If you know the frustration of watching your once beautiful new deck turn dirty and green overtime – marked by the mould, moss and algae which inevitably forms in our damp British weather – then it’s time to invest in a good decking cleaner.
A grimy deck can not only be an eyesore in your garden, causing you to put off organising that summer BBQ, but it can also be a health and safety hazard. Moss and algae are slippery, especially when wet, and it’s all too easy to end up with a red face and a bruised behind – or worse.
So, to restore your decking to its former glory – and make it once more safe to walk on – you need the aforementioned decking cleaner. These powerful cleaning products are purposely designed to quickly remove dirt, mould and algae from your decking. You simply spray them on, scrub if required, and rinse them off (or in some cases, just leave them to work their magic).
Last update on 2021-09-23 / All Pricing & Imagery from Amazon Product Advertising API
With so many options on the market, we know it can be hard to select just one, so we’ve put together this guide featuring what we think are the five best decking cleaners. We’ve graded them based on how effective they are, how much decking they clean, whether you can use them on other surfaces too, and which one offers the best value for money.
Our best decking cleaner – and for an affordable price too
We all know Ronseal’s tagline is ‘does exactly what it says on the tin’ – and this powerful decking cleaner is no exception.
Those claims on the tin include its fast-acting revival of weathered decking, and that it removes moss, mould and algae – all of which are undeniably true. You simply scrub this cleaner on, leave it for 15-20 minutes, rinse off with a pressure washer and voila! A gleaming, moss-free deck restored to its natural appearance.
The pack contains 5 litres, which is a good size compared to similar cleaners and is enough to treat up to 24 square metres of decking. This means that for smaller decks, you should have enough for more than one application.
Many happy customers describe how this ‘miracle’ product transformed their green and moss-covered decking, making it look as good as new. There is the odd review that claims it didn’t work for them, but these are by far the exception, not the rule.
Overall, this is one of the best, most powerful decking cleaners on the market – not to mention one of the most reasonably priced.
- Strong cleaning power – removes stains, moss and mould from timber.
- Fast-acting – works in less than 20 minutes.
- Ideal for prepping a deck prior to oiling or staining – it opens pores in the wood to encourage adhesion.
- 5-litre pack size will clean an area of up to 24 square metres.
- Suitable for all types of decking.
- Strong chemical smell.
- Not eco-friendly – do not allow undiluted product near water sources.
- Requires a lot of elbow grease!
Can be diluted, allowing you to clean more deck for your money
Another great value option for sprucing up your decking is this Cuprinol Deck Cleaner.
You can use this water-based formula to remove dirt, grease, green algae and mould from your deck. Simply brush or spray it on, scrub the most affected areas, leave to develop for a few minutes, and rinse with water. It’s also suitable for use on patios and stonework.
The pack contains 2.5 litres, and 1 litre of the product will clean 7 – 15 square metres of decking, depending on its condition. However, if your decking is only experiencing light algae growth, you can dilute the cleaner with water before application. The results will be just as effective, but the product will last longer.
As with the Ronseal cleaner, this can also be used to prep your deck for oiling or staining. Allow the decking to dry fully before applying any treatment – this should take around 16 hours, depending on your weather conditions.
Reviewers are predominantly happy with this product, as both a cleaner (especially for removing slippery algae), and as a pre-treatment for oiling. There are those who weren’t so successful, but it is possible they didn’t scrub the surface enough – this cleaner is impressive, but it won’t do much on its own.
- Multi-purpose cleaner, also suitable for use on stonework.
- Effectively prepares your decking for finishing treatments.
- Sterilises your deck’s surface to discourage regrowth of algae and mould.
- Can be diluted to make it last longer.
- Must be applied evenly to avoid uneven colouration.
- Not suitable for use in wet weather conditions.
- Needs a lot of scrubbing to remove thick dirt and algae.
A solid choice for a shiny deck, or other woodwork
This Rustins Decking Cleaner is perfect for cleaning not only decking but fences, cladding and window sills too.
Rustins recommend applying the product to your decking with a sprayer, watering can or brush, then leaving it to develop for 10 minutes, before scrubbing with a stiff brush. It should then be left for a further 30 minutes, before being rinsed with a pressure-washer or garden hose.
The 4-litre container gives you plenty of product to work with and is sufficient to remove dirt, algae and mildew from 20 – 25 square metres of decking. It will work as a pre-treatment before oiling, but you’ll need to allow at least 24 hours for your deck to dry first.
It does have a slightly longer development time than the previous two products, and the guidelines also mention repeating the process until the decking is clean, suggesting it’s not quite as powerful as the Ronseal or Cuprinol cleaners. This is corroborated by multiple users, who have mentioned needing more than one bottle.
