Removing Algae from Decking

Green algae on your decking not only looks unsightly, it can actually be very damaging to the wood, and can even pose a hazard to yourself. If your decking has started to develop a green, slimy film then you could be suffering from algae growth.

In this guide we’ll be exploring ways to effectively remove algae from your decking, and finding methods to stop it from returning.

What is Green Algae

Green algae are microorganisms that thrive in aquatic environments. Green algae often presents as a green slime, and is not to be confused with other biological organisms such as moss or mould.

Moss is also green and grows in a similar environment to green algae, however, it is soft and fuzzy to the touch. Mould is also common on decking, but mould is often characterised by greenish-black streaks on the wood. Mould spores can be very dangerous to humans and animals when inhaled and should be dealt with swiftly.

Reasons Why Algae Removal on Decking is Essential

There are many reasons why you should remove green algae from your decking, from preserving the integrity of the wood, to ensuring your own safety. Let’s look at the different reasons now:

Moisture Damage: Algae is an aquatic microorganism that retains a lot of moisture, this means that as it sits on the surface of the decking, the moisture is able to seep into the wood which can cause the wood’s structural integrity to deteriorate. Too much exposure to moisture can cause the wood to swell or warp, which can result in cracks, or can even cause wood rot and delamination.

Slip Hazard: Algae causes a green, slimy film to form on the surface of the decking which can become extremely slippery, especially in wet conditions. If your decking receives fairly heavy foot traffic, then the chances of somebody slipping and injuring themselves is fairly high. Removing the algae will prevent any accidents that could result in serious injury.

Fast Regrowth: Algae has the ability to grow back very quickly if you haven’t cleaned the surface properly. In order to stop green algae from being a recurring problem, using an effective cleaning solution is imperative. If you cannot completely remove the algae then you will have to implement a regular cleaning schedule to minimise spread.

Ugly Appearance: Algae looks dirty and unkempt, which detracts from the overall beauty of your decking. Ensuring frequent maintenance of your decking will allow you to enjoy your garden to the fullest.

Reasons Why Algae is Common on Decking

Algae is a common occurrence on decking due to a few factors, the main ones being:

Moisture: Algae needs moisture to grow. Water that is present on your decking from rainfall, watering plants etc can create the perfect breeding ground. Ensuring proper drainage is essential to prevent water from pooling on the deck’s surface.

Shade: Algae is prone to shaded areas, so decking that is shaded by trees, fences or other structures may be conducive to algae growth. Increasing sunlight exposure will limit future growth. If this is not possible, then regular cleaning is essential.

Debris: Algae growth is benefitted by the accumulation of organic debris such as leaves, branches, animal droppings etc as they can trap moisture and block sunlight. Sweeping away biological matter will help to prevent algae growth from spreading.

How to Remove Algae from Decking

There are a few different methods that can be utilised for removing algae on decking. We will now explore some varying options and their effectiveness.

Commercial Algae Remover

Arguably the most effective method for removing algae from decking is to use a commercial, professional cleaner. These products are specially formulated to remove algae, and also offer extra protection against future growth.

GK Decking Cleaner is a professional-grade, high-performance solution that has been specially designed for the effective removal of organic and micro-biological contaminants such as algae, lichen, mould and bacteria from decking.

GK Decking Cleaner is free from solvents, acids and bleach, formulated to be gentle on surfaces while maintaining strong cleaning power due to its superior DDAC formula. It does not discolour treated surfaces, making it ideal for preserving the original appearance of decking and other exterior finishes.

Bleach

Mixing bleach and water will create a cleaning solution that effectively kills algae. Mix one part household bleach with four parts water in a plastic bucket and add a teaspoon of dish soap to the mixture.

Before applying the solution, clear the deck of any objects and sweep away loose debris. Wet the deck, apply the solution to a small section at a time, let it sit for 10-15 minutes, then scrub with a stiff brush and rinse thoroughly with water.

Always wear gloves and eye protection, and shield plants and grass from the bleach. Bleach does provide some protection against future growth. It can cause discolouration to the wood so should be used with caution.

White Vinegar

Mixing white vinegar with water creates a cleaning solution that effectively kills algae. Mix one part white vinegar with one part water to create a solution and apply it to the affected areas.

Allow the solution to sit for 15-20 minutes to let the acetic acid break down the algae, then scrub the surface with a stiff-bristled brush and rinse the decking thoroughly with clean water to remove the algae and any residue.

Vinegar can help remove algae from the decking, but it won’t provide lasting protection. Acid can also be damaging to wood, so use this method with caution.

Pressure Washing

Using a pressure washer on a low-pressure setting will remove the surface algae, but this method is not recommended for lasting protection. Water is also a key factor for algae growth so remaining algae may spread on the decking if the water is left to pool.

High-pressure settings may damage the wood, so this method should be used with caution.

How to Prevent Algae Regrowth on Decking

Cleaning your decking is important to maintain its appearance, but there are steps you can take to limit algae regrowth, and keep it away for longer.

Reduce Exposure to Moisture, Shade and Debris

We highlighted that moisture, shade and organic debris are key factors in the growth of algae, so limiting the decking’s exposure to these factors will prevent the growth of algae.

Ensure that your decking has appropriate drainage to stop water from pooling on the surface. If possible, cut back trees and move structures that shade your decking so that sunlight exposure is increased. Regularly sweep away any debris such as leaves and branches that fall onto the decking.

Seal the Decking

Once you have removed the algae from your decking, applying a seal will create a barrier on the surface to stop algae from returning.

GK Invisible Wood Sealer is a professional grade, water-based sealing solution designed specifically for use with decking and other wood structures. This ready-to-use sealer penetrates deep into wood, creating a robust defence against moisture and rot, while its algae-repelling formula keeps your wood surfaces pristine.

Summary

The best solution for algae on decking removal is a professional-grade cleaner such as GK Decking Cleaner. This high-performance cleaner has been specially formulated to remove algae and provide lasting protection.