Here's why it happens:
- Moisture sits on the surface for longer during winter.
- Algae and mould begin growing in shaded or damp areas.
- Dirt and road grime settle into the pores of concrete and paving.
- Perth's sandy soil mixes with moisture to create dark surface stains.
This black build-up is not just surface dirt — it's living organic growth. Regular pressure washing helps prevent long-term staining and keeps your driveway looking clean all year round.
If your driveway is already black, a deep clean and optional sealing can restore it completely.