On the whole, though, we are happy with its effectiveness, and this is another great decking cleaner for the money – especially if you have other exterior woodwork that needs attention.
- Designed for use on old and new decks.
- 4-litre pack size will clean up to 25 square metres of decking.
- Also recommended for use on fences and other exterior woodwork.
- Longer development time of 40 minutes – double previous options.
- 24 hour drying time before treatments can be applied.
If you can wait a few days for results, this is the easiest product to use
‘Simply spray & walk away’ is the tagline for this Pro-Kleen Algae Remover – and that’s exactly what you can do.
Unlike the three previous cleaners, this Pro-Kleen formula does not need you to scrub it into your decking with a lot of elbow grease, hang around for half an hour, and then pressure wash it off. Instead, you just spray it on the affected area and leave it to work. Within 2-3 days, you’ll begin to notice results, as the algae and moss start to die away (you may still need to sweep the decking to remove dead moss).
You get 5 litres of product per pack, but it’s recommended to dilute it at 1 part cleaner, 4 parts water. This makes a total of 25 litres of cleaning fluid, which is capable of treating up to 200 square metres of decking. Best of all, it helps to prevent the regrowth of algae for up to 6 months.
It’s not limited to decking either – like the Cuprinol cleaner, you can use it on patios and stonework, as well as driveways, sheds, fencing, outdoor furniture and PVC windows. In fact, pretty much any exterior surface that’s capable of growing mould and algae can benefit from a spray!
This product is definitely high quality and it delivers on its promises. The results aren’t instantaneous, but if you don’t mind waiting, this has got to be one of the easiest ways to eradicate moss and algae from your decking.
- Easy to use – simply spray and leave to work.
- 5 litres can be diluted to make an impressive 25 litres of cleaning solution.
- Multi-purpose – also safe for use on a variety of exterior surfaces, including driveways, patios, fences and PVC windows.
- Helps to prevent the re-growth of algae for up to 6 months.
- Biodegradable, non-acidic formula – better for the environment than some other cleaners.
- Takes a few days to work.
- Needs to be used in dry weather – results can be ruined by rain.
More expensive, but stretches further than others
This 4-in-1 Jeyes Power Cleaner is designed to clean decking, remove algae, prevent regrowth and eliminate germs.
This is another cleaner that should be diluted for best results; the 4 litres of cleaner in the container can treat up to 198 square metres of decking when mixed with water as per the instructions. The disinfectant formula contains pesticides and claims to remove 99.9% of germs from surfaces.
To apply, you saturate the surface of the decking with the product, leave it to dry, and then rinse with water. This makes it not the quickest or easiest product to use, but it is effective. As well as decking, this multi-purpose cleaner also removes dirt and algae from patios, brick surfaces and drains.
This is, however, the priciest product on our list, which might be enough for it to lose out against its competitors – although it does clean a much larger surface area than some, and it is multi-purpose – so you could consider it better value for money overall.
- Cleans up to 198 square metres of decking, restoring its natural colour.
- Also works on paths, patios and brick surfaces.
- Foam lifting action prevents the regrowth of algae.
- Kills 99.9% of germs.
- Can be used prior to oiling or varnishing.
- More expensive than competitors.
- May require more than one application, depending on the thickness of algae.
How To Clean Your Garden Decking Surface
Exactly how to apply and remove your decking cleaner will depend on which product you purchase, so you should always follow the manufacturer’s instructions. Some require lots of scrubbing; others can simply be sprayed on and left to do their thing. As an example, to use our top pick, the Ronseal Decking Cleaner, to clean your garden decking surface, you should take the following steps:
First, make sure you’re prepared. Many decking cleaners contain strong chemicals and pesticides, which can cause serious irritation if they come into contact with your skin or eyes. You should wear old clothing and protective gloves when using decking cleaner.
Before applying the cleaner, clear your decking, removing any furniture or plants, and sweep to remove loose debris. You may also wish to protect any surrounding plants, lawns or furniture with dust sheets. If they do come into contact with any undiluted product, rinse them immediately. Choose a dry day, when no rain is forecast, and be careful not to allow any undiluted product into drains or waterways.
Once your deck is cleared and ready, pour the cleaner directly onto your decking, using a stiff brush to scrub it into the surface. Focus particularly on the worst affected areas. Leave it to develop for 15-20 minutes (remember this is specific to Ronseal, development times vary between brands).
After 20 minutes, remove the cleaner using either water and a stiff brush to scrub it off, or a pressure washer (this is the easiest option if you have one). Work methodically, from one end of the decking to the other, until all the product and grime is washed away.
Stand back and admire your shiny new, algae-free deck!