Why Toowoomba roofs go green
The wetter eastern suburbs
Along the Great Dividing Range on the city's eastern edge, rainfall nudges 1,000 mm a year, well above the airport's average. More rain, plus shade from established trees, means more growth on the roof.
Fog that lingers
Toowoomba sees fog more often than many Queensland towns. A roof that stays damp into the late morning, especially the shaded slope, gives moss and lichen what they need.
Cool, slow-drying winters
Winter maximums average about 17 °C, with frost on some nights. Roofs dry slowly in that weather, and a slippery, mossy roof on a cold morning is no place for anyone without proper fall protection.
Terracotta, concrete and iron
Monier says moss and lichen favour terracotta, especially unglazed, over concrete, though the growth sits on the surface and doesn't weaken the tile. Steel roofs mostly stay clean in the rain, but BlueScope says never to use abrasive or solvent cleaners on painted steel.
Old fibre cement roof? Don't clean it
If your roof is fibre cement on a house built before 1990, treat it as asbestos until a lab test says otherwise. Queensland can fine a homeowner up to $10,000 for pressure cleaning asbestos cement, and they pay for the clean-up as well. The state's advice is a fungicide and sealant instead. Read is my roof asbestos? before anyone quotes.
Which cleaning method suits your roof?
| High-pressure clean | Low-pressure wash and treatment | |
|---|---|---|
| Concrete tiles | Monier advises against pressure washers on tiles | Gentler on tiles and pointing |
| Terracotta | Risky, especially on old or brittle tiles | Usually the safer choice |
| Colorbond or iron | Rarely needed | Mild detergent and a soft broom, as BlueScope suggests before painting |
| Fibre cement, possibly asbestos | Illegal in Queensland | Fungicide and sealant only |
Questions for a Toowoomba roof cleaner
- What is my roof made of, and could any of it be asbestos cement?
- Will you use high pressure or a soft wash on my tiles, and why?
- What do you treat moss and lichen with?
- If I collect rainwater, how will you keep runoff out of the tank?
- How will you protect the ridge pointing and any cracked tiles?
- Do you clear the gutters and downpipes once the roof is done?
Our advice on cleaning
Clean only when there's a reason: a repaint coming up, moss holding water against the roof, or gutters clogging with growth. On terracotta, a bit of surface moss alone isn't reason enough. On anything that might be asbestos, we'd skip cleaning entirely and talk to a roofer about sealing or replacing it. The national roof cleaning page explains methods, and our Toowoomba page covers local weather.
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.