. 01Close the door, then disengage the opener, as B&D says to do before any cleaning or maintenance.
2. 02Wash the outside with household detergent and water, using a mop or a soft nylon bristle broom, as BlueScope's bulletin sets out. Rinse with fresh drinking-quality water and let it dry.
3. 03If the door has been painted before, do Dulux's tape test. Cut a small cross in the paint, press 10cm of tape firmly across it and pull it off quickly. If paint comes away, scrape off the loose and flaking paint before you go further.
4. 04Lightly roughen the whole face with kitchen scourer pads to take the gloss off. BlueScope says don't use steel wool, because it leaves small metallic particles that can damage and stain the steel. Go gently on bends and panel edges.
5. 05Wash it again with detergent and water, rinse with fresh water and let the door dry completely.
6. 06Mask the tracks or guides, the lock, the weather seals and any glazing before you open a tin.

BlueScope says Colorbond steel that has weathered for one to two years typically shows a slight loss of gloss, and that a uniformly weathered surface should give adequate adhesion after a wash. BlueScope's care bulletin also says never to use solvent or abrasive cleaners, such as paint thinners or turpentine, on its prepainted steel.

Question 05

What paint sticks to a metal garage door?

For Colorbond, BlueScope says the most suitable paint for overpainting is generally a water-based acrylic. In salty coastal air you may need a system with more corrosion resistance, such as a zinc-rich primer. BlueScope's advice is to ask a reputable paint supplier which system suits your door and your street.

• Stay with one brand. BlueScope recommends not mixing paints from different suppliers, for example a primer from one and a topcoat from another.
• Near the beach, ask about primer. Dulux's Weathershield Gloss product page says that for galvanised iron and ZINCALUME steel within 1km of the sea, apply one coat of its all metal primer first. For Colorbond, Dulux says preparation depends on the condition of the steel and asks you to contact it for advice.
• Follow the tin. BlueScope says to follow the paint maker's instructions, especially on how it's applied and how thick the coat is.
• Bare or rusty steel is a different job. For ZINCALUME and zinc-coated steel where rust shows, BlueScope says to remove it with a stiff nylon bristle brush, then thinly apply a zinc rich etch primer. Rust coming through on a working part is a repair first.

Question 06

How do you paint a garage door safely, step by step?

Pick a dry, mild day, switch the opener off, mask the parts that move, then paint from the top down. Dulux says the temperature must stay above 5°C while the paint goes on and dries, and that rain or overnight dew on wet paint can damage it. Keep paint off the tracks and locks.

1. 01Check the forecast. Dulux says not to paint on excessively cold or humid days or when rain is forecast, and on cold days to stop early enough for the paint to dry before evening.
2. 02In the heat of the day, work on the shady side, as Dulux suggests.
3. 03Disengage the opener and leave the door closed while you paint the outside face.
4. 04Apply thin, even coats with the brush, roller or spray the paint maker lists. For Dulux Weathershield Gloss that's a synthetic brush, a 4-6mm nap roller or a spray gun.
5. 05Wait the recoat time on the tin before the second coat. For Weathershield Gloss, Dulux gives 2 hours, based on 25 degrees and 50% humidity.
6. 06Leave the door shut until the last coat has fully dried, then remove the masking.

Question 07

Should you touch up scratches instead of repainting?

Usually not on Colorbond. BlueScope doesn't recommend touch-up paint for scratches, because air drying paint weathers differently and the patch can stand out over time. It says minor scratches under 2mm wide that you can't see from ground level should be left alone, since the metallic coating under the paint still protects the steel.

BlueScope also says it has no recommended way to remove touch-up paint once it's on. A dab of paint can end up looking worse than the scratch. If a door is badly marked all over, a full repaint looks more even than a patchwork of touch-ups.

A dent that has cracked the paint is a different problem, covered in dented garage door repair. Rust on the springs, cables or tracks is a repair, not a paint job: book garage door repairs. For rust on the door face, read salt air and garage door rust.

Deadlock doesn't paint garage doors. What Thom can do is make sure the door underneath is right before the painter arrives. Every garage door service covers five checks: spring tension and balance, roller and track lubrication, hardware tightening, cable and drum inspection, and an opener and safety-reverse test.