How to Remove Mildew & Algae From a Wooden Fence

It's the kind of backyard discovery that can stop you dead in your tracks: The presence of mildew and algae on your wooden fence. In all likelihood, this section of your fence got wet, stayed wet and was shaded from the sun -- three conditions that allowed the mildew and algae to grow. But now's the time to take the upper hand. If you don't have a pressure washer, you'll want to rent one. It's the best and most efficient way to eradicate the problem.

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Read the instructions carefully before using a pressure washer.

Step 1

Clear a wide path around the section of fence you will be working on. Set breakable objects and container plants out of the vicinity.

Step 2

Remove dirt, cobwebs and other surface debris from the fence with a hose or the pressure washer. Attach the proper tip to the pressure washer; it might require different tips for water only and water mixed with detergent.

Step 3

Add a quarter-cup of liquid laundry detergent -- it will dissolve faster -- and a quarter-cup of bleach for every gallon of water in the power washer bucket, sometimes referred to as the reservoir.

Step 4

Test the solution -- and your technique -- on an inconspicuous section of the fence. Standing at a distance of about 2 feet from the fence, hold the nozzle of the pressure washer at a 45 degree to the fence. This will allow the mildew and algae to simply slide down the fence, away from you. Move the nozzle in a constant side-to-side motion.

Step 5

Rinse the fence with water only, either with the pressure washer or a hose. If stubborn spots of mildew or algae linger, repeat the process on those problem areas, but wait for the fence to dry first.