How to Remove Mildew from Wood Deck [5 Fast Methods]

A solution of oxygen bleach and water is one of the best ways to remove mold and mildew from your wood deck. It is gentle on wood and kills mildew quickly. Using a pressure washer to remove mold is another excellent option. Alternatively, you can use a commercial mold, algae, and moss remover. Otherwise, homemade solutions using laundry detergent and sodium triphosphate work to scrub your wood deck clean without causing damage to your deck.

How to remove mildew from wood deck

Is There a Difference Between Mold and Mildew?

Black, white, and even pink growths commonly referred to as mildew are actually forms of mold. So, all mildew-killing strategies are mold killers as well. The mildew-removal strategies included below are also capable of killing black mold, green mold, and most species of moss and algae.

Does Vinegar Kill Mold on Decks?

While vinegar does kill mold growth on wood surfaces, such as decks, it is not recommended that you use vinegar as a deck-cleaning solution. This is because vinegar contains acetic acid, a compound that destroys deck finishes. If your deck is made of unfinished wood, vinegar can help remove mold and mildew. However, you should never use white vinegar or any other type of vinegar to scrub a deck that has been painted or finished.

5 Methods to Quickly Remove Mildew From Your Wood Deck

Mildew growth on wooden decks can turn an enjoyable outdoor space into a dingy-looking disaster. However, it’s relatively simple to clean mildew off your deck and kill any mold spores that are present. Here are the best methods for the job:

Oxygen Bleach

A paste of powdered oxygen bleach and warm water is one of the best mildew removers you can use. Oxygen bleach is strong enough to scrub away mildew but is gentle enough that it won’t harm your deck’s finish or discolor the wood.

  • Mix this oxygen bleach with warm water until you have a paste with cake batter consistency.
  • Spread the paste onto mildewed portions of your deck.
  • Use this soft scrub brush to scrub the mildew off your deck.
  • Wash the paste away with water from your garden hose.
Chlorine-Free Bleach
Charlie's Soap | Oxygen Bleach Powder
  • This bleach product is chlorine-free.
  • Color-safe, while also being effective.
  • Can be used for a variety of purposes.
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Do not use chlorine bleach instead of oxygen bleach. Not only is it less safe for the environment, but you also run the risk of discoloring your wood with chlorine bleach. Stick to oxygen bleach only for this job.

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Pressure Washing

A pressure washer is a great way to remove mildew and mold from your deck. A simple garden hose doesn’t have enough power to scrub away mildew. Instead, rent a pressure washer from your local hardware store.

  • Rent a power washer from your local hardware store to quickly remove mildew from your deck.
  • Begin at the lowest spray setting to remove mildew without damaging your deck.
  • Only increase the pressure as needed for mildew removal.
  • Cleaning your deck surface with a pressure setting that is too intense may ruin your deck’s finish.

It’s essential to use the gentlest spray setting when using a pressure washer to clean mildew off your deck. An aggressive spray will strip the finish from your deck and may leave your wood with a “fuzzy” texture. Start gently, and work slowly rather than risking damage to your deck from a powerful spray setting.

Mold and Algae Remover

A commercial deck cleaner designed as a mold, algae, and moss remover is a great way to get rid of stubborn mildew on your deck. Simply follow the product directions to easily remove mildew quickly.

  • Use this mildew and mold remover for your wood deck.
  • Specialized mildew-killing compounds are gentle on painted and finished decks.
  • Commercial products designed for use on homes are gentler than most homemade mildew-killing formulas.

One of the top advantages of using a mold and mildew solution is that these products are designed to remove mildew without damaging finished surfaces. A product that will kill mildew without removing paint is an ideal cleaner for your deck.

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Laundry Detergent

You can make your own mildew remover by mixing ⅓ cup (75 ml) of laundry detergent with one gallon of water (3.75 liters). Then, simply use this solution and a soft scrub brush or soft-bristled broom to scrub the mildew away. This works quickly, is gentle enough to use on finished decks, and the runoff won’t harm nearby plants, animals, or grass.

Trisodium Phosphate

Trisodium phosphate is a powerful cleaning product that can kill mildew and mold spores without harming your deck. However, you should always use heavy-duty protective gloves when using trisodium phosphate. To use it to remove mildew, mix 1 cup of this trisodium phosphate in one gallon (3.75 liters) of clean water. Then, use this solution in combination with a scrub brush to remove mildew from your deck.

How Do You Remove Mildew From a Wood Deck?

The best ways to remove mildew from a wood deck are:

  • Use a paste of oxygen bleach and water to scrub away mildew.
  • Rent a pressure washer to scour mildew from your deck.
  • Use a commercial moss, mildew, mold, and algae remover.
  • Make a cleaning solution from water and laundry detergent.
  • Use trisodium phosphate mixed with water to create a powerful mildew-killing scrub.

Each of these methods is chosen because it’s both effective at removing mildew and gentle enough that it can be used on wood decks without damage. With just a scrub brush and some simple ingredients you can easily make your deck a pristine outdoor space.

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