5 Helpful DIY Steps On How To Remove Mildew From Wood Deck

No matter what type of wood floor you got for your home, molds live everywhere. There will come a time when you’ll learn how to remove mildew from wood deck so you can save your decking boards from being totally inoperable.

Whether the mildews have penetrated on the wood pores or just starting to make a living on the wood surface, you can remove them and might as well shut off their chance of returning. What you’ll need is a bit of hard work, proper cleaners, and an ounce of patience, then you’re equipped enough to salvage your wood deck from rotting or decaying. 

how to remove mildew from wood deck

Fortunately, there are easy-to-follow steps to completely get rid of stubborn mildew from your wood deck. You can also have a chemical-free treatment to avoid degrading the wood material.

Here, we’ll guide you on your mildew housework. We’ll also hand you tips to prevent any mildew breakouts from keeping your wood deck purposeful and enjoyable for relaxing.


Why Does My Wood Floor Grow Mildew?

Maybe you have a slight idea of how mildews grow even on your wood deck. However, it is not surprising for a wooden floor that receives a relatively fair exposure to sunlight and has a high density.

Mold and mildew naturally live in moist areas, and your wood deck is a perfect home for them. Any water left sitting on your decking board would provide food for mold.

Fallen leaves, twigs, or any debris left unswept from the floor can also cause mildew growth as they breed fungus. Some of these mildew-causing fungi can be very hazardous to health.

Fungi, known as wood-eaters, can appear in a greenish-black color. They are referred to as Stachybotrys chartarum, which can victimize your wood floor.

Should you want to know more about this kind of mold, here’s an informative article on what does Stachybotrys mold look like.


Removing Mildew From Wooden Deck

To properly get the work done, you need to follow each step diligently.


Step #1. Preparing tools and protective gears

Before the removal steps, you’ll have to protect yourself from any harm molds and chemicals can cause. Put on protective apparel such as rubber gloves, eye protection, and protective suit and shoes in cleaning the mildew.

Also, check for a bucket or spray bottle (depends on your chosen solution), scrub, and water hose.

While you’re at pre-cleaning procedures, you’ll want to ensure no plants near the cleaning area. Keep them away as chemicals can damage your sensitive plants.

Also, before scrubbing the mildew off the deck board, it’s necessary to sweep away any debris on the deck surface. Ensure to clear out all the corners from pollen, leaves, and twigs.


Step #2. Choosing a cleaning recipe

You’ll have to choose your fighter—clean solution in this step. We include recipes for each cleaner, so you’re also guided on preparing them.

  • Oxygen bleach – To prepare the solution, mix 2 gallons of warm water, 2 cups of oxygen bleach, a quarter cup of dishwashing soap, and a cup of Borax together.
  • White vinegar – For the solution, mix an ample amount of water with white vinegar, then pour them into the spray bottle.
  • Liquid detergent – A combination of 1/3 cup of detergent and a gallon of water will do the trick.
  • Baking soda – The recipe combines a gallon of warm water and a cup of baking soda.
  • Trisodium phosphate or TSP – To prepare, add a cup of TSP to a gallon of water.

Aside from these homemade cleaners, you can also choose commercial deck cleaners with mildewcide properties. Just be careful about using them.


Step #3. Applying cleaning solution

You can pour and spread the cleaner on the molded area. You can also use the sprayer to concentrate on the affected deck parts.

Leave the solution for five to ten minutes. If using the white vinegar solution, leave it dry for an hour.


Step #4. Scrubbing or wiping the mildewed area

After letting the cleaner dry, it’s time to scrub away all the mildews. Remember to use a firm but soft-bristled brush to avoid damaging the wood finish.

Use a rag or cloth to wipe the mold stain off the deck for vinegar solute.


Step #5. Rinsing and drying wood deck

Finally, after obliterating the mildew stains, use the water hose to rinse away all the remaining cleaners and water from the wood deck.

If there are any, roll your awnings to allow sunlight to dry the surface. Using a dehumidifier can also speed the drying.


Mildew Prevention On Wood Deck

You don’t know that molds can decay wood in no time, especially when you didn’t give it adequate attention. If you need an additional guide, here’s an informative post on how long does it take for mold to rot wood.

The best thing you can do to prevent mildews from making your wood deck their dwelling place is to make the site unideal for them. Here are the ways to do it:

  • Keep the deck dry by ensuring that it gets sunlight each day and has no water sitting on it.
  • Clean the deck regularly by sweeping away pollen, fallen leaves, and other debris.
  • Apply water sealant that has quick-drying ingredients and has herbicide properties.



It’s a relatively good thing that the ways on how to remove mildew from wood deck don’t require that much hard work. They are also easy to heed and won’t cost you much money.

Just remember that if the mildew infection gets severe, you may need to completely tear down and replace your wood deck — but this time, with experts’ help.

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