How to clean decking with or without a pressure washer

Get your decking looking as good as new for the summer season with our step-by-step guide
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  • As the weather warms up, we’ll all want to spend more time in our gardens making now the perfect time to get things spic and span. First up is the deck! If you’re fortunate enough to have decking, Follow our easy step-by-step guide on how to clean decking to get your outdoor entertaining zone ready for the months ahead.

    Whilst summer hasn’t quite set upon us, now is a good time to clean the decking. An annual wash during the winter months can breathe new life into any garden decking idea. Preserving the integrity of the wood and ultimately help to prevent costly repairs.

    ‘As decking is outdoors, it is constantly exposed to the elements, particularly in winter, which can take its toll,’ says Matthew Brown, Technical Consultant for Sadolin & Sandtex. ‘Exposure to the elements can lead to an accumulation of dirt, mould and algae. If maintenance isn’t carried out during the winter months, this of course creates a bigger job further down the line.’

    So start now and follow our easy steps on how to clean decking with or without a pressure washer.

    How to clean decking: Step-by-step guide

    zoned garden with decking area

    Image credit: Future

    A decking area provides a dedicated entertaining area for any outdoor space – whether its attached to the house, at the end of the lawn or even in the form of a balcony, decking creates a welcoming spot to enjoy the company of friends, or relax on your own.

    Unfortunately decking can end up being slippery (and quite dangerous) if it’s not taken care of. Algae and moss can grow and form over the surface of the decking, making it difficult to walk on. You can stop the growth getting this bad with regular maintenance. But if it’s already set in don’t fear, as there’s plenty you can do to get it looking clean and new again.

    Moss or algae aside, a garden deck, wooden or composite, needs a good clean now and then. And how to clean decking and deck railing ideas is actually really easy when you follow some simple steps; it doesn’t require lots of expensive products, either.

    1. Get prepared for how to clean decking

    Start by removing everything from your decking – furniture, pots, your barbecue, ornaments, and everything else. Pop them somewhere where they won’t be in the way for a day or so.

    Whilst the weather is unpredictable, it’s best to work when the day is clear, and the deck is totally dry; allow a few days to pass since a downpour. Give the complete decking a thorough sweep, using a brush to get debris from between the cracks as best you can.

    There’s a smart ‘Decking Brush Set’ from Coopers of Stortford that boasts a wide, curved brush-head to first gather leaves and debris. Then a rugged flat brush-head to scrub away decking moss and a compact head with a steel hook to turf out tough weeds and moss from between grooves – nifty!

    Buy now: Decking Brush Set, £29, Coopers of Stortford

    2. Apply a cleaning solution

    most common cleaning mistakes 3

    Image credit: Future / Polly Eltes

    For a gentler clean to remove surface dirt and cobwebs, you can use a solution of washing up liquid in warm water. Be careful not to over scrub with anything harshly abrasive, and avoid rubbing against the grain, as that can leave marks.

    ‘Whilst you can use soap water, a specialist product such as Jeyes Patio and Decking Power is likely to be more effective to get rid of stubborn moss and algae,’ says Sophie Herrmann, spokesperson for Jeyes Fluid. ‘Mix it with water, pour it on and leave it to do its work.’

    Be sure to follow the manufacturer’s instructions on how to apply, timings and how to rinse away.

    3. Blast away grime with a pressure washer

    Depending how much moss and algae has built up will determine whether or not you need the addition of a pressure washer. You could use the cleaning solution alone, or use a power washer as well.

    ‘Tackling your decking with a pressure washer will spray away any moss and grime that might have built up,’ says Sophie Hermann. ‘Ensure that the setting on the pressure washer is suitable for your decking. Otherwise, it could potentially damage the surface of the decking’

    4. For an even deeper clean, use a stripper

    If your decking is particularly dirty, then a more stringent cleaning may be required. Ronseal Decking Stripper will leave your decking pristine. ‘For this, you’ll need to wear some gloves and give the tin a shake before use,’ says Jimmy Englezos, Senior Product Manager for Ronseal.

    ‘Apply the stripper to your decking with a decent sized brush – don’t be shy and ensure you apply a thick layer. It takes around 30 minutes to work. However, if it’s a hot day you’ll need to keep an eye of patches that are drying out and re-apply a layer where needed. Keep scrubbing with warm water and then wash it all off with a hose, and you’re done!’.

