Quick answer
Professional decking cleaning in Kent typically costs between £120 and £500 depending on the size and condition of the deck, with most Kent homeowners paying around £4 to £7 per square metre and a minimum charge of roughly £120 to £150 for small jobs. Softwood decking should be cleaned once a year, usually in late spring or early autumn, and it should never be blasted with a high-pressure lance. Softwood tolerates only around 500 to 1,200 PSI, and going higher tears the timber fibres, leaving a rough, splintered surface that traps water and goes green faster than before. The safest professional approach is a low-pressure or soft wash using an oxygen-based (sodium percarbonate) cleaner, worked along the grain, followed by a controlled rinse.
How much does decking cleaning cost in Kent?
Decking is priced by area and by condition. A newish deck with a light green film costs far less to restore than a fifteen year old softwood deck buried under moss with algae in every board gap.
Across the UK, professional deck cleaning runs at roughly £3 to £6 per square metre with an average around £4.50, according to Housekeep's 2026 cost guide. Kent and the wider South East sit at the higher end of national labour rates, so budget nearer the top of that band.
| Deck size | Typical area | Kent price range (clean only) | Notes |
|---|---|---|---|
| Small | Up to 10 m² | £120 to £180 | Usually a minimum charge job |
| Medium | 10 to 20 m² | £180 to £320 | The most common domestic size |
| Large | 20 to 40 m² | £320 to £500 | Often priced per m² rather than flat rate |
| Extra large | 40 m²+ | From £500 | Quoted per m², multi-level decks cost more |
| Clean plus oil or stain | Any size | Roughly double the clean-only price | Materials and a second visit are involved |
Prices above are typical market ranges for Kent in 2026 and are a guide, not a fixed quotation. Every deck is different, which is why we give a free, no-obligation quote before any work starts.
What pushes the price up or down?
- Condition. A deck with thick moss growth and blackened boards needs a pre-treatment soak and a second pass. Expect a 20 to 40 percent uplift over a routine maintenance clean.
- Access. Raised decks, steps, balustrades and decks behind narrow side gates all take longer.
- Material. Composite usually cleans faster than weathered softwood, but hardwood and grooved boards need more careful, slower work.
- Extras. Balustrade and spindle cleaning, joist inspection, board repairs, and oiling or staining are separate line items.
- Season. Demand peaks in spring and early summer across Kent. Booking in autumn or winter often means better availability and, at some firms, better rates.
If you are pricing up several outdoor surfaces at once, it is almost always cheaper to combine them. Many of our customers book decking alongside patio cleaning or a driveway clean in the same visit. Our guide to driveway cleaning costs in Kent breaks down that side of the pricing in the same detail.
Can you pressure wash decking, or will it ruin it?
You can, but the pressure setting matters more than almost anything else, and this is where most DIY decking jobs go wrong.
Timber is soft. A domestic pressure washer straight out of the box often runs at 1,800 to 2,200 PSI, and many machines top 3,000 PSI. Point that at a softwood deck and the water does not just remove algae, it removes wood. The surface fibres lift, the grain scars, and you are left with a furry, splintery finish that soaks up rainwater and greens over faster than it did before. It also stops oils and stains bonding properly, so the deck becomes harder to protect.
| Decking material | Safe working pressure | Nozzle and distance | Key risk if you get it wrong |
|---|---|---|---|
| Softwood (pine, spruce) | 500 to 1,200 PSI | 40 degree fan, 30 cm away | Fibre lifting, permanent grain scarring, splinters |
| Hardwood (oak, teak, ipe, balau) | Up to around 1,500 PSI | 40 degree fan, 30 cm away | Surface roughening, colour patchiness |
| Composite (Trex, Millboard and similar) | Manufacturer dependent, often capped well below 1,500 PSI on older boards | Fan tip, minimum 20 cm away | Warranty invalidation, surface damage to the cap layer |
Three rules apply whatever the material:
- Work along the grain, never across it. Cross-grain passes are what create that rough, hairy finish.
- Keep the lance moving and keep the distance constant. Pausing in one spot for even a second or two etches a line into the board.
- Test a hidden area first, ideally a board under a planter or at the far corner, before doing the whole deck.
For anyone who has read our guide on soft washing versus pressure washing a roof, the principle here is identical. The chemistry should do the work, and the water should only rinse.
