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How To Clean Your Composite Deck

  • Henry
  • September 25, 2021

Cleaning Composite Decking

Composite decking offers little or no maintenance compared to regular wood or timber decking. You still need to take care of your composite decking, but nothing compared to maintaining regular wood decking.


Don’t let liquid spillages sit on traditional, first-generation composite decking. Wipe them away with a damp sponge or cloth and sweep clean with a soft brush. Composite decking is made with recycled plastics and wood fibres. Hence, dirt and dust are easily absorbed into the boards after rain or snow


Avoid water puddles building up on your decking, which can lead to increased fading over time or increased moisture absorption that leads to cracks.

floor brush

A quick hosedown with hot soapy water and a soft brush will ensure your decking looks great for decades to come. There is no need to worry about the yearly task of resealing, staining, dealing with splinters, or even worse, slipping on your old wooden deck.

Below are a few ways and types of cleaning solutions to help keep your composite decking looking great and to ensure little maintenance for years to come. Following these tips will help you keep your new composite decking standing up against weathering and mould and mildew build up and give you a great place to relax and enjoy your deck and garden every day.

How to clean your composite decking

Cleaning your composite decking is essential in order to keep your decking looking beautiful all year round. You must ensure that you clean your decking correctly so that you don’t damage the surface finish of the decking boards.

Follow our step-by-step guide below on how to correctly clean your composite deck easily and conveniently. 

  • Always remove any furniture before cleaning. Neglecting certain parts of the decking can spread damage to adjacent areas. So, when cleaning your composite decking, make sure to clean the entire decking area.  
  • Brush the decking before a thorough clean. It makes the cleaning process faster and removes any unwanted dirt and debris.  
  • Mix ammonia-free soap and lukewarm water in a bucket. Regular dishwashing liquid will work to remove any stains from your composite decking without causing damage to the deck surface. 
  • Never use harsh chemicals or bleach, which will damage your composite decking surface.  
  • Wet the decking with a soapy solution and lightly scrub it with a soft brush. A similar brush used for washing cars is ideal.
  •  Thoroughly rinse with water from a garden hose.  

As your composite outdoor living space will most likely get utilised all year round due to its resistance against the elements, it could likely be prone to stains or marks over time. If any staining occurs on your decking surface, you must act immediately to avoid any permanent staining.

Additionally, you will need to ensure that you don’t cause further damage to the decking surface by using the wrong products or cleaning too harshly. We have compiled a do’s and don’ts guide for your peace of mind when maintaining your decking. 

Types of Composite Decking Cleaner

All outdoor decking requires cleaning. Composite decking is ultra-low maintenance, but this doesn’t mean it is maintenance-free. Some general cleaning will ensure the lifespan of your composite decking for decades to come.

You can use different kinds of cleaners to make your decking sparkling clean. But not all types of cleaning products are good for composite decking. You will not want to use a kind of cleaner that can damage composite decking. Choosing the best cleaner for wood-plastic composite is important to maintain its appearance and life span. Additionally, you can purchase cleaning solutions from stores or choose to make your own cleaner.

Regular cleaning of your composite decking will not only retain its beauty and look attractive, but it will also prevent the growth of mould. Cleaning composite decking is easy. You will just require the correct cleaning solution for the job. So, What type of homemade cleaning solutions are they? and what are the correct tools to clean your composite deck with?

1 Ammonia-Free Liquid Dish Washer

If you have a dishwasher liquid at home that is free from ammonia, you can use it for your composite decking. To wash your deck, you can mix the liquid dishwasher with warm water and use it to clean your decking. Add about one tablespoons of the dishwasher liquid to 2 litres of warm water. Then use the mixture for your composite deck.

2 Vinegar

Vinegar won’t damage composite decking, as long as its diluted; therefore, diluted vinegar is safe for use on decking. Deck owners can use apple cider vinegar to clean their decking.  Additionally, you can also use white vinegar to wash your composite decking. To use vinegar as a cleaner for your decking, mix the vinegar with water. As a guide, mix a half cup of vinegar with 5 litres of water. Then use the mixture to scrub your decking. In addition, vinegar is also the best cleaner for removing mould on composite decking.

