Cleaning Decking Without a Pressure Washer

The brush and cleaner method, step by step

Start by sweeping the deck clear of loose debris, leaves and dirt. Apply a dedicated decking cleaner or a diluted algae and mould treatment across the surface, working in manageable sections, and leave it to dwell for the time stated on the product, usually somewhere between ten and thirty minutes.

Scrub with a stiff bristle deck brush, working along the direction of the boards rather than across them, paying particular attention to any visibly green or slippery patches. Rinse thoroughly with a garden hose, using a spray attachment on a firm but not aggressive setting, and allow the deck to dry fully before walking on it or applying any further treatment. Pay particular attention to the gaps between boards, since debris and algae trapped there is often what feeds regrowth even after the visible surface looks clean.

Tools and products needed

A stiff-bristled deck brush, a bucket, a garden hose with a spray nozzle, and a decking cleaner or algae treatment suited to your deck type cover everything needed for this method. Knee pads or a scrubbing pole for larger areas make the job considerably easier on bigger decks. A stiff-bristled broom head on an extendable pole is a worthwhile addition too, saving your knees and back on a larger deck without needing to invest in specialist equipment.

Composite decking cautions

Composite decking, made from a mix of wood fibre and plastic, behaves differently from solid timber. It does not need oiling or staining the way timber does, but it can still develop a surface algae film, and using the wrong cleaning product, particularly anything with strong solvents or abrasive cleaners, can dull or discolour the surface coating some composite boards have. Always check the manufacturer's cleaning guidance for the specific composite product installed, since formulations vary between brands. A soft-bristle brush rather than a stiffer timber-rated one is generally the safer default for composite, since some capped composite finishes scratch more easily than people expect.

When a pressure washer or professional clean makes sense

For a large deck, heavily established algae, or timber that is already worn and needs a bit more restoration than a routine clean, a professional soft wash service achieves a more thorough result without the risk of DIY pressure washer damage. It is also worth considering if the deck has never been properly cleaned since installation, since a brush alone may struggle with years of built-up growth.