We get called about faded Colorbond roofs all the time around Nowra. The owner stands in the driveway looking up at a roof that used to be a crisp Monument or Surfmist and is now a chalky, patchy grey, and asks whether it can just be painted. The short answer on painting a Colorbond roof is yes, most of the time. The longer answer depends on what is going on under that faded colour.
You can paint Colorbond, just not straight over the top
Colorbond steel leaves the factory with a baked-on paint finish. That finish is tough, which is the whole point. It also means fresh paint has very little to grip unless the surface is prepared properly. Roll paint onto a dirty, chalky sheet and it can look great for a season before it starts lifting in flakes.
That chalky film is the old finish breaking down in the sun. Run a finger across a tired roof and it comes away coloured. If that powder is still there when the new coating goes on, the new coating is stuck to dust, not steel.
Paint only works if the steel underneath is sound
Paint is a protective skin. It does not put strength back into metal that has rusted away. Before we price any metal roof repaint, we walk the roof and sort what we find into three groups:
- Fading and chalking only. The ideal candidate: clean, prime, coat.
- Surface rust in spots. Usually fine, once the rust is treated back to clean metal.
- Rust holes, thinned laps, or rot along the gutter line. Those sheets get replaced first. Paint over them and you are paying to hide the problem for a while.
The places we check hardest are the ones that stay damp. That means the bottom edge of each sheet where it runs into the gutter, the overlaps between sheets, around the roof screws, and anywhere leaves pile up behind a flue or skylight. Rust nearly always starts in those spots rather than out in the open middle of a sheet.
If only a handful of sheets are past saving, swapping those through our metal roof repair work and then painting the lot is often the sensible middle path. If rust has gone right through the roof, it is a different conversation, and our post on whether to restore or replace an ageing roof walks through how we weigh that up.
Salt air near the coast changes the maths
Metal roofs in Culburra Beach and Shoalhaven Heads age differently to the same roof in West Nowra or Cambewarra Village. Salt carried in on the sea breeze settles on the roof and sits in the spots the rain never rinses: under the eaves overhang, along the sheet laps and on the underside of the ridge capping. Those sheltered spots often corrode first. This one surprises people, because they expect the exposed top of the roof to cop the worst of it.
For a coastal home, preparation counts double. Every trace of salt has to come off before primer goes on, and any patch that has started to bubble needs proper rust treatment, not a quick going over with a wire brush. Skip that and the corrosion keeps working away under the new paint.
A proper repaint is mostly preparation
The painting itself is the quick part. Here is how the work runs on a typical Colorbond roof.
Inspection and repairs come first
We check every sheet, screw, flashing and ridge cap. Rusted screws get swapped for new ones, loose flashings are refixed and any sheets beyond saving are replaced. Doing these repairs after painting would mean cutting through a brand new coating.
A high pressure clean
The roof is washed to strip off dirt, moss, lichen, salt and that chalky oxidised layer. On an older roof, the clean alone shifts the colour noticeably. That tells you how much was sitting on top.
Rust treatment on any bad patches
Rusted areas are taken back to clean metal and treated so the rust stops spreading under the new finish.
Primer made for prepainted metal
This is the layer that lets the top coats actually bond to the old factory finish. Skipping it, or using the wrong one, is the most common reason we see a painted Colorbond roof peeling.
Top coats of roof membrane
The finish coats are a roof membrane coating made for metal, usually sprayed so the film builds evenly into the corrugations. These coatings are made to flex as the steel heats up and cools down, which ordinary house paint is not.
All of this needs a dry roof and a dry forecast. On the South Coast in a wet spell, the schedule bends around the rain. We would rather wait a few days than coat a damp roof. If you want to see what is included on our jobs, the page on our roof painting service in Nowra sets it out.
A repaint is your one chance to change the colour
Repainting is the only time you can change the colour of a metal roof without replacing it, and plenty of owners go lighter. A pale roof reflects more of the summer sun, so the roof space underneath runs cooler than it would under a dark one.
The catch is everything else attached to the roof. Gutters, fascias, flashings and downpipes were all matched to the old colour. Take a roof from dark to light and you will want to decide whether those get painted too, otherwise the house can end up looking patched together. It is worth settling before the job starts rather than halfway through.
Sometimes painting is the wrong call
How we work is simple: look at the roof properly, explain what we found in plain English, price the job in writing, and tell you when the cheaper option is the right one. Now and then the honest answer is that painting is not the right option at all.
Painting is the wrong call when rust has gone through large areas of the roof, or when the roof leaks at the laps because the steel there has thinned out. It can also be wrong for a younger roof where the factory finish is simply dirty rather than worn. That last one is more common than you would think. A good clean can bring a grubby roof back, and a coating put on too early is money spent on something you did not need. If your roof is young enough to still be under the manufacturer’s warranty, check those terms before anyone puts a coating on it.
Not sure whether your roof needs paint, a few new sheets or more than that? Ryan Bruce leads our team, with more than 10 years of roofing experience behind the work, and we are fully licensed and insured. Call (02) 4409 2597 and we will come and look, explain what we find, and give you a free written quote. You can also read more about how we repaint metal and tile roofs before you call.
Common questions about painting Colorbond roofs
Is it cheaper to paint or replace a metal roof?
If the steel is sound, painting usually costs less because you keep the existing sheets and fixings. The sums change once a lot of sheets need replacing, since you end up paying for new steel as well as a full paint job. A walk over the roof tells you quickly which side of that line you are on.
How much does it cost to paint a Colorbond roof?
It depends on the size and pitch of the roof, how easy it is to get onto, and how much repair work is needed before any paint goes on. Rust treatment and sheet replacement are where prices move the most. We give a free written quote that spells out what is included and what is not, so you can compare it fairly.
Can I paint straight over Colorbond?
No. The factory finish is smooth and hard, and once it starts chalking it has a powdery layer on top. Without a thorough clean and a primer suited to prepainted steel, new paint has nothing solid to hold on to and tends to peel.
Can you use Dulux Weathershield on a Colorbond roof?
We would not put a general exterior wall paint on a roof. A roof takes far more sun and heat than a wall, and the steel moves as it warms and cools. Use a coating sold specifically for metal roofs, over the primer that goes with it, and check the label says it is made for roofs.
What is the best paint for a Colorbond roof?
A roof membrane coating designed for metal, applied as a full system with its matching primer. The system and the preparation matter more than the brand name on the tin. Good paint over a chalky, salty roof will still fail.
Can you paint a dark Colorbond roof a light colour?
Yes. A dark roof can be repainted in a lighter colour, and many owners do it to keep the house cooler. Plan for the gutters, fascias and flashings at the same time so everything still matches.
