Why Hervey Bay roofs need cleaning
Humid afternoons
Mean afternoon humidity is 60%, and it rains on nearly ninety days in an average year. Roofs that rarely dry out fully, especially the shaded slopes, grow mould, moss and lichen.
Salt where rain doesn't reach
Roof sheets are normally rinsed by rain, but the sheltered bits aren't. BlueScope says unwashed areas such as eaves, garage door tops and gutter undersides should be washed every three months in coastal areas with salt spray.
Post-war homes and holiday flats
The bay's post-war coastal houses and its 1950s to 1970s motels and holiday flats were all built well before 1990. ASSEA says a home built or renovated before then probably has some asbestos, and fibre cement roofing is one place it turns up.
Fibre cement roofs: seal, don't blast
Treat any fibre cement roof on a pre-1990 house as asbestos until a lab test says otherwise. Queensland makes water blasting it illegal, with fines up to $10,000 plus clean-up costs, and suggests fungicide and sealant instead. ASSEA says pressure cleaning has spread fibres to neighbours' yards, footpaths and stormwater.
Doing it properly on a coastal roof
On tiles, Monier advises against pressure washers because they can crack tiles. A low-pressure wash with a treatment is gentler on older tiles and pointing.
On Colorbond or Zincalume, BlueScope says never to use abrasive or solvent cleaners such as turpentine or kerosene on painted steel, and not to wash with hard bore water. Sugar soap shouldn't go on bare Zincalume either.
If you collect rainwater, disconnect the tank inlet before the clean so dirty runoff and any treatment don't end up in the tank.
What you can do from the ground
You can
- Hose salt off eaves, garage door tops and gutter undersides every few months
- Disconnect the tank inlet before any roof clean
- Trim branches that shade the roof, if you can reach from the ground
- Note where growth is worst so the cleaner knows where to look
Leave to a roofer
- Cleaning the roof surface itself
- Treating mould and lichen
- Fixing tiles or pointing the clean uncovers
- Anything at all to do with a fibre cement roof
What to ask a Hervey Bay roof cleaner
- What is the roof made of, and have you checked for asbestos cement?
- What pressure will you use on my tiles, and how will you avoid cracking them?
- What will you treat the mould and lichen with, and is it safe near my garden?
- Will you wash the eaves, gutter undersides and other spots rain doesn't reach?
- Do you clear the gutters and downpipes afterwards?
What we'd tell a neighbour
Hose the sheltered, unwashed spots every few months and only pay for a full roof clean when there's a reason: a recoat coming up, growth holding water, or gutters clogging. If the roof might be asbestos cement, skip the clean altogether and ask a roofer about sealing it. The national roof cleaning page covers methods, and our Hervey Bay page the local picture.
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.