How To Clean Decking (In 5 Easy Steps!)

Your exterior decking isn’t just a platform – it’s a sanctuary for relaxation, socialising, and enjoying the outdoors. Over time, however, the elements can leave their mark, causing grime build-up, algae growth, and even structural issues. Maintaining your decking properly ensures it remains safe, inviting, and long-lasting, especially so for businesses like pubs and restaurants. Here’s an in-depth guide how to clean decking to keep it in top condition.

 

 

Cleaning your decking regularly does more than keep it looking good. By removing dirt, leaves, and mildew, you’re also protecting the structure itself. Moisture trapped by debris can lead to rot, while algae and moss create a slippery hazard, especially after rain. Regular maintenance keeps your decking sound, and safe for use by yourself, staff, patrons, etc. Cleaning your decking suitably also preps the surface for further treatments such as stains or oils.

When cleaning, it’s essential to follow safety precautions. Wear protective gloves and goggles to shield your skin and eyes from cleaning agents. Ensure the area is well-ventilated, and keep children and pets away until the decking has dried.

 

 

Depending on the surface, you may not need specialist equipment for spotless decking – just the right tools and a bit of elbow grease. A garden hose, soft-bristle brush, and a bucket will cover most jobs, but for tougher stains, consider a low-pressure washer. However, be cautious: high pressure can damage softwood or composite decking.

Product Spotlight

• Osmo Wood Decking Cleaner: This Osmo product is ideal for untreated or oiled wooden decking.
• C10: A fungicidal wash that is effective against algae, moss, and mould.
• Blackfriar Anti-Slip Deck Coating: Blackfriar has a product that adds a protective, slip-resistant layer.

 

 

Timber Decking

Wooden decking has natural beauty but requires regular upkeep to prevent rot and warping.

Common Issues: Algae build-up, discolouration, cracking.

Cleaning Tip: Avoid harsh chemicals that can strip protective oils.

Suggested Product: A diluted solution of Osmo Wood Decking Cleaner works well for routine cleaning.

Composite Decking

Composite materials are more resistant to rot but can still collect grime and mould.

Cleaning Approach: Use a mild detergent and soft brush; avoid strong jets from pressure washers.

Pro Tip: Rinse thoroughly to prevent soap residue that can attract dirt.

PVC and Plastic Decking

PVC decking resists water but can lose its sheen over time.

Maintenance Needs: Gentle scrubbing with non-abrasive cleaners.

Avoid: Abrasive tools that scratch the surface.

 

 

1. Clear the Space

Move furniture, planters, and décor off the decking to give yourself a clear working area. Sweep away any loose dirt and leaves.

2. Apply Your Cleaner

Dilute your chosen cleaner according to the manufacturer’s instructions. For timber decking, apply Wethertex C10 Fungicidal Wash evenly with a sprayer or mop. Composite and plastic decks benefit from Osmo Wood Decking Cleaner, which can be applied with a mop or soft brush.

3. Scrub the Surface

For stubborn stains, scrub using a soft or medium-bristle brush. Pay attention to corners and areas under railings where grime can build up.

4. Let the Solution Work

Allow the cleaner to sit for 30 to 60 minutes. Keeping the surface moist prevents the cleaner from drying out prematurely.

5. Rinse Thoroughly

Use a garden hose or a pressure washer set to low pressure to rinse away the cleaner. Start at one end of the decking and work systematically to avoid missing spots.

 

 

Pressure washers can be a blessing and a curse. They make quick work of grime but can damage softer woods or etched surfaces if used improperly.

Best Practices

• Use a fan-spray nozzle to distribute pressure evenly.
• Maintain at least 30 cm of distance between the nozzle and the decking surface.
• Avoid narrow streams of water, which can cause permanent grooves.

 

 

In the Spring and Summer, dust, pollen, and bird droppings can quickly collect. A light wash every few weeks prevents build-up.

In Autumn, falling leaves can trap moisture and stain your decking. Sweep regularly and apply a fungicidal wash to prevent further biological growth.

In the Winter months, snow and ice can weaken decking boards. Use a plastic shovel for snow removal and avoid salt, as it can damage wood fibres.

 

 

Once your decking is clean, it’s time to apply protective treatments. Sealing or oiling the surface helps repel moisture, restore natural oils, and prevent UV damage.

Protective Coating Suggestions

• Blackfriar Anti-Slip Deck Coating: Adds a durable, anti-slip finish.
• Osmo Decking Oil: Deeply penetrates wood to enhance its natural grain and protect against cracks.

Applying these treatments once a year keeps your decking looking its best and prevents long-term damage. Of course, you can also paint decking to protect it from exposure to the elements, with 5,000+ colours and shades available in smooth finishes and also anti-slip formulas.

 

 

Be mindful of the environment when cleaning your decking. Avoid washing chemical cleaners into storm drains, and opt for biodegradable products when possible. Store unused cleaners in cool, dry places and dispose of them according to local regulations.

 

 

Discolouration and Stains

Cause: Water or dirt build-up.

Solution: A thorough clean with a decking-safe product, followed by a water-repellent sealer.

Algae and Mould

Cause: Damp, shaded conditions.

Solution: Apply C10 Fungicidal Wash from Wethertex and increase airflow by trimming overhanging plants.

Cracks and Splinters

Cause: Seasonal expansion and contraction.

Solution: Sand down rough areas and apply Osmo Decking Oil to rehydrate the wood and prevent further cracking.

 

 

Public spaces such as pubs, gardens, parks, and restaurant terraces also benefit from regular decking maintenance. These areas experience heavy foot traffic, making them prone to dirt accumulation and wear. A clean and well-maintained deck enhances the overall customer experience, creating a safer, more welcoming environment.

In pubs, restaurants and beer gardens, a clean, vibrant deck serves as a separation from the dirt or concrete below, creating a much more manageable outdoor environment for customers, or expanding on the existing space. Keeping this area well-maintained is crucial, as the constant foot traffic can wear down the deck over time and create an unsightly or potentially unsafe surface.

These factors also apply to other outdoor spaces, such as parks and nature trails. These decks are especially prone to the accumulation of dirt, frequent foot traffic, and are often constantly exposed to the elements. Safety is paramount here, as even a slip could lead to a serious accident in some remote spaces. As such, ensuring these decks are properly cleaned and protected against the weather will greatly improve the experience for visitors. On this point, slippery timber can be transformed with the use of anti-slip decking strips, which are quick and easy to install with no need to cordon off the area from use.

 

 

Clean and well-maintained decking transforms your outdoor space into an inviting haven. By following these steps and using quality products from Rawlins Paints, you can enjoy your decking year-round without fear of slippery surfaces or costly repairs.

Routine care goes a long way – spend a little time each season to keep your decking in peak condition. Whether you’re preparing for summer gatherings or winter-proofing your space, your efforts will pay off with decking that stays beautiful for years to come.

We also recommend reading: Blog: How To Clean Exterior Wood