Mould on the eaves: the strip rain never washes
Mould grows on eaves because they are the one strip of your exterior rain never washes — sheltered, shaded and still, they become a spore bed. The fix is a gentle low-pressure wash, which is what James Hardie's maintenance bulletin specifies for fibre-cement. Schmick cleans eaves as part of the house soft wash, from $300 — most single-storey washes run $420 to $960.
The strip rain never touches
Walk to the edge of your lawn and look up. The underside of your roofline — the eaves — is often the dirtiest surface on the house, and the one nobody checks. Walls get rinsed every time it rains. Eaves never do. They are built to shed water outward, which means the lining underneath is permanently sheltered from the one thing that keeps every other surface on your house roughly clean.
Sheltered also means shaded. No rain, little direct sun, still air, and — on the harbour side of Sydney — humidity for most of the year. Mould and mildew settle on the eaves lining, feed on the dust film that accumulates there, and spread as grey-black speckling along the boards. South-facing runs go first. By the time you notice it from the driveway, it has been there a while.
It is growth, not grime
The dark speckle on eaves is rarely dirt. Dirt washes off. This is organic growth living on the surface, and it behaves like something alive. Wipe a patch and it smears; leave it and it spreads along the board joins and around the downlights, following the damp. It also travels — eaves sit directly above your walls and windows, and spores do not respect boundaries.
Gutters make it worse. An overflowing gutter runs water down the fascia and across the eaves lining, leaving tide marks and a permanently damp edge that growth colonises fast. If your eaves are streaked as well as speckled, the gutter above them is usually part of the story — worth sorting before the wash, not after, or the streaks come straight back with the next storm.
Gentle washing — the manufacturer's own rule
Most Sydney eaves are lined with fibre-cement sheet, and its maker has already ruled on how to clean it. James Hardie's maintenance bulletin specifies gentle washing for fibre-cement cladding, not high pressure. That is a directive, not a preference. A pressure lance aimed up at an eave drives water into the sheet joins and the roof cavity, flakes the paint, and can leave the lining wetter inside than any weather ever makes it.
Soft washing does what the bulletin asks. Low pressure, the right solution, dwell time to treat the growth at the root rather than shave the top off it, then a controlled rinse. Because the organism is killed instead of relocated, the eaves stay clean longer than a blast-and-run ever manages — and the paint and sheet underneath keep their finish.
What a wash will and will not fix
Honesty first: a soft wash removes the growth and the staining sitting on the surface. It will not fix everything. Paint that has already broken down under years of mould will look better, not new. A long-standing gutter overflow can leave a ghost of a tide mark where water has worked into the coating. And if the lining itself is sagging or water-damaged, that is a repair, not a clean.
We will tell you which is which on the day, and photograph the result either way. What the wash reliably delivers is a bright, even roofline all the way around the house — and because the growth is treated rather than smeared about, it does not shadow straight back the way a quick wipe-down would.
One pass, not a separate job
Here is the practical part: eaves cleaning is not a separate service, and you should be suspicious of anyone selling it as one. At Schmick it is done inside the house soft wash — walls, eaves, fascia and trims in the same pass, with the same low-pressure method the cladding manufacturer specifies. One crew, one visit, one finish line right around the house.
A house soft wash starts at $300, and most single-storey washes land between $420 and $960 depending on wall area; two storeys adds about 40 per cent. You do not need someone to come and stare at your eaves to learn your number. The instant quote returns a firm, bookable price in about 60 seconds, and it holds unless the place is materially different.