Timber & Wood Cleaning

Timber is the surface where a pressure washer does the most obvious harm the fastest. Wood is made of fibres of varying density — the soft spring growth erodes far quicker than the hard summer growth — so a jet lance cuts the soft bands away and leaves a ridged, corduroy surface with the grain standing proud.

That surface then holds water, splinters, weathers faster and never returns to smooth. It's a permanent change to the timber, and on a bench or a piece of play equipment it turns a cosmetic problem into a safety one.

So timber gets the lightest touch we have: low pressure, controlled water, mechanical agitation with a brush rather than force, and a lot of patience.

Deciding what "clean" means first

Before any timber job we ask what finish the client actually wants, because there's a genuine choice here that doesn't exist on brick or concrete.

Timber silvers as it weathers. On cedar, larch and thermally modified cladding that silvering is usually intentional — it's the designed appearance and it protects the wood beneath. Cleaning back to fresh colour removes it, and the result is patchy unless every elevation is done identically, since south-facing timber silvers faster than north.

Removing organic growth is different from removing the patina. Green algae on a bench is dirt; silvering on cladding above it is age. We can take the first without attacking the second, but only if we've agreed which is which. Getting this wrong is the most common cause of disappointment on timber work, and it's entirely avoidable with a conversation and a test panel.

Play equipment and benches

Most of our timber work is on play areas and street furniture, and there the priorities are different again — it's about safety and usability more than appearance.

Green algae on a timber bench, boardwalk or trim trail is slippery when wet, and on equipment children climb on that matters. Timber play equipment is also usually pressure-treated softwood, which is soft to begin with; jetting it raises splinters directly onto surfaces that small hands grip.

We clean these with hot water at low pressure and brush agitation — no chemistry at all where we can avoid it, since these are surfaces children are in constant contact with. Where growth is heavy we'll propose a biocide, agree the product and the re-entry period with the site in writing, and apply it after the clean.

We also report what we find. Timber equipment fails from the inside and at ground contact, so while we're cleaning we'll photograph soft spots, splitting, loose fixings and rot at the base. That's often more valuable to a school or a parks team than the clean itself.

Graffiti on timber

This is a hard one, and it's worth being straight about it. Timber is porous and fibrous, so aerosol soaks in along the grain, travelling further in the soft bands than the hard ones. That produces a stain that follows the grain pattern and is very difficult to remove evenly.

The techniques that would remove it — sanding, aggressive chemicals, blasting — all take material off the surface, which on timber means changing its texture and colour permanently. You end up trading a tag for a bright, sanded patch with raised grain, which on a weathered fence or bench is arguably worse.

Realistically the options are usually: accept a faded shadow after gentle treatment, or clean and then re-stain or repaint the affected section so it's uniform. On painted or stained timber that's straightforward. On natural weathered timber, matching a new section to twenty years of silvering isn't possible, so sometimes the best advice is to treat the graffiti lightly and let it weather — which we'll say, even though it isn't a job for us.

After cleaning

Timber is the surface where aftercare makes the most difference. Once it's clean and dry, a treatment — an oil, a stain or a preservative appropriate to the timber — slows the return of organic growth and protects the fibres. Untreated timber that's been cleaned and left will be green again within a season or two in the North West.

Timing matters: the wood needs to be properly dry before anything is applied, which realistically means a few dry days after cleaning rather than the same afternoon. We'll flag when a site needs that gap so the programme allows for it rather than treating damp timber and having the finish fail.