Key Takeaways -

• Scrubbing with a stiff brush is an easy and effective way to remove mould and algae, especially from deck grooves.
• A bleach solution can quickly break down mould, but it must be rinsed thoroughly and used with caution around plants.
• Oxygen-based bleach is a safer, eco-friendly alternative that cleans effectively without damaging wood or harming the environment.
• Commercial and DIY solutions, like algae removers or vinegar mixes, provide effective options for cleaning and preventing future growth.

Wooden decking can quickly become covered in mould and algae, especially in damp or shaded areas. This not only makes it look dirty but also makes it slippery and unsafe. The good news is that removing mould and algae is simple with the right methods.

This article will outline five simple methods to clean your decking, using both commercial products and DIY solutions. Each method is easy to follow and helps restore your deck’s appearance while keeping it safe to use.

Keep reading to find the best cleaning method for your decking. No matter how bad the mould or algae buildup is, these steps will help you restore and protect your deck with minimal effort.

Method 1. Manual Cleaning with a Stiff Brush

Scrubbing your decking with a stiff brush is a simple yet effective way to remove mould and algae. First, sweep any loose dirt and debris to ensure the surface is clear. Then, use a stiff-bristled brush and scrub firmly in circular motions, focusing on areas where mould and algae have built up.

Pay special attention to the grooves, as these tend to trap moisture and encourage growth. Cleaning your deck this way every few months, especially after wet seasons, helps prevent mould from spreading and keeps your deck safe and looking fresh.

Method 2. Using a Bleach Solution

A diluted bleach solution is a powerful way to eliminate mould and algae from wooden decking (1). Mix one bleach with four parts water and apply it evenly across the surface. Let it sit for 10–15 minutes to break down the mould before scrubbing with a stiff brush.

Once the stains loosen, rinse the deck thoroughly with clean water to remove any remaining bleach. Be mindful of surrounding plants, as bleach can be harmful. If you prefer a safer option, consider using oxygen-based bleach instead, as it is less harsh on the environment.

Method 3. Oxygen-Based Bleach for Eco-Friendly Cleaning

Oxygen-based bleach is a gentler alternative to traditional bleach, making it safer for pets, plants, and the environment. Unlike chlorine bleach, it doesn’t release harmful fumes or damage the wood. To use it, mix according to the product instructions and apply it evenly over the decking.

Let it soak for 15 minutes before scrubbing with a stiff brush to lift mould and algae. Rinse thoroughly with water to remove any residue. Popular brands like OxiClean and Deck Brightener offer effective solutions, providing a deep clean without the risks associated with harsh chemical cleaners.

Method 4. Commercial Algae Removal Solutions

For convenience, commercial cleaners specifically designed for decking can effectively remove mould and algae. Products like Pro-Kleen Spray and Walk Away, Roxil 200 Wood & Patio Cleaner, and SmartSeal Deck Cleaner are popular choices.

To apply, follow the product instructions for dilution, then pour or spray the solution evenly over the deck. Allow it to sit for 15–60 minutes before scrubbing stubborn areas if needed. Rinse thoroughly with a garden hose or a power washer on a low setting to remove any residue.

Method 5. Natural and DIY Cleaning Alternatives

For a chemical-free approach, household ingredients like oxygen bleach and vinegar can effectively clean your decking. An oxygen bleach solution works similarly to commercial cleaners but is safer for plants and pets.

Alternatively, a vinegar solution can be made by mixing one gallon of water with one cup of white vinegar. To use either method, apply the mixture generously over the deck and let it soak for 15 minutes. Scrub with a stiff brush to lift mould and algae, then rinse thoroughly with water.

Frequently Asked Questions

What’s the Best Way to Remove Green Algae?

The best way to remove green algae is by using a cleaning solution and a stiff brush. Oxygen bleach mixed with water or a commercial algae remover works well without damaging the wood. Apply the solution, let it sit for 15 minutes, then scrub and rinse.

Regular cleaning and better drainage help prevent algae from returning.

Can I Use a Pressure Washer on the Mildew on My Deck?

Yes, but use a low setting to avoid damaging the wood. A gentle spray lifts mildew while preventing splintering. Combine pressure washing with a cleaning solution for better results. Always rinse and let the deck dry completely before use.

How Do I Remove Moss on My Decking?

First, sweep away loose debris with a stiff brush. Apply a moss-killing solution, like diluted bleach or a commercial remover, and let it sit for 15 minutes. Scrub the surface, then rinse thoroughly with a hose. Keeping your deck clean and dry prevents moss from returning.

Conclusion

Regularly removing mould and algae from your wooden decking has many benefits, including improving safety, enhancing appearance, and extending its lifespan.

Whether you choose manual scrubbing, a bleach solution, oxygen-based bleach, commercial cleaners, or natural alternatives, each cleaning process is simple and effective. By maintaining your deck and preventing moisture buildup, you can keep it clean and slip-free all year round.

Sources -

1. https://trexrainescape.com/resources/how-to-clean-a-wood-deck-without-a-pressure-washer/