3 Baking Soda

Baking soda is also a good cleanser for composite decking. Cleaning your deck with baking soda is safe. Baking soda is not a harsh substance that can damage composite decking. When using baking soda to wash a composite board, sprinkle some baking soda on the decking. After sprinkling it on the decking surface, you can now scrub the decking with a soft bristle brush and rinse clean thoroughly.

4 Soft Brush

A soft-bristle brush is effortless to use and perfect for sweeping away dead leaves and debris from your composite decking. This way, you will get rid of leaves, twigs, and dirt on your deck surface. Getting rid of dead leaves off your decking surface will prevent any chance of moisture build up, which can lead to mould and algae growth.

With a soft bristle brush, you can remove stains on your deck surface. A soft bristle brush is a good composite decking accessory to use for scrubbing together with liquid dishwasher soap and hot water if you notice any food or grease stains on the deck surface.

Besides that, the brush is also useful in removing mould and algae from your composite decking. After applying white vinegar and baking soda to your decking, scrubbing the mildew with a brush will easily eliminate the mould. Additionally, homeowners can also use a soft bristle brush to scrub their decking if there are bird droppings on it. You first have to rinse the decking with water to soften the bird droppings before scrubbing it.

5 Plastic Shovel

Use a shovel with a plastic edge to prevent scratches on your composite decking and scoop away any build up of snow or ice.

6 Garden Hose

Finally, a garden hose can be used to easily remove dirt and debris from your decking. A garden hose is easier to use and more gentle on composite decking than a pressure washer.

7 Pressure Washing Your Composite Decking

If used correctly, Ultra Decking does recommend using a pressure washer on a very low setting no closer than 8–12 inches to the composite decking area. A high-pressure washer can open the surface material, causing issues like chipping, sun damage, and mould staining. 

Please note: A garden hose with a quick sweep using a soft brush will be more than enough to keep your deck looking as good as new.

What Is the Best Cleaner For Composite Decking?

The best cleaner for wood-plastic composites should be a type that does not contain harsh chemicals. There are a lot of cleaning solutions in stores; make sure you choose a type that is gentle for composite decking.

Composite decking is different from other kinds outdoor products. A cleaner that is suitable for washing other materials may not be suitable for composite boards. For instance, while bleach may not affect some materials, it is dangerous to use on composite decking as bleach can permanently damage wood-plastic composites.

The best cleaner for composite decking should be eco-friendly. Vinegar and baking soda is one of the best homemade cleaning solutions for tough marks and mild stains. As previously mentioned, it is important to note that undiluted vinegar should not be used to clean composite decking. Ensure you dilute the vinegar with water before using it to clean your deck.

Another good cleaner for composite decking is compo clean, this we have trailed and tested with the help of some of our customers and its able to produce some great results.

How to Correctly Clean Your Composite Decking:

Avoid Harsh Chemicals

As mentioned above, refrain from using harsh chemicals, bleach, or pressure washers with excessive pressure, as these can damage the composite material. There is no need to use bleach or chemical-based cleaners, as you can do more damage than good and alter the structural integrity of your composite decking.

Many customers don’t regularly clean their composite decking and let dirt and stains build up, then decide to thoroughly clean their decking with harsh chemical cleaning products, which leads to damaging the protective layer that composite decking has, which then affects its lifespan.


Implement a regular cleaning routine

Keep on top of your simple cleaning and there will be no need to do a thorough and deep clean, as like anything done in small amount stops the requirement for a large deep clean. Where possible, watch out for the accumulation of leaves, etc., to stop the growth of mould.

Aim to keep your composite decking as dry as possible to stop water pooling and water marks from occurring. Always follow the manufacturer’s guidelines to avoid voiding your warranty. As a rule of thumb, regularly cleaning your composite decking monthly is advised.