Which decking cleaning method is right for your deck?
There are three broad approaches, and professionals often blend them.
| Method | How it works | Best for | Watch out for |
|---|---|---|---|
| Soft wash / low pressure | An oxygen-based or biocidal cleaner is applied, dwells, then is rinsed at low pressure | Almost all softwood and composite decks, especially older ones | Needs the right dwell time, too short and the algae stays |
| Controlled pressure washing | Fan-tip lance at a capped pressure, worked board by board along the grain | Hardwood, heavily soiled decks, ingrained grime in board grooves | Very easy to overdo, the main cause of DIY damage |
| Manual scrub and treat | Cleaner applied and worked in with a stiff deck brush, then rinsed | Small decks, delicate or antique timber, decks near ponds | Slow, hard work, and rarely reaches deep-set staining |
Why professionals favour oxygen-based cleaners
Sodium percarbonate, often sold as oxygen bleach, releases oxygen when mixed with water. That oxygen lifts dirt and organic growth out of the timber grain rather than stripping the surface off. Unlike chlorine bleach, it does not bleach the timber colour, does not corrode fixings, and is far kinder to the lawn, borders and pond life immediately around the deck. In Kent gardens, where decking is very often surrounded by planting, that matters.
Chlorine bleach can work in the short term, but it damages lignin in timber over time, can lighten composite surfaces permanently, and kills plants it runs off onto. It is not what we use.
Why does decking go green and slippery in Kent?
Kent's climate is close to perfect for algae. Mild, damp winters, a long shoulder season of wet weather, and plenty of shaded, north-facing gardens under mature trees. Algae needs only moisture, low light and a slightly rough surface to hold onto, and a timber deck offers all three.
The result is the green film almost every Kent deck develops by late autumn. It is not just cosmetic. Slippery decking is flagged by both RoSPA and the HSE as a genuine safety hazard, and slippery outdoor surfaces are linked to thousands of UK slip and fall accidents each year. A green deck is at its most dangerous in the first hour after light rain, when the algae layer becomes gel-like.
There is a structural cost too. Persistent algae and moss hold moisture against the timber, which accelerates rot at board ends, around fixings and in the joists below. Boards that have been left green for several seasons often have soft spots that only show up once the deck is cleaned. This is the same mechanism we describe in our guide to moss damage on roofs, just applied to horizontal timber instead of tiles.
How often should decking be cleaned?
| Situation | Recommended frequency |
|---|---|
| Softwood deck, open and sunny | Once a year |
| Softwood deck, shaded or under trees | Twice a year, spring and autumn |
| Hardwood deck | Once a year, with a light rinse mid-season |
| Composite deck | Once a year, plus spot cleaning as needed |
| Deck used for a hot tub or dining | Twice a year, plus prompt cleanup of spills |
The best time to clean decking in Kent is late spring or early autumn. Late spring gets the deck ready for the season and lets any oil or stain cure in warm, dry conditions. Early autumn strips off a summer of pollen, dust and organic debris before winter damp sets in, and it is usually the cheaper slot because demand has dropped away. Avoid deep midwinter, when timber stays wet for days and treatments will not cure.
Timber versus composite decking: what actually changes?
A common assumption is that composite decking does not need cleaning. It does, just differently.
Composite boards do not rot and do not need oiling, but the textured cap layer still traps pollen, dust and organic matter, and algae grows happily on that film. The difference is that the algae sits on the surface rather than in the grain, so it comes off more easily with the right cleaner and lower pressure.
The critical point with composite is the warranty. Trex, for example, states that pressure washing early-generation decking can void the warranty for any damage it causes, and that bleach-based or acidic products will lighten the surface. Manufacturer guidance varies significantly between brands and product generations, so a competent contractor should ask what boards you have before quoting. If they do not ask, that tells you something.
Timber decks have the opposite problem. They clean up beautifully but need protection afterwards, because cleaning opens the grain back up.
Should you oil or stain decking after cleaning?
For timber, yes, and the timing is important.
Cleaning removes the weathered grey surface layer and any old degraded finish, which leaves fresh timber exposed. Left bare, it will grey off again within a season. Applying a decking oil or stain seals the grain, slows UV greying, and makes the next clean much easier.
The sequence that works:
- Clean the deck thoroughly and let it dry.
