How Often Should You Clean Your Roof in Brisbane?

Brisbane’s warm, humid, subtropical climate is paradise — for the lichen, moss and algae growing on your roof. If your roof has black streaks, green patches or crusty white spots, that’s biological growth, and it spreads. Here’s how often you should clean it and why getting it right matters.

The short answer

For most Brisbane homes: every 2–3 years, with a quick visual check once a year.

You may need it more often if:

• Your roof is shaded by trees (less sun = more moss)
• You’re near the bay or river (more humidity)
• You already have visible lichen or moss (it accelerates once established)

Why it matters (it’s not just looks)

• Lichen damages tiles. Its root-like structures bind to and break down the tile surface and grout over time.
• Moss holds moisture against the roof, which can lead to leaks and rot.
• It voids some warranties and drops kerb appeal fast if you’re selling.
• Blocked valleys & gutters — growth washes into gutters and clogs them (worth pairing with a gutter clean).

Catch it early and it’s a routine soft wash. Leave it for a decade and you’re looking at tile replacement.

Why NOT to pressure wash a roof

It’s tempting to blast it clean, but high pressure on roof tiles:

• Strips the protective glaze/coating, so it gets dirty faster next time
• Can crack or dislodge tiles
• Forces water under tiles and into the roof cavity

The correct method is soft washing — low pressure plus a biocidal treatment that kills the lichen and moss at the root. It keeps working after we leave, so the roof stays cleaner for longer. (More on the difference in pressure washing vs soft washing.)

Warning signs it’s time

• Black streaks running down the tiles
• Green or grey patches, especially on the shaded side
• Crusty white, grey or orange spots (that’s lichen)
• Moss visible in the tile joins or valleys

What a professional roof clean involves

A proper job isn’t just spraying. At Parer’s, roof cleaning includes safe roof access and harnessing, a biocidal soft-wash treatment for tile or Colorbond, careful rinsing, and gutter checks — all fully insured ($20M public liability, including height work).

If your roof is looking green or streaky, get a free quote — we can usually quote from a few photos, same day.