How to clean a fence and make it last longer

A clean fence makes the whole garden look sharper — but more importantly, it lasts longer. Dirt, algae, and green mould don't just sit on the surface; they hold moisture against the wood and speed up rot. Knowing how to clean a fence properly, and following up with the right treatment, can add years to its life. Here's exactly what to do.

Why fences go green so quickly

Most timber fencing in Lincolnshire is featheredge, closeboard, or panel — all of which have rough, porous surfaces that trap moisture. Add the shade from a hedge or a north-facing garden, and you've got near-perfect conditions for algae, green mould, and lichen to take hold.

This isn't just a cosmetic problem. Once green growth is established, it retains moisture against the wood grain. Over a season or two that leads to soft spots, splits, and eventually posts that snap at ground level — which is a much more expensive fix than an afternoon's cleaning.

What you'll need before you start

You don't need a lot of kit, but having the right things to hand makes the job far quicker.

• Stiff-bristled brush or scrubbing broom — for working cleaner into the grain
• Garden sprayer or pump sprayer — for applying treatment
• Biocidal fence cleaner or diluted bleach solution — kills algae at the root rather than just shifting it
• Pressure washer (optional but useful) — speeds up rinsing dramatically
• Eye protection and gloves — bleach-based products are harsh
• Drop cloth or plastic sheeting — to protect plants at the base of the fence

If you're using a pressure washer, keep the pressure moderate — around 1,200–1,500 PSI — and use a wide fan tip. Timber is softer than you think, and driving a jet lance straight into old wood at close range will raise the grain badly.

How to clean a fence step by step

1. Cover nearby plants. Fence cleaner and high-pressure rinse water will splash. A few minutes with a drop cloth saves you replanting later.
2. Apply your cleaner. Spray or brush on a diluted biocidal fence cleaner, working from the top of each panel down. Let it dwell for 10–15 minutes so it can penetrate and kill the algae rather than just loosening the surface layer.
3. Scrub. Work the cleaner into the wood with a stiff brush, paying attention to the overlapping edges of featheredge boards where moisture and growth collect most.
4. Rinse. Wash down with a hose or pressure washer, again working top to bottom. The water should run relatively clear — if it's still running dark green, apply cleaner again.
5. Let it dry. This is the step people rush, and it matters. Wood needs to be genuinely dry before you apply any preservative or stain — ideally two to three dry days, not just a few hours after a damp morning.
6. Treat or seal. Once dry, apply a quality timber preservative, fence paint, or stain. This seals the grain against the next bout of wet weather and is what makes the difference between cleaning lasting one season and lasting five.

Should you pressure wash a fence?

Done carefully, yes — a pressure washer cuts the work significantly. The key is distance and angle. Hold the lance at least 30 cm from the surface and work with the grain, not across it. Getting too close or using a narrow turbo nozzle will strip the surface fibres and leave the wood looking frayed.

For very old, weathered timber, a brush and a garden hose is sometimes the safer choice. If the wood already has soft sections, pressure washing can make them worse. Give each board a quick press with your thumb — if it feels spongy, treat it gently.

What about panel fencing?

Woven panel fences are trickier. The interlocking slats hold water between layers, and a pressure washer forced into the gaps can blow panels apart — especially older ones. Scrubbing by hand and rinsing with a moderate hose pressure tends to give a better result without risking structural damage.

How often should you clean a fence?

Once a year is a good rhythm for most Lincolnshire gardens — ideally in late spring when the wood has dried out after winter, or in early autumn before the damp sets in again. A fence that gets a proper clean and re-treatment every year or two will outlast one that's left to the elements by a significant margin.

In areas with heavy tree cover — like many gardens in Nettleham, Washingborough, or the older parts of Lincoln — annual cleaning may not be optional. Leaf debris against the base of panels causes the worst rot, so clearing that away and treating the bottom foot of each panel makes a real difference.

Signs your fence needs attention now

• Visible green or black algae across more than a third of the surface
• Dark staining along the horizontal rails where water sits
• Soft or spongy patches when you press the wood
• Flaking or peeling where old preservative is lifting off

If you're seeing any of those, it's worth acting sooner rather than later. Left another season, you may be looking at replacement rather than cleaning.

When it's worth calling a professional

If your fence runs along the full length of the garden, covers a large area, or adjoins a neighbour's boundary — getting it cleaned and treated properly without causing any disturbance takes time and a bit of experience. We cover fence and surface cleaning across Lincolnshire, from Cherry Willingham and Branston right across to the coast, and we carry the right kit to get it done in a fraction of the time it takes by hand.

You can see the full range of what we cover on our services page, and if you'd like advice on decking and timber more broadly, our decking and wood care guides go into more detail on treatments and maintenance.

We work across Lincolnshire — check the areas we cover to see if we're local to you.

If your fence is due a clean and you'd rather leave it to us, get a free quote today. We'll give you a straight answer on what's involved and what it'll cost.

Frequently asked questions

---

Need a hand with yours? We cover Lincolnshire for patios, driveways, paths and more — see the areas we cover or browse our services. Get a free quote or call 07874 010739.