How to Look After Composite Decking: Cleaning Guide

Composite decking is popular for outdoor living spaces because of its durability, low maintenance, and pleasing look.

Unlike traditional timber decking, composite decking is more resistant to moisture, rot, and pest damage, making it a fantastic option for homeowners who don’t want the hassle of frequent maintenance!

However, like all outdoor materials, composite decking still requires care and attention to keep it looking its best and prolong its lifespan.

If you’re building a composite deck for your customer, you can recommend these simple steps to help them look after it and maintain its excellent condition.

Cleaning and maintenance

Proper cleaning and maintenance prolong a composite deck's lifespan and keep it in good condition.

Treating the deck with a cleaning solution removes dirt, grease, and mould and minimises the risk of long-term damage.

By following a rigorous cleaning schedule, your customer’s composite deck will stay looking its best and be less likely to damage.

Deck protection

Although composite decking is a durable and low-maintenance solution, like any outdoor structure, it requires protection.

Protecting a composite deck ensures it’s kept looking its best and reduces the long-term need for repairs.

Do you need to seal composite decking?

Unlike timber decking, composite decks don’t require sealant. This is because they already have an extra protective layer, thanks to the plastic fibres, making the deck more robust and resilient to potential damage.

How to clean composite decking

We recommend following these steps for effective composite deck cleaning for the best results.

1.   Clear – Remove any furniture, plants, and other items from the deck before cleaning.
2.   Sweep – Sweep away any leaves or debris.
3.   Rinse – Rinsing the deck with a garden hose helps loosen dirt, so it’s easier to remove later.
4.   Prepare – Prepare the composite deck cleaning solution according to the manufacturer's guidelines. If preferred, homeowners can also use warm water and mild soap.
5.   Apply – Use a soft-bristled brush or sprayer to apply the cleaning solution, working in small sections to ensure even coverage.
6.   Scrub – Scrub the deck while wet, paying particular attention to heavily soiled areas.
7.   Rinse – Wash away the cleaning solution with a garden hose.
8.   Dry – Allow the deck to dry completely before replacing furniture and accessories.
9.   Seal – After cleaning, homeowners can apply a composite deck sealer to help protect it from the elements and stains.

Homeowners can also use a pressure washer to clean composite decking. However, they must take proper steps to avoid damage. Advise your customer to use the correct pressure setting and keep the nozzle at least eight inches from the deck surface.

How often to clean composite decking

How often a composite deck is cleaned depends on several factors, including how often the deck is used, weather conditions, and the amount of debris on the deck.

As a general rule, cleaning a composite deck at least every six months is advisable to prevent debris and dirt from building up and maintain its appearance. The best time to clean a composite deck is during the spring or autumn months when the weather is mild.

Decks near lots of trees or under low-hanging branches may require more frequent cleaning and maintenance to clear away sticks and leaves. Similarly, if the homeowner’s deck is next to a regularly-used space such as a BBQ, swimming pool, or play area, they may find it needs more cleaning.

Encourage your customer to regularly inspect their composite deck for signs of dirt, stains, mould, and mildew. Cleaning these as soon as possible helps prevent further damage.

Tools and materials needed to clean composite decking

To clean composite decking, its recommended to use the following tools:

Stiff-bristled broom – used to sweep away debris and loosen dirt
Garden hose – for rinsing the deck
Soft-bristled brush – used to scrub the deck and remove dirt and stains
Bucket – for mixing the cleaning solution
Cleaning solution – either a specialised solution or a mixture of water and mild soap
Safety clothing – such as rubber gloves and goggles
Pressure washer – optional, for a faster and deeper clean

What can harm composite decking?

Several things can harm composite decking, including:

Weather conditions – such as rain, wind, and UV rays.
Mould and mildew.
Heat – dropping coal or hot ashes on a composite deck can cause discolouration and warping.
Moisture – composite decking can absorb moisture, which leads to swelling and warping.
Stains – such as food and drink spillages.
Marks and scratches – heavy furniture and pets can scratch composite decking, weakening the surface.
Pests – although composite decking is generally less appealing to pests like termites and rodents, they may slightly damage it.

A lot of these issues can be avoided if you choose to buy capped composite decking.

How to protect composite decking

Protecting a composite deck is the best way to prevent damage and make it last for years.

Homeowners have various options regarding composite deck protection, ensuring maximum safeguarding against weather conditions, pests, scratches, stains, and natural ageing.

Regular cleaning – Helps remove dirt and grime, preventing long-term damage.
Mop up stains – Addressing stains and spillages as soon as they happen reduces their impact.
Furniture pads – Prevents scratches and marks from furniture. Homeowners should also avoid dragging furniture across the deck and choose lighter pieces.
Not using shovels or sharp tools – Using shovels and sharp tools to remove snow and debris risks scratching the deck.
Protective mat – Can help protect damage from heat, such as hot coals and ash.
Sealant – Used for increased protection, particularly from moisture damage and staining.

How to repair composite decking

Composite decking provides a durable outdoor space, and is less likely to damage than timber decking.

However, ageing, extreme weather conditions, and general wear and tear can impact composite decking, making repairs necessary.

Before starting any repair work, it’s essential to ensure a clear decking area. This means cleaning any dirt and debris and removing furniture and other items.

Superficial scratches and scuffs can usually be sanded or filed out. Use a fine-grit sandpaper or metal file, and work in the direction of the grain to avoid additional damage. However, it’s really important to note you should not do this if you have capped composite decking.

Homeowners can treat stains with composite decking stain remover. Ensure they follow the manufacturer’s instructions and apply the remover to the affected area. They can also touch up small discoloured areas with paint that matches the composite decking.

Heavily damaged composite deck boards may need to be replaced entirely — advise the homeowner to refrain from undertaking this repair themselves, as this requires specialist assistance. A board of the same size and colour is also needed.

Final thoughts

Taking care of composite decking helps prolong the life of a home’s outdoor space.

After you’ve installed your customer's composite deck, provide them with the information outlined here so they can properly clean, protect, and maintain their decking.

Encourage them to regularly inspect the deck for signs of damage and stick to a maintenance schedule. Simple efforts such as clearing away debris, mopping spillages, and using furniture pads can go a long way in deck protection.

A composite deck can last many years with adequate care, providing a fun and relaxing place to enjoy a garden.