How long does exterior paint last in Queensland?

Short answer: it comes down to each wall

There's no honest single number for how long exterior paint lasts. Dulux and Taubmans, the two systems we use as our default on Coast houses, both guarantee against the paint letting go of the wall. Neither promises how long the colour stays fresh. Dulux's trade advice puts it plainly: the Weathershield guarantee doesn't cover fading or chalking, because the local climate has a big say in how colour holds up.

That's why two walls on one house can wear at very different speeds. Dulux says fading happens faster on surfaces that get a lot of sun over a long time, and that lighter colours outlast darker ones in the same paint and conditions. A pale wall in the shade can still look sharp when a dark wall in full sun has gone flat and powdery.

Some colour change is expected. Dulux cites Australian Standard AS/NZS 3730.20, which sets "moderate" discolouration after 24 months of exposure testing as the expected level of performance.

The other half of the answer is prep. Both guarantees hang on it. Dulux only stands behind Weathershield where it was applied and maintained to the product instructions, on a suitable and sound surface. Taubmans backs All Weather when it goes on properly prepared surfaces. Paint over rotten timber or loose old paint and the guarantee won't help, since Dulux requires a suitable and sound surface and excludes substrate failure.

Sunshine Coast sun and salt wear paint faster

Start with the sun. According to ARPANSA, Australia's radiation safety agency, the country gets some of the highest levels of solar UV in the world. ARPANSA also says UV isn't tied to temperature, so a cool, clear winter day still hits your walls. Even in midwinter, typical peak UV in nearby Brisbane sits around 4.

Dulux's trade advice explains what that UV does. Darker colours soak up more heat and UV, which stresses the pigments and speeds up the breakdown. Hot walls also expand and contract more, which puts extra strain on the paint and on whatever's under it.

Then there's salt and damp. Dulux says salt plus moist air makes a corrosive mix, and paint under constant exposure shows wear like fading sooner than you'd expect. Salt drift carries well past the dunes, and canal-front render holds it against the wall because the water stays close. The Coast is wet, too. The Bureau of Meteorology's Sunshine Coast Airport station averages about 1,490 mm of rain a year over roughly 107 rain days, with average 9am humidity of 71%.

That's why we treat walls one at a time. A coast-facing wall usually carries a heavier system than a protected one, and coast-facing and canal-front walls usually get a sealer pass first. For more on choosing paint for this, read our guide to the best exterior paint for coastal homes.

What the paint makers guarantee, and what they leave out

Here's what Dulux and Taubmans put in writing for the two exterior paints we use most on the Coast. We're a Dulux Accredited Painter and Taubmans Endorsed, so these are the systems we know best. Everything in the table comes from the makers' own pages.

Read the table the right way. These guarantees are about paint coming away from the wall. Colour fade sits outside the Dulux promise, and Dulux's trade advice says chalking does too. If you want the colour to last, pick a lighter colour where you can and look after the wall it goes on.

Signs your house is due for a repaint

Walk around the house on a dry day and look at each wall on its own. Any one of these means that wall is getting close:

• Chalk on your hand. Rub the paint. Dulux says a little chalking is a normal way for paint to wear, but heavy chalking means the paint film is wearing away.
• Faded or patchy colour, usually worst on the sunniest walls. Dulux says fading can't be reversed once it starts, and it often goes patchy.
• Fine cracks. Dulux says cracking starts as hairline cracks and later turns into flaking.
• Peeling, flaking or blisters. The paint is letting go. Work out why before you repaint, with our guide to why exterior paint peels.
• Greyed timber on fascias, sills and weatherboards. Dulux's prep steps say to sand and remove greyed timber before painting.
• Render holding salt on coast-facing or canal-front walls.

Chalky north walls, soft fascias and salty render are what we check first on Coast houses. You don't always need to do the whole place at once. At the free site visit we'll tell you which walls are worth doing now and which ones can wait.

A wall in worse condition needs more prep, and that shows in the price. In our instant estimate, a basic rendered home has a guide range of $7,000-$14,000 and a weatherboard home $10,000-$25,000 (standard repaint, single storey, good condition, GST included). Eaves, fascias and gutters on their own are $1,500-$4,500. In the estimate, a house in average condition adds 15% and one in poor condition adds 25% at the low end and 40% at the high end, and two storeys add 20-40% for access. These are guide ranges, not quotes. The firm price comes after a free site visit. The full breakdown is in our exterior painting cost guide.

How to make an exterior paint job last longer

Both guarantees depend on the prep. On our exterior jobs, sanding, filling and sealing take most of the days. Topcoat is the short part. Here's what helps:

• Wash it regularly. Dulux's Weathershield page recommends washing every year in sheltered or inland areas, and every 6 months in coastal areas.
• Go lighter on the hot walls. Dulux says lighter colours soak up less heat and UV. Our exterior house colours guide has more on choosing.
• Test old paint before going over it. Dulux's tape test: cut an X through the paint, press tape firmly across it and pull it off fast. If paint comes away with the tape, the loose paint has to be stripped first.
• Get the chalk off. Brush and wash a chalky wall, then run your hand over it once it's dry. If chalk is still there, Dulux says to prime or seal before the topcoat.
• Paint in the right weather. Dulux warns that rain or overnight dew on drying paint can damage it, and that hot or windy days can make water-based paint dry too fast and crack. Our guide to the best time to paint a house exterior covers timing.
• Seal render on salty walls. That's the sealer pass coast-facing and canal-front walls get from us. There's more in our guide to painting rendered walls.
• Fix soft timber first. Dulux's guarantee needs a sound surface, and it excludes substrate failure.

Second-storey walls, roof edges and eaves above a ladder are a job for a painter with the right access gear. Wash and check what you can reach from the ground, and leave the high work to a pro.

We've painted Sunshine Coast houses since 1985 (QBCC licence 1281728). If you'd like someone to look over your walls, see our exterior house painting service or check the suburbs we cover.