Composite decking has become a favourite choice for modern gardens, stylish, low-maintenance and built to last. But even the toughest materials need a little care now and then. Left unchecked, dust, algae, or food spills can spoil its appearance and even make the surface slippery.
The trick is knowing how to clean composite decking properly, without harsh methods that might do more harm than good. In this article, you’ll discover practical, safe and effective ways to bring back the colour and freshness of your decking. Simple steps, clear advice, so you can enjoy an outdoor space that always looks welcoming.
Why It’s Important to Clean Your Composite Decking
Keeping your composite decking clean isn’t just about appearances, it’s about protecting your investment. Regular maintenance prevents stains, moss, and algae from taking hold, which can otherwise make the surface slippery and unsafe.
By cleaning it properly, you also help preserve the original colour and smooth finish of your boards, so your deck continues to look as good as the day it was installed.
Most importantly, consistent care extends the overall lifespan of your decking. Instead of facing costly repairs or early replacements, you’ll save money in the long run while enjoying an outdoor space that feels fresh, safe, and welcoming all year round.
How Often Should You Clean Your Composite Decking?
Looking after your composite decking doesn’t have to be complicated – it’s all about building a simple routine. A quick sweep or blast with a leaf blower once a week (or at least monthly) will stop leaves, dirt, and debris from piling up.
Twice a year, ideally in spring and autumn, it’s worth giving your deck a more thorough clean to prepare it for the wetter and colder months ahead.
And don’t forget about those little accidents, food, grease or drink spills should be wiped away straight away. Spot cleaning prevents stains from setting in and keeps your decking looking fresh without much effort.
By staying on top of these easy steps, you’ll enjoy a deck that’s safe, spotless, and always ready for use.
What Not to Do When Cleaning Composite Decking
While composite decking is durable, the wrong cleaning methods can do more harm than good. Harsh chemicals like bleach or acidic cleaners should be avoided, as they can damage the surface and affect the colour of your boards.
Another common mistake is letting the cleaning solution dry before rinsing, this often leaves behind white streaks that spoil the finish.
If you’re using a pressure washer, keep it safe: stick to a low setting of up to 1,500 PSI (around 100 bar), fit a fan nozzle, and hold the lance at least 20cm away from the boards.
This way, you’ll remove dirt effectively without risking cracks or surface damage. By avoiding these pitfalls, you’ll protect your decking and keep it looking its best for years to come.
Tools & Products You’ll Need
Cleaning your composite decking doesn’t require fancy equipment, just a few simple tools you probably already have at home. With the right products, you can remove dirt and stains quickly without damaging the boards. Here’s what you’ll need:
- Soft-bristle brush or broom: gentle enough to protect the surface, strong enough to loosen dirt.
- Bucket of warm water: the base for any effective clean.
- Mild washing-up liquid or composite decking cleaner: safe solutions that lift grime without harming the boards.
- Garden hose or low-pressure washer: ideal for rinsing away dirt and soap.
- Optional: eco-friendly DIY solutions (vinegar or bicarbonate of soda): perfect for tackling tougher spots naturally.
With these essentials, you’ll be ready to keep your decking fresh, safe, and looking like new all year round.
Step-by-Step Guide to Cleaning Composite Decking
Cleaning composite decking may sound straightforward, but doing it the right way makes all the difference.
If you’re wondering how do you clean composite decking in the most effective way, this step-by-step guide will show you the best way to clean composite decking safely, without damaging the boards. Here’s the complete process to follow:
Step 1 – Clear the area
Before you begin, remove all furniture, plant pots, rugs, and decorations. Not only does this give you full access to the boards, but it also prevents cleaning solution from splashing onto items that could be stained or damaged.
Think of it as resetting your deck to a clean slate.
Step 2 – Sweep thoroughly
Take a stiff broom or leaf blower and clear away dirt, twigs, and leaves. Pay extra attention to the gaps between boards, this is where moisture often settles, encouraging moss or algae growth. By keeping these spaces free of debris, you reduce the risk of slippery patches and prolong the deck’s life.
Step 3 – Rinse the Decking
Give the surface an even rinse with a garden hose or, if you prefer, a pressure washer on a low setting. This loosens ground-in dust and makes the cleaning solution more effective later.
Think of it like pre-soaking dishes before washing them, it saves effort down the line.
Step 4 – Apply cleaning solution
Mix warm water with a few drops of mild washing-up liquid, or use a specialist composite decking cleaner if your boards are heavily soiled. Apply the solution section by section to stop it from drying out.
Avoid bleach or acidic cleaners, these can cause discolouration or strip the protective finish.
Step 5 – Scrub gently
Using a soft-bristle brush, scrub along the length of each board, following the grain. Gentle pressure is enough to lift grime and stains, scrubbing too hard won’t clean faster but can damage the surface. For stubborn spots, go over them twice rather than pressing harder.