Remove dirt and Debris

To retain the appearance of your composite decking, you need to reduce the build up of bacteria that can lead to mould growth and, in turn, surface damage.

Not only will removing the collection of dirt or leaves keep your decking looking tidy and more aesthetically pleasing, but it also prevents rotting through the accumulation of moisture that gets trapped in debris on your decking surface.

As mentioned above use a soft bristle brush or plastic shovel (not metal) to avoid scratching your composite boards.

How Do I Remove Dirt From My Composite Decking

First, use a broom or soft brush to remove excess leaves and debris. This will leave the surface area ready to be cleaned. Use a garden hose or apply a bucket of warm water to clean the surface area of your decking. Once applied, use a soft-bristle brush to scrub the surface of the decking area. Then prepare a bucket of warm, soapy water and apply it; leave it to stand for several minutes; then simply wash it down with a garden hose or bucket of clean water and leave it to dry.

Composite decking is not difficult to clean. You can clean it easily when compared to wood decking. Wood-plastic composite decking requires a cleaning solution, water, a bucket, a brush, and a garden hose with a water nozzle. It also requires scrubbing the composite decking depending on the kind of stain on the decking.

If your composite decking is dusty, you can sweep it with a soft brush and mop it with soapy water.

For oil and grease stains on the decking, you can pour soapy water on the spot and scrub the composite decking with a bristle brush. For stubborn stains, a mix of bicarbonate of soda and vinegar should do the trick.

Diluted vinegar will also remove mould from your composite decking. Pour diluted vinegar on the mould and use a soft bristle brush to scrub it.

Long Awaited Deep Clean

In some instances, we have come across customers who have not maintained their decking at any point for a number of years.  In almost all cases, these customers have performed all the above cleaning tips and advice to revive or remove stains from their composite decking without success. That said, we are aware of customers who have successfully turned around their stained and dirty composite decking with the use of a deck restorer product called Compo-Clean. That said, successful restoration of your composite decking would depend on the decking’s location and surroundings, the number of years of neglect and the level of dirt and staining engrained in the decking boards.

Why Does This Happen

Like almost all outdoor products, if you neglect to perform regular maintenance and cleaning on your deck whatsoever, don’t expect it to look new and last for longer than expected. With years of neglect and failure to clean your decking regularly, you should expect to see stains and marks appearing on the deck surface. These will be very difficult to remove, especially with first-generation composite decking. In the main, this is due to the production and manufacture of decking boards with the use of recycled plastic and wood fibres.

Yes, composite decking is engineered to withstand nature’s elements; however, it still has wood in its structure and will therefore carry over some of the drawbacks associated with wood. This means you should expect some colour fading, although not to the same extent as wood by any measure. Additionally, if not regularly maintained, expect an accumulation of mould, mildew, stains, and algae. So clean it and keep to a regular cleaning schedule.

Colour Fade Reviver

first-generation composite decking that doesn’t benefit from a capped or shielded protective layer. As previously highlighted, its top surface is made from wood fibres and powders. Similar to the drawback of wood, you should expect to experience colour fade. Don’t be too alarmed at this and don’t think it is in the same realm as wood and should be completely bleached. The colour fade will noticeably lighten compared to its original colour at the time of installation. With that in mind, we are often asked by customers what can be used to revive the decking board’s colour.

The best product in our experience would be Compo-Reviver, which comes in shades of grey or brown. For successful results when using Compo-Reviver, thoroughly clean your decking before use and allow it to dry. Apply Compo-Reviver with a roller or brush to perform a deeper clean and colour restore. This is currently the best solution we have tested to revive a neglected composite decking area. You may not be able to restore the decking’s original colour but it will definitely provide an improved, almost like-new colour appearance. As with any paints, sealants, or stains, you should always test in an inconspicuous area to confirm their suitability before using them on the entire decking surface.

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