As a general guide, most tile roofs under the North Shore’s tree canopy benefit from a professional soft-wash clean every 2–3 years, and more often if the roof is heavily shaded or sits under gum trees.
Why North Shore roofs get dirty faster
Suburbs like Wahroonga, Turramurra, Pymble and Hornsby sit under some of Sydney’s tallest tree canopy. The shade keeps tiles damp for longer, and leaf litter holds moisture against the surface. Those are ideal conditions for moss, lichen and black algae streaks.
Left alone, moss and lichen hold water against tiles and can work into joints and pointing, while debris builds up in valleys and gutters.
Signs your roof is due for a clean
- Green moss or yellow/grey lichen spots on tiles
- Black streaks running down the roof
- Tiles looking noticeably darker or patchy compared with the neighbours
- Gutters and valleys filling with organic debris
- Moss falling onto paths and driveways
How often: a simple rule of thumb
- Heavily shaded or under gum trees: every 1–2 years
- Partly shaded, some trees nearby: every 2–3 years
- Open, sunny position: every 3–5 years, or before selling or painting
Soft washing vs high-pressure cleaning
High pressure can blast moss off quickly, but it can also strip the surface of older concrete tiles, dislodge pointing and push water under tiles. A soft wash uses low pressure with a cleaning solution that kills the growth at the root, so it rinses away and is slower to come back.
Every roof is different, so we inspect it first and recommend the gentlest method that will do the job.
Common questions
Is it safe to clean a tile roof myself?
Working at height is dangerous, and high-pressure cleaners can damage tiles. For most homeowners it is safer and more effective to have the roof inspected and soft washed by a professional.
Will cleaning stop moss coming back?
Cleaning removes the existing growth. Treatment and keeping overhanging branches trimmed both help slow regrowth, but shaded North Shore roofs will need periodic cleaning.
Need help with roof cleaning & restoration?
We service the Central Coast, Newcastle & Lake Macquarie and Sydney’s North Shore.