Step 6 – Rinse again
Once you’ve worked the solution into the boards, rinse it away thoroughly. Leftover soap can leave streaks or attract more dirt, undoing your efforts. A clean water rinse ensures your decking dries evenly and looks fresh.
Step 7 – Leave to dry
Allow your deck to air dry naturally, sunlight and fresh air will do the job. If you want to speed things up, use a microfibre cloth or mop to soak up excess water. Avoid replacing furniture until the boards are completely dry to prevent marks or trapped moisture.
Pro tip – Call in the experts when you need to:
Even with the best DIY routine, some jobs can feel overwhelming, stubborn stains, tricky corners or simply not having the time. That’s where our team at Bristol Blast Away steps in.
We specialise in composite decking cleaning across Bristol, using the right balance of eco-friendly products and professional equipment to bring your boards back to life.
Think of it as the eighth step in your cleaning routine: when you want guaranteed results without the effort, let us handle the hard work while you sit back and enjoy your outdoor space.
Dealing with Specific Issues
Even with regular cleaning, your composite decking can face the occasional challenge. From green patches of moss to greasy barbecue spills, each problem needs a slightly different approach. Here’s how to handle the most common ones safely and effectively:
Moss & Algae
These are the usual suspects in shaded or damp areas, leaving your decking slippery and unsightly. A simple DIY solution works wonders: mix two parts water with one part white vinegar, apply it to the affected spots and leave it for about 20 minutes.
Then sprinkle bicarbonate of soda, scrub gently with a soft-bristle brush, and rinse clean. The result? A fresh, safe surface without harsh chemicals.
Grease & Oil Stains
Dropped a burger or spilled some cooking oil? Don’t panic, just act fast. Blot the area with a cloth (never rub, as it spreads the stain), then wash with hot soapy water. Quick action prevents the grease from soaking in and keeps your boards spotless.
Snow & Ice
Winter can be tough on decking. Always use a plastic shovel (metal edges can scratch or gouge the boards) to clear snow. Avoid rock salt or traditional de-icers, as they can be corrosive. Instead, choose pet-safe, non-corrosive alternatives that melt ice without damaging your decking and keep the whole family safe from slips.
Seasonal Decking Care Checklist
Your composite decking is built to handle every season, but with a little care at the right time, it will stay safe, spotless, and inviting all year round. Think of it as a four-season routine:
Spring: The reset
After months of rain and frost, give your deck a full clean. Rinse away dirt, scrub gently to remove moss or algae and let the boards breathe fresh again, ready for longer, brighter days.
Summer: Light & easy
This is when your decking works hardest, hosting barbecues, family dinners, and lazy afternoons. A quick sweep every few days and the occasional rinse after cooking will keep stains and grease at bay.
Autumn: The deep prep
Fallen leaves may look pretty, but left too long they trap moisture and encourage rot. Clear them away regularly, then do a deep clean before the cold sets in. It’s the best way to protect your boards through winter.
Winter: Safety first
Snow and ice can make decking slippery. Clear it with a plastic shovel, never metal and avoid harsh chemicals. If needed, use pet-safe, non-corrosive de-icers to keep the surface safe without harming the boards.
Follow this simple seasonal plan and your composite decking will stay strong, beautiful and ready for every moment outdoor, no matter the weather.
The best way to clean composite decking is to follow a routine that combines simple sweeping, gentle washing, and seasonal deep cleaning.
In other words, if you’ve ever asked yourself “how do you clean composite decking?”, the answer is to stick to safe methods that protect the surface while keeping it fresh year-round.
FAQs About Composite Decking Cleaning
We know you probably have lots of questions when it comes to looking after your composite decking. That’s why our team of experts at Bristol Blast Away have put together answers to the most common queries we hear from homeowners.
1. Can I pressure wash composite decking?
Yes, but only on a low setting (up to 1,500 PSI / ~100 bar) with a fan nozzle and always keep the lance at least 20cm from the surface to avoid damage.
2. What’s the best homemade composite decking cleaner?
Warm water with a dash of mild washing-up liquid works perfectly for regular cleaning. For algae or moss, a mix of water and white vinegar with a sprinkle of bicarbonate of soda is safe and effective.
3. Will cleaning affect the colour of my decking?
Not if you stick to the right products. Avoid bleach and acidic cleaners, which can strip the finish. Mild soaps and specialist decking cleaners will keep the colour looking fresh.
4. How do I remove stubborn algae or moss?
Apply a water-and-vinegar solution, let it sit for 20 minutes, then sprinkle bicarbonate of soda. Gently scrub with a soft-bristle brush and rinse well, no need for harsh chemicals.
5. Is cleaning composite decking safe for pets and plants?
Yes, as long as you avoid chemical-heavy products. Eco-friendly solutions and mild soaps are perfectly safe, just rinse thoroughly so no residue is left behind
Still have questions we haven’t covered? Our team at Bristol Blast Away is here to help. Get in touch with us today and we’ll be happy to give you tailored advice or even take care of the cleaning for you.
