What Sydney's weather does to roof paint
Western suburbs bake
Penrith set a record of 48.9 °C on 4 January 2020, and Observatory Hill's record is 45.8 °C from 18 January 2013. Strong sun is what fades a coating: UV breaks down the acrylic binder in the paint, which Dulux calls chalking. Out west, the coating's warranty terms matter as much as the colour.
Colour is a heat decision
BlueScope says light roofs can be up to 35 °C cooler on the surface than dark ones in hot sun. For BASIX, NSW calls a roof colour light below a solar absorptance of 0.475 and dark above 0.7. On a hot western block, a pale colour can make a real difference upstairs. Our heat-reflective coatings page goes further.
Salt near the beaches needs a better primer
For repainting coated steel, BlueScope generally recommends water-based acrylic, with a more corrosion-resistant system such as a zinc-rich primer in salty marine locations. If you're near Manly, Bondi or Botany Bay, ask what primer is going on, not just the topcoat colour.
Pick your dry spell
On 1991 to 2020 averages at Observatory Hill, September (63.4 mm) and October (67.7 mm) are the driest months, while June is the wettest. Southerly busters begin in October and can bring a sudden wind change, so a good painter watches the forecast closely.
Heritage terracotta is described by its glaze
Haberfield's heritage controls describe acceptable roof tiles as unglazed terracotta matching the originals in colour and glaze, among other things. Painting tiles there changes exactly what council is protecting, so ask Inner West Council first.
Which Sydney roofs are worth painting
Concrete tiles: yes, if you want the look back. Monier says a repaint refreshes them but needs redoing every five years or so to keep that look, and adds nothing to waterproofing.
Metal: sometimes. BlueScope says overpainting COLORBOND or ZINCALUME voids its warranty, and minor scratches under 2 mm wide that can't be seen from the ground are best left alone. An old, weathered metal roof with no warranty left is a fair candidate for a coat after rust treatment.
Terracotta: rarely. Monier doesn't recommend it, and once unglazed terracotta is painted it needs recoating from then on.
If you collect drinking water from the roof, check the paint system suits it first, since BlueScope says not all do.
Asbestos roofs aren't pressure cleaned, ever
Painting usually starts with a clean. If the roof could be asbestos cement, which the NSW EPA says is likely on homes built before 1990, high pressure water is illegal on it in every state. Get it tested first, and read painting an asbestos roof before anyone quotes.
What to ask a Sydney roof painter
- Which coating system are you using, how many coats, and what does its warranty cover?
- What primer goes on first, given how close I am to the coast?
- What's the solar absorptance of the colour I've picked, and is it light, medium or dark under BASIX?
- Will broken tiles and ridge mortar be fixed before painting?
- How will you clean the roof, and have you checked it isn't asbestos?
Our view
We'd only paint a concrete tile roof if the faded look bothers us, and only after repairs. On terracotta, we'd put the money into ridges and broken tiles instead. On metal, we'd check the warranty before anything goes on. Whatever the roof, we'd choose a light colour out west and book the job for a dry spring week. The national roof painting page explains the process, and the Sydney hub covers local conditions.
Want a roofer to take a look?
Tell us the job and your postcode. We match it with a Find My Roofer certified roofer who specialises in that kind of work, and they call you to quote. Your number goes to them alone.