Things You'll Need
Hose with sprayer attachment
Powdered oxygen bleach
Garden sprayer or spray bottle
Soft-bristled scrub brush
Pressure treated wood has been around for 70 years; the process of treating wood was first invented by Dr. Karl Wolman. This wood has infusions of chemical preservatives deeply imbedded into the wood fibers to help protect it from insects and mold. Although pressure treated wood is highly resistant to molds and mildews, extreme exposure to wetness and humidity may still form a buildup of mold and other grimy debris that is unpleasant to look at and unsanitary. You can clean and disinfect pressure treated wood with an oxygen bleach solution.
Put on protective gear, such as eye goggles and rubber gloves, before attempting to clean treated wood with an oxygen bleach solution. If you are cleaning mold, wear a protective face mask as well.
Do not attempt to immediately scrub the wood if there is mold on it as this can release spores. Lightly spray the wood with water first to remove any excess dirt and debris.
Mix an oxygen bleach solution of one part powdered bleach to nine parts water in a garden sprayer or spray bottle. Heavier soiling or deep green or black mold on your wood can go with a stronger solution of one part oxygen bleach to four parts water.
Spray all exposed areas of the treated wood with the bleach solution. Scrub any areas of extreme soiling lightly with a soft-bristle brush.
Rinse the bleach solution off the treated wood with a garden hose with a sprayer nozzle attached. Allow the wood to dry thoroughly before applying any sealants or stains.
Oxygen bleach is more environmentally friendly than chlorine bleach and is nontoxic to humans, animals and plants. Consider applying a wood sealant to help protect treated wood from the elements. Apply most sealers once every two to three years to keep wood properly protected.
Chlorine bleach can destroy lingin in your wood deck and cause bleaching of the wood.