How Do You Clean a Fence That Has Gone Green?
The green film on a fence is algae, and algae has roots in the surface. Pressure alone knocks off the visible layer and leaves the roots behind, so it returns within a season. A low-pressure treatment that kills the growth at the root, then a gentle rinse, is what keeps a fence clean for years.
Why is one side of my fence green and the other clean?
Because algae grows where the sun does not reach. The shaded face of a fence — usually the north side, or whichever side backs onto trees — stays damp for hours longer after every rain, and that is all the growth needs. A fence with a bright clean south face and a solid green north face is not dirty on one side; it is biologically colonized on one side.
In the Shoals this is close to universal on privacy fences. Humidity off the river, heavy tree cover in the older neighborhoods, and a long warm season mean the shaded face of a wood or vinyl fence will go green reliably every year or two without intervention.
Does the material change how a fence should be cleaned?
| Fence type | Right method | Why |
|---|---|---|
| Vinyl / PVC | Soft wash | Pressure marks and can crack cold vinyl |
| Wood (privacy, picket) | Soft wash + low rinse | Full pressure tears the grain |
| Aluminum / wrought iron | Soft wash | Pressure chips powder coat and paint |
| Chain link | Low pressure | Little to damage, but rinse the whole mesh |
| Brick or masonry columns | Soft wash | Pressure erodes mortar joints |
Will cleaning kill the plants growing along the fence?
Not if the work is done properly, and this is a fair thing to ask about before anyone starts. The landscaping along a fence line is usually the customer's, planted deliberately, and it sits directly in the runoff path. Pre-wetting the beds, tarping where it matters, and rinsing thoroughly afterward is standard practice, not an upsell.
The failure mode is a solution left to dry on foliage in the sun. That is what burns shrubs, and it is entirely avoidable with the right sequence. Ask anyone quoting the job how they handle the plants — the answer tells you a lot about whether they have done many fences.
Is it worth cleaning a fence or should I just replace it?
Clean it first, then decide. A fence that looks finished is very often a sound fence under a layer of algae, and the difference between the two is a few hundred dollars against a few thousand. The honest test is structural: if the posts are solid and the boards are not rotted through, the fence has years left and only looks otherwise.
Fence cleaning is priced under pressure washing, from $299, by linear footage and condition. Where it genuinely is not worth it — punky posts, boards you can push a thumb through — we will tell you that rather than take the job, because a cleaned rotten fence is still a rotten fence.
Questions we hear about this
How much does it cost to clean a fence?
Fence cleaning falls under pressure washing, which starts from $299 and is quoted by linear footage, height, and how much growth is on it. A free walk-round gives you a real number for your fence in writing.
Why did my fence go green again a few months after cleaning?
Almost always because it was pressure-only. Force removes the algae you can see and leaves the roots in the surface, so the growth re-establishes fast — usually within a season here. A treatment that kills it at the root is what buys you years instead of months.
Can you clean a fence without damaging my neighbour’s side?
Yes, and it is worth deciding up front which sides you want done. We can clean one face or both, and if the far side is on a neighbour’s property we will want their okay before we set foot over there. Most people book both faces at once, since half a clean fence looks odd from the street.
Should I stain the fence after cleaning?
If it is bare wood and you want it to stay looking new, yes — but let it dry properly first. In Shoals humidity that usually means a couple of clear days. Staining over damp wood traps moisture in the boards and the finish fails early.