Fence Cleaning

A fence takes more abuse than any other wood on the property. It has no roof over it, it gets sun on one face and shade on the other, and the bottom rail sits close enough to the ground that every rainstorm splashes soil back onto it. That is why the side you never look at is almost always the dirty one.

Wood goes gray from UV oxidation, and that gray is a thin dead layer sitting on top of sound wood. High pressure does strip it, but it strips it by tearing up the fibers underneath, and a furred board holds dirt worse than it did before. We use a sodium percarbonate brightener at low pressure instead. The chemistry lifts the gray, the water only rinses, and the grain stays closed.

Pressure-treated pine is the most common fence out here and the most dramatic to clean, because the green tint and the gray layer both come off and the wood underneath is still bright. Cedar needs a gentler mix. It carries natural oils that give it rot resistance, and a harsh cleaner takes those off along with the dirt.

Vinyl is the opposite problem. The green film on a vinyl panel is algae, not staining, and it comes off with a soft wash detergent at garden hose pressure. What you avoid is forcing water into the seams and behind the post caps, which is exactly what happens when someone puts a wand on it. Composite gets a composite-safe cleaner, because the wrong one hazes the cap layer and that does not come back.

Two local things drive most of the fence work we do. Post-and-rail and painted board fence is everywhere around Pomfret and Woodstock, and paddock fence greens up on the shaded runs faster than anything else because the grass grows right up against it and never lets it dry. And any fence along a road picks up sand and salt spray all winter, which shows in spring as a gray band across the bottom third of the traffic side.