How Do I Get Mould off My Composite Decking?

M. John

Mould can distort the appearance of your decking. It will form a dark spot on your decking surface, thereby making it less appealing. Also, mould can even penetrate and damage a wood decking board. Not only is wood decking susceptible to mould growth, but mould can also grow on composite decking. If you notice mould growth on your Ultra Decking, getting rid of it should be the first thing to do. But, how will you get mould off your composite decking?

What Causes Mould Growth on Decking

decking board

Mould can grow on your decking if you fail to maintain it. Wood is more susceptible to mould growth than composite decking. But since composite decking also contains wood, mould will likely grow on it.

When dead leaves and twigs stay on your decking for a long time without you removing them, it will surely cause mould growth. Remember that outdoor deckings are exposed to the weather and fungus in the air. When debris stays on your decking for long, it will trap moisture. Composite decking boards that do not have an extra plastic coating on the outside will absorb this moisture, making it easy for mould to grow.

Also, mould will grow on your decking when fungus comes in contact with organic materials like leaves or twigs. If you allow leaves and twigs on your decking surface, you will start noticing a dark spot on it, which is a sign of mould growth. Mould can cause early damage to composite decking if you don’t get the mould off.

How To Get Mould Off Composite Decking?

Homeowners don’t need to wait for mould to grow on their decking before finding a solution. You can prevent mould from growing on your decking in the first place. But if there is mould already on it, there are ways you can get rid of it.

Install Newer Generation Composite Decking

Decking manufacturers have recently created a new generation of composite decking to resist mould growth. The newer generation composite decking has an additional plastic layer on its outer part. It differs from the older version which does not have an additional plastic coating.

The older generation of decking will absorb moisture, causing mould to grow on it. But the additional plastic coating on the newer version of the composite board prevents moisture from getting into the decking. If your decking surface is not wet, it’s unlikely that mould will grow on it. Also, since mould can not grow on plastic, the additional plastic layers protect the decking.

Clean Composite Decking Regularly

Leaving twigs and leaves on the deck can cause mould to grow on the surface. Regular cleaning of composite decking to eliminate leaves is necessary, especially in autumn. Use a broom or a rake to sweep the leaves and twigs on your composite decking. Do this regularly to prevent the leaves from piling up on your deck.

Use Vinegar to get the Mould Off

If there is mould already on your deck surface, use Vinegar. Vinegar is very effective in getting mould off composite decking. It is a natural mould and mildew remover.

First, rinse the entire decking with water to get rid of the moulds. Then, get a bucket and mix a part of the Vinegar with water. Pour the diluted Vinegar on the mould and use a brush to scrub it off your composite decking. Scrub the affected part until you have got rid of all the mould. Then rinse the entire decking with water.

Get Rid of the Mould With Baking Soda

Baking Soda is also effective in getting mould off composite decking. First, pre-rinse the decking to get some mould off. After you have pre-rinse the decking, sprinkle baking soda on the affected part and let it stay for a few minutes. Then use a brush to scrub the mould off the decking. You can mix baking soda with diluted Vinegar to get the mould off your decking for a better result. Scrub the deck surface till the mould is off and rinse the decking with water.


Homeowners can get rid of mould from their composite decking in different ways. Installing newer generation composite decking is the best way to keep mould from growing. Also, scrubbing the decking with Vinegar and baking soda effectively removes mould.


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