- Wait two to three dry days so the moisture content drops. Applying oil to damp timber traps water and causes patchy, blotchy results.
- Check the forecast for at least 24 to 48 hours of dry weather after application.
- Apply thin, even coats along the grain, and wipe off any excess that has not soaked in.
Because Kent weather rarely hands you a guaranteed dry week, most professional jobs are booked as two visits: clean, then return to treat. Composite decking does not need oiling and should not be oiled.
DIY or hire a professional decking cleaner?
DIY makes sense for a small, newer deck with light surface algae. A stiff brush, a sodium percarbonate cleaner and an afternoon will handle it.
Call in a professional when:
- The deck is 20 m² or larger, where hand scrubbing becomes genuinely punishing work
- Boards are blackened or heavily mossed, which needs pre-treatment and controlled equipment
- The deck is raised, multi-level or has balustrades, where working at height and awkward angles come into play
- It is composite under warranty, where the wrong method has a financial consequence
- You want the deck cleaned and treated as a single managed job
- You suspect rot or loose fixings and want the substructure looked at while the surface is exposed
A professional clean also gives you a proper inspection. We routinely find soft board ends, corroded fixings and joist damage that were completely hidden under moss.
How to choose a decking cleaning company in Kent
Ask any contractor these five questions before you book:
- What pressure will you use on my boards, and why? A confident, specific answer is a good sign. Vagueness is not.
- What cleaning products do you use, and are they safe for my planting? Oxygen-based cleaners should be the default.
- Are you fully insured? Ask to see the certificate.
- Is the quote fixed or per square metre, and what is included? Balustrades, steps and treatment are often extra.
- Do you know my decking brand's cleaning guidance? Essential for composite.
M&T Elite Cleaning is a family-run business with over five years of experience, fully insured, and rated 4.9 stars from over 50 local reviews. We cover Kent, Medway and the wider South East, including Rochester, Chatham, Strood, Maidstone, Sevenoaks, Ashford, Canterbury, Tonbridge and Tunbridge Wells.
Get your decking back before the season ends
If your deck has gone green, slippery or grey, late summer and early autumn is the ideal window to put it right, and to get it sealed before the winter damp arrives.
Get a free, no-obligation decking cleaning quote or call us on 07862712401. You can also message us on WhatsApp with a photo of your deck for a faster estimate.
Booking more than one surface? Ask about combining decking with patio cleaning or driveway cleaning in the same visit.
Frequently asked questions
How much does it cost to clean decking in Kent? Most Kent homeowners pay between £120 and £500. Small decks up to 10 m² typically cost £120 to £180, medium decks of 10 to 20 m² cost £180 to £320, and large decks of 20 to 40 m² cost £320 to £500. Adding an oil or stain treatment roughly doubles the price.
Can I pressure wash my decking? Yes, but only at low pressure. Softwood should not exceed roughly 500 to 1,200 PSI, hardwood around 1,500 PSI, and composite should follow manufacturer guidance, which is often lower still. Always use a 40 degree fan nozzle, stay about 30 cm back, and work along the grain, never across it.
How do I remove green algae from decking? Apply an oxygen-based cleaner containing sodium percarbonate, let it dwell for around 20 minutes so it lifts the growth, agitate with a stiff deck brush, then rinse at low pressure. Avoid chlorine bleach, which damages timber over time and harms surrounding planting.
How often should decking be cleaned? Once a year for most decks. Twice a year if the deck is shaded, sits under trees, or takes heavy use such as a hot tub or outdoor dining.
When is the best time of year to clean decking in Kent? Late spring or early autumn. Both give reliable enough weather for treatments to cure, and autumn is usually cheaper because demand has dropped after the summer peak.
Does composite decking need cleaning? Yes. Composite will not rot, but its textured surface still traps pollen and organic matter that algae feeds on. It needs an annual clean, using a method that complies with the manufacturer's guidance so the warranty stays intact.
Should I oil my decking after cleaning? Timber decking, yes. Wait two to three dry days after cleaning so the moisture content drops, then apply thin coats along the grain with at least 24 to 48 hours of dry weather ahead. Composite decking should not be oiled.
Will cleaning fix a slippery deck? Cleaning removes the algae layer that causes the slipperiness, so yes, immediately. To keep it that way, seal the timber after cleaning and clear leaf debris regularly, especially in autumn.
