Decking and Fence Cleaning Cardiff

What Cardiff Winters Do To Timber

Decks here spend half the year damp. Cardiff takes more rain than most UK cities, and a garden deck in Roath or Penylan that sits in the shade of a fence, a shed or next door's conifers barely sees direct sun between November and March. Algae colonises the grain and holds water against the boards. Green film, black spotting and a soft slimy surface at the shaded end are the same problem at three different stages.

The slip risk is the part people underestimate. Wet algae on a smooth-faced deck board has roughly the grip of ice, and steps are the worst of it because the tread is short and you are usually carrying something. If you can draw a clean line through the surface with your shoe, the deck is overdue. Grooved boards are no safer than smooth ones, whatever they were sold as: the grooves hold water, growth and grit long after the rest of the board has dried.

Why Too Much Pressure Furs the Grain

Softwood is soft, and a lance held too close does permanent damage in under a second. A narrow jet at full pressure tears out the softer growth between the harder grain lines and leaves the surface fibrous. That is furring, and no amount of washing brings it back. The board turns rough underfoot, splinters lift, and the opened grain holds far more water than it did before, so the deck goes green again faster than it used to.

It shows from the house as well. Held at an angle or moved unevenly, a jet leaves tiger stripes across the boards that only sanding will remove. On pressure-treated softwood the preservative is concentrated in the outer few millimetres, so blasting that layer off takes the rot protection with it. We work the other way round. An oxygen based deck cleaner goes on first and is left to dwell so the algae releases on its own, then a wide fan nozzle at low pressure is swept along the grain at a fixed distance. Strong hypochlorite stays off bare timber, because it bleaches the wood pale and roughens the fibres.

Timber and Composite Decking Are Not Cleaned the Same Way

Most Cardiff back gardens have pressure-treated softwood decking, usually European redwood, and it is the least forgiving surface of the lot: absorbent, easily marked, and with the preservative only skin deep. Hardwood decks in balau or ipe are far tougher underfoot, but they weather to a silver grey that sits in the surface fibres, so washing alone will not bring the colour back without an oxalic acid brightener afterwards. We tell you which you have before we quote, because it decides how the finished deck will look, not just how clean it gets.

Composite is not maintenance free, whatever the brochure said. Uncapped boards are wood flour and plastic, and mould grows happily in the embossed grain. Capped boards resist that, but the cap scars, and once a pressure mark is in it, it stays. Manufacturers publish a maximum pressure and a minimum nozzle distance for a reason, and we stay inside both, using a soft brush, a composite safe cleaner and a low pressure rinse. No wire brushes and no rotary flat surface heads on a capped board.

Decking Cleaning in Cardiff, Step by Step

1. Walk the deck first. We check the boards before anything gets wet. Loose fixings, proud screws, soft joist ends and anything already rotted get flagged to you, because a lance will find them the hard way.
2. Clear and protect. Furniture, pots and the barbecue come off the deck. Borders and lawn at the edges are watered then sheeted, and deck lights, outside sockets and any exposed cable are covered.
3. Treat the growth. A cleaner suited to the surface is applied and left to work. On shaded timber this stage does most of the job, and it is why the wash itself can be done at a pressure the boards survive.
4. Wash with the grain. Wide fan nozzle, consistent distance, steady sweeps along the length of each board rather than across it. Steps, handrails and spindles are done by hand where an even sweep is impossible.
5. Rinse everything down. The deck, the fence behind it, the surrounding paving and any glass are rinsed before residue can dry on, and the dirty water is directed away from ponds and borders.
6. Leave it to dry. We tell you how long the timber needs before it can be oiled or stained, based on that week's forecast and how wet the boards were when we finished.

Decking & Fence Cleaning expertise across Cardiff and South Wales

A fence takes the same weather as the deck, from both sides, with no foot traffic to wear the growth back. The panels that go worst are the ones with a hedge or a shrub border pushed up against them, where the timber never dries and the bottom 300mm of every board stays wet from October to March. You get green algae on the faces, black mould in the grain and orange lichen along the cap. Cleaning it off is not only cosmetic. Growth keeps moisture in the timber, and wet softwood in permanent contact with soil and planting is what rots feather-edge boards and gravel board tops out years early.

A fence panel is thinner than anything on your deck. Lap and feather-edge boards are only a few millimetres thick and they flex, so a jet a paving slab would shrug off punches straight through or lifts the panel out of its frame. Fence work is mostly treatment and rinse with the pressure right down. Concrete posts and gravel boards will take more. Timber posts often will not, and we test the base of each one before we start, because a rotten post is usually being held up by the panels either side of it.

• Deck boards, steps, handrails, spindles and fascia trim
• Softwood, hardwood, capped and uncapped composite and PVC boards
• Lap, feather-edge and closeboard fence panels
• Timber and concrete posts, gravel boards and post caps
• Trellis, arbours, pergolas, gates and sleeper edging
• Garden steps, paths, patio edges and garden furniture cleaned on the same visit

We clean your side. The far side of a boundary fence belongs to a conversation with your neighbour rather than to us, so if you want both faces done we need them to agree first. Even on a one sided job we keep overspray down, and it is worth giving next door a knock so washing comes off the line and cushions come indoors.

Oiling or Staining After the Clean

Cleaning opens the timber up, which is what a finish wants and exactly why the next bit cannot be rushed. Oil applied to damp boards will not penetrate. It sits on the surface, dries patchy or milky and lifts within a season. Give the deck at least 48 hours of dry weather in summer, and longer in autumn, when boards here can hold moisture for most of a week. The test is simple: sprinkle water on a board, and if it soaks straight in the timber is ready.

There is a practical reason to clean before you refinish rather than after. Stain and oil bond to timber, not to the algae and grey surface dust sitting on top of it, so a finish rolled over a dirty deck lifts in sheets inside a year and then has to be stripped before anything else can happen. Cleaning also shows you what you actually have, since patchy old stain, split boards and soft spots only become obvious once the green is off. On softwood we would point you at a penetrating decking oil rather than a film-forming varnish, because film finishes on horizontal boards peel where the sun and the foot traffic hit them.

What changes the price of decking & fence cleaning

Most Cardiff decks are small, so this is one of the cheaper jobs we do. As indicative guidance, a straightforward 15 to 25 square metre softwood deck usually lands somewhere around £120 to £220, and fencing is normally priced by the panel or by the run rather than by area. Those are guide figures, not a quote. What moves the number is size and layout, how thick the growth is, whether old flaking stain has to come off, whether there are steps and balustrades, and how the garden is reached, because a terrace in Canton with no side access means every hose runs through the house.

Time on site follows the same logic. A single deck with surface algae is often 60 to 90 minutes of actual washing, plus setting up, dwell time and rinsing. Add a run of fence panels and you are into a half day. Failed stain that has to be stripped first is a different job, and we say so at the quote rather than on the day.

Ready when you are: arrange your decking & fence cleaning quote

We have been cleaning exteriors around Cardiff since 2019 and our Google rating is 5.0 from five reviews. Decking and fencing fits alongside the rest of the round, so gardens in Whitchurch, Rhiwbina, Llanishen, Lisvane, Cyncoed and Llandaff are normal territory, as are Barry, Newport and the wider South Wales area. Call or message 07576 128903, or email Liamdunn2406@outlook.com. We answer seven days a week, 7:00 to 21:30, and quotes are free. A couple of photos and rough measurements are usually enough for us to price the work without coming out first.