How to Clean Decking

It’s easy for dirt and algae to build up on your decking, and keeping your deck clean and tidy can seem daunting, especially if you’ve got a particularly large outdoor space. Cleaning a deck is quicker and easier than you might think, whether you opt for a pressure washer or a broom and a bit of elbow grease. So, whether your decking has had a lot of use in the summer or it has taken a beating by the winter weather, this guide will show you how to get your deck looking as good as new.

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You should clean your decking twice a year (after summer and winter) to improve appearance, prevent mould, and avoid slippery, unsafe surfaces.
To prepare for cleaning your decking, you should clear any furniture and debris. Then clean either by hand using a gentle bleach or vinegar solution and a deck cleaning brush, or with a pressure washer set to medium.
You should let the deck dry fully after cleaning, then you can put furniture back or apply treatments to protect it for the season ahead.

Why should I keep my decking clean?

There are a few reasons why you should keep your decking clean, with the most obvious being aesthetics. Cleaning decking also helps to stop mould and mildew from creating slippery, dangerous spots on the wood, and it helps to prevent the wood from becoming waterlogged. Plus, there’s the hygiene element as cleaning stops harmful fungi from multiplying.

When should I clean my decking?

It’s best to clean your decking about twice a year; once after the summer, and once after the winter. You’ll also want to make sure you avoid cleaning your deck in wet weather so that the wood has the chance to properly dry afterwards.

How to prepare your decking for cleaning

Before you start cleaning, you’ll need to prep the deck. First, remove all furniture and planters, and use a stiff broom to clear away any loose dirt. It’s important to make sure you get into every nook and cranny of the deck, leaving nothing behind. You can then use a leaf blower or garden vacuum to clear out smaller pieces of debris. You may want to use a dustpan and brush for smaller, more awkward areas.

How to clean your decking by hand

If your decking is in a particularly bad state, you’ll need to apply a specialist cleaner designed for wood. Let this soak for 5-10 minutes before rinsing it off with a hose.

If your decking just needs a light refresh, you can achieve that with products that you already have at home.

Start by hosing down your deck to get rid of any excess dirt and dampen the wood, ready for cleaning.

Mix household bleach (preferably oxygen bleach rather than chlorine bleach) with water in a 1:5 ratio. Use a watering can to pour this over the decking.

Note: Only use bleach on timber decking, as it may damage plastic and composite decking.

If you’re concerned about pets or plant life being harmed, you can clean your deck using natural products. A mixture of white vinegar and water will work well.

With the cleaning solution poured onto the deck, scrub it into the timber with a scrubbing brush or broom.
Scrub in the direction of the wood and be careful not to scrub too hard and scratch the surface. Make sure to clean between the boards as this is where you’ll get the most build-up of debris.
Concentrate on areas with the most dirt. This will usually be high-traffic areas.
Leave for 20 minutes for the cleaning solution to take effect. You can also sprinkle some baking soda onto dirtier or more stained areas for greater cleaning efficiency.
After 20 minutes, rinse the deck off with a hose to remove any remaining solution or dirt.

How to pressure wash decking

There are a few things to consider before pressure washing your decking, the main one being the power of the pressure washer. Wood is a soft material so spraying with too much pressure can damage it. The ideal pressure for cleaning your deck is around 1,000 to 2,000 PSI. However, this’ll depend on your choice of pressure washer.

Use a fan nozzle or rotary attachment to create a wider, less concentrated spray and set your pressure washer to a medium power setting. You won’t want to use the highest power as this could damage the wood. If the decking is only lightly soiled, a lower power setting should do the job.

Use a wood-specific cleaning solution in the machine. Check the manufacturer’s instructions to see how your pressure washer works.

Top tip: It’s a good idea to wear safety goggles and clothes you don’t mind getting dirty as the grime can fly up as you’re cleaning.

There’s a technique to pressure washing that ensures you’ll get a consistent finish without harsh cleaning lines being left at the end. Practise using the pressure washer on an inconspicuous area of your decking, like somewhere in a corner that may usually be covered by furniture. This gives you a chance to work out what technique is best for your deck.

When cleaning decking, you’ll want to hold the nozzle no closer than 6 inches from the wood. This should give you enough power to clean off tough dirt without damaging the deck.
Work in straight lines, following the direction of the decking and the grain of the wood. Then overlap your cleaning pattern to avoid creating water lines.
Keep your settings consistent throughout the cleaning process. If you increase or decrease the power midway, you may be able to see the difference.
You should keep moving as stopping at one spot for too long can overload the wood with water, which can lead to damage.

What to do after cleaning

When you’ve finished cleaning and rinsing the whole deck, wait for it to thoroughly dry and then you can put back any furniture and accessories or even spruce up your decking with paint or treatment.

Having clean decking makes a huge difference to the look of your garden. Not to mention, it’s now ready for the harsher winter weather, or for summer outdoor entertaining. Just remember to prep the deck properly before cleaning, and – if you’re using a pressure washer – make sure you’re not doing anything to damage it.

FAQs

Dish soap and hot water will work well to clean your deck. Use it in the same way as any other deck cleaning product and scrub it into the decking with a brush, making sure to rinse afterwards.

A pressure washer is a quick and effective way to clean your timber decking, but make sure to use it on a low to medium setting as anything too powerful may damage the wood.

To clean off any algae from decking, you should first clear the decking before using either white vinegar or decking cleaner to scrub away the algae with a wire brush.