    Buy now: Ronseal Decking Stripper, £51.65, Amazon

    How do I clean the decking without a pressure washer?

    patio decking area with garden bench and hurricane lanterns

    Image credit: Future

    If you don’t have a pressure washer, it’s not the end of the world. For a start, if you have a composite deck, you shouldn’t really be using a pressure washer anyway – read on below to find out why. And for a wooden deck you can still get it looking sharp with some regular household cleaning products and some elbow grease.

    Depending on the dirtiness of your decking and how much mould and mildew has formed, you could do just as good a job with washing liquid detergent. Pour four litres of warm water into a bucket and stir in 250ml of laundry detergent. Apply the warm solution liberally onto the already cleared and swept deck. Work it into the surface with a broom. Allow the solution to sit on the decking for ten to fifteen minutes and then rinse thoroughly using your garden hose.

    Or you could try Cuprinol Decking Cleaner which is a powerful detergent specifically formulated to remove dirt, grease, algae and mould.

    How do I clean composite decking?

    Unlike wooden decking, composite alternatives actually require less regular maintenance so the task isn’t an unduly difficult one. According to composite decking experts, NeoTimber, decking of this kind can actually be cleaned using general everyday household products. In most cases, a light soapy solution applied and then rinsed with a garden hose on a light setting is adequate for a composite deck.

    ‘There aren’t any magic solutions or treatments that we’d recommend for treating your composite decking,’ the NeoTimber experts say. ‘In fact, with a bit of elbow grease, household cleaning items will be sure to do the trick and get your composite deck clean and tidy ready for the summer months.’

    Outdoor bar on raised platform

    Image credit: Future PLC

    Start by clearing the deck of all items. Brush away any debris from nooks and crannies by giving the surface a thorough sweep. Next, mix a bucket of warm water with washing up liquid to create a warm soapy solution. Apply directly onto the deck and clean with a soft bristled brush – a clean, dry broom will do the trick. Use a soft cloth or sponge in hard-to-reach areas, then rinse and allow to dry.

    One thing you should definitely not do is use a pressure washer on a composite deck. It’s softer than natural wood and can be marked and damaged more easily as a result. ‘Depending on the material, a power washer can scar boards if the pressure is too high,’ reveal experts at Trex.

    ‘If the power washing becomes too intense, it can even chip the material. If you damage your composite deck with a vigorous power wash, it can affect the warranty, which is generally not covered.’

    They recommend a routine clean of your decking every three to six months to clear away dirt, mud and soil that can accumulate and sit on your composite decking over the course of time.

    How do I keep my decking looking good for longer?

    Once you’ve spent the time cleaning, scrubbing and painting your decking, you’ll want to ensure it stays looking great for as long as possible. Whilst your decking will naturally take some general wear and tear from use, there are things you can do to limit damage.

    ‘To minimise damage, we recommend using rubber feet for any deck furniture,’ advice experts at Gripsure. ‘In addition, any planters, tubs or plant pots should be raised on blocks to allow air circulation and avoid mould growth. We also recommend using metal or plastic trays to catch and retain any excess liquid when watering plants.’

    For hot tub decking ideas consider the same principle, be mindful of water spills – perhaps seeking an underlay to protect the decking below.

    Outdoor living room with black decking and pergola, sofa and rug

    Image credit: Future PLC

    The final flourish to perk up tired decking is to give it a lick of fresh paint or use a stain. You might like to leave the decking untreated, but a coating of a protective product will keep it looking fresh for longer. A layer of protection means it’ll be able to withstand mould, algae and mildew. Ensure the decking is totally dry from its cleaning before you start, and brush away any leaves or debris that might’ve found its way there since cleaning.

    You can find garden paint ideas and stains in a range of colours, which will totally transform the decking. ‘Sadolin’s new Garden Colours Range consists of eight beautifully subtle shades, that can be divided into four on-trend colour families – green, blue, grey and neutral – meaning there really is a palette to suit every style’, says Matthew Brown, Technical Consultant for Sadolin.

    Ronseal also has a great palette of colours available in its Ultimate Protection Decking Paint. We particularly loves Sage, which will achieve a very on-trend look.

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