Roof Cleaning Perth: How Often, Methods & Costs

Perth's roofs accumulate lichen, moss, algae, and dirt — particularly on the shaded south-facing sides. Regular cleaning extends roof life and maintains your home's appearance. Here's what to know.

Why Roof Cleaning Matters

Lichen and moss retain moisture against roof tiles, accelerating deterioration. Left untreated on terracotta or concrete tiles, this can: reduce tile lifespan, void manufacturer warranties, cause porous tiles to crack in cold snaps, and block gutters with debris. Algae growth (the black streaking on many Perth roofs) is also a sign of moisture retention.

Roof Cleaning Methods

Pressure washing: Effective for removing built-up grime quickly. Must be done carefully on terracotta tiles — too much pressure strips the protective glaze. Not recommended for older or fragile tiles. Soft wash: Lower-pressure application of biodegradable cleaning solutions. Safer for tiles and more effective at killing lichen and algae at the root, preventing faster regrowth. Treatment with biocide: After cleaning, a biocide treatment inhibits regrowth for 3–5 years.

How Often to Clean Your Perth Roof

Tile roofs: every 3–5 years, or when lichen/moss is visible. Colorbond roofs: less frequent — typically every 5–7 years, or an annual rinse with a garden hose. Homes near the coast or under trees: more frequently.

Roof Cleaning Costs in Perth

A typical Perth home: $500–$1,500 depending on roof size, pitch, access, and cleaning method. Biocide treatment: add $150–$400. Get 3 quotes — pricing varies significantly between operators.