How to Clean a Wood Fence

Co-authored by wikiHow Staff

Last Updated: November 5, 2022 References

A wood fence can collect all sorts of build-up outside. Mold, mildew, mud and algae can all become problems over time. You may be wondering how to clean a wood fence without harming your plants or the surface. Luckily, by taking steps to prepare the surrounding area, and using the right equipment and tools, you can have a spic-n-span wood fence in no time.

Part 1

Part 1 of 3:

Organizing Your Work Area

1
Cover the ground around the fence with plastic. If you have plants you care about or you decide to use a chemical cleaner, you’ll want to cover the area around the fence with plastic. Go to your local hardware store and purchase enough plastic sheeting to cover the plants and grass up to at least 3 feet (0.91 m) from your wood fence.^{[1]
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- Purchase just enough plastic for one section and move it with you when you move to the next to save money.
2
Remove heavy debris with a wire brush. A stainless steel wire brush prepares a wood fence for painting, but it is also handy at getting rid of stuck on dirt and grime. Run a wire brush over any caked-on or large pieces of debris. Be careful not to scrub a wire brush into a painted fence too deeply.
- If you don’t already have one, purchase a wire brush at a hardware or home improvement store.
- Substitute a plastic bristle scrub brush for a wire brush and use a little more pressure.
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3
Spray the fence down with a garden hose. Make sure you have a garden hose handy, whether or not you’re using the assistance of a power washer. Wet your wood fence down and remove surface dirt by spraying all over with a garden hose on medium to high pressure.^{[2]
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Part 2

Part 2 of 3:

Using a Power Washer

1
Use a lower powered washer. There’s no need to spray your wood fence with the most powerful washer because the pressure can warp and indent the wood. Look for a pressure washer with a strength between 1500 and 2000 psi and steer clear of models with an engine over this.^{[3]
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2
Snap on a 25-degree tip. A 25-degree tip on a pressure washer will fan out the water for a gentler wash. Attach a green 25-degree tip onto the end of the pressure washer sprayer. Whether you rent or own a pressure washer, you should have a variety of color coded tips and a 25-degree is typically green.^{[4]
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3
Stand two feet away from your fence. Regardless of the tip you attach or the strength of your pressure washer, it’s a powerful tool. Make sure you stand at least 2 feet (0.61 m) away from your wood fence to prevent any damage.^{[5]
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4
Spray the water in long, even strokes. Standing 2 feet (0.61 m) away, use long, even strokes to spray off debris and bring your wood fence back to life. Slowly move the spray tip 1 foot (0.30 m) closer to the surface and spray the length of the fence using even strokes until the wood looks brighter.
5
Vary the areas you concentrate on. Don’t damage your wood fence by spraying too long in one spot. Change the area you’re spraying frequently. After you’ve brightened several fence posts using long, even strokes and you don’t see any more color change on the wood, move over to the next set of fence posts.^{[6]
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6
Use an 18-degree tip for added cleaning. If your fence is not coming as clean as you'd like it, change the pressure with an 18-degree tip. Snap off the 25-degree tip and snap on an 18-degree tip. The added pressure should be enough to clean your fence spotless without damaging it.

Part 3

Part 3 of 3:

Washing By Hand

1
Use oxygenated bleach on a wood fence. Mix together an oxygen bleach powder, like Oxiclean, according to the manufacturer's directions. Apply the mixture to a water dampened fence with a large painter’s brush, leave it for 15 minutes and then scrub the surface with a plastic, bristle scrub brush. Rinse the mixture and any remaining residue with a garden hose.
2
Remove mold and algae with chlorine bleach. Get rid of green residue from algae or mold by mixing two parts water to one part chlorine bleach. Add a teaspoon of dish soap for extra cleaning power and scrub grime away with a bristle brush. Concentrate and use a little elbow grease on stained areas. Rinse your wood fence off thoroughly after you scrub all areas down.
3
Use a commercial wood cleaner. You can also buy a pre-mixed cleaning solution to clean your wood fence by hand. Go to your local hardware or home improvement store and look for a cleaner specifically for wood. They will often be geared towards wood fences and decks. Follow specific instructions given by the product's manufacturer.
4
Use white vinegar to remove mildew. Mix ¹⁄₂ cup (120 mL) white vinegar to one gallon of warm water to remove unsightly mildew or moss. Apply the mixture with a sponge, let it sit for 15 minutes and scrub your fence with a bristle brush. Rinse with water from a garden hose thoroughly afterward.

Community Q&A

Question

Be sure the bleach is fully rinsed before applying vinegar -- mixing the two can cause deadly gas!

CageyCat

Top Answerer

You are absolutely correct. Some chemicals should never be mixed. Further, some chemicals should never follow the deadly-mix chemical. Use one-- or the other -- not both, not even if rinsed.
Question

Is chlorine bleach the same as chlorine from a pool store?

Community Answer

No, the pool store chlorine is approximately 10% chlorine. Store bought chlorine bleach is 1.5 -3% chlorine