How do you clean wooden decking safely?

Apply a decking cleaner, allow 15-20 minutes dwell time, then scrub with a stiff brush or use a pressure washer on a low setting (1,000-1,500 PSI) with a wide-angle nozzle. Always work along the grain to avoid raising wood fibres. Rinse thoroughly afterwards.

Should I oil decking after cleaning?

Yes, oiling wooden decking after cleaning is essential for protection. Allow the decking to dry fully (24-48 hours) before oiling. Apply a quality exterior decking oil in thin, even coats. This protects against UV damage, moisture absorption and premature greying.

How much decking oil do I need?

Decking oil typically covers 8-12 m² per litre. We use 0.08 litres per m² as an average estimate. New or heavily weathered wood absorbs more oil. Apply two thin coats rather than one thick coat for best protection and appearance.

Can I pressure wash composite decking?

Yes, but use a lower pressure setting (1,200-1,800 PSI) and a wide-angle nozzle (25° or 40°). Keep the lance at least 20cm from the surface and avoid concentrating on one spot. Check the manufacturer guidance — some composite decking warranties are voided by pressure washing.

CleanCalcs

Decking Cleaning Calculator

Calculate cleaning time and product volume for wooden or composite decking.

Decking Area

Total decking area

Decking Type

Cleaner Cost per Litre

Optional

Apply decking oil after cleaning

Oil after cleaning (wood only)

How We Calculate This

How the calculation works

Cleaning time and product volume are calculated based on deck area and material type.

Coverage rates (m² per hour)

Softwood: 6 m²/hr
Hardwood: 8 m²/hr
Composite: 10 m²/hr

Formulae

Cleaning time = area ÷ coverage rate

Cleaner = area × usage rate per m²

Oil = area × 0.08 L/m² (if oiling)

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities and timings for your specific situation.