This post was updated on April 4, 2025
Best Deck Cleaner to Remove Mold on Decks
Since we’ve published this article, we have received some input on the best deck cleaner for mold on decks. Here at DeckStainHelp.com, we take pride in the fact that we have become the Internet’s go-to source for all things exterior wood and deck restoration-related. Like before, we appreciate your input, so feel free to leave a comment below and pictures of your deck stain projects.
Wood decks are not naturally resistant to mold. When speaking of “mold” on decks, mold is a general term people commonly use to describe what might be moss, lichen, green algae, mildew, or other types of fungal growth. Mold is like the universal word to cover anything green or spore-like growing places it should not be growing like on your deck. Mold on decks can cause problems besides just being treacherous to walk on when wet. The issue with mold on decks can range from completely unsightly to decay, wood rot, and major structural damage. The good news is that mold can be removed from decks using common deck cleaning methods.
The best way to rid mold on decks is to use the right cleaner. The best deck cleaner for mold on decks is not bleach. Bleach will kill mold but it can also break down the cellular structure of the wood fibers and dry out the natural oils. Avoid using bleach for wood cleaning at all costs. Bleach-based deck cleaners should also be avoided as they can damage the wood’s lignin. In addition, bleach is only an average cleaner of dirt and grime that also need to be cleaned from the deck prior to staining.
The best deck cleaner for mold on decks is an oxygenated deck cleaner. These cleaners contain sodium percarbonate, which is an EPA registered active ingredient for removing mold and mildew. The oxygenated deck cleaners are concentrated powders that are mixed on-site with water. They contain bonus surfactants that aid in boosting the total cleaning effectiveness. When used in combination with a pressure washer or deck brush, oxygenated cleaners are particularly successful at cleaning mold from decks.
Choosing the best deck cleaner for mold on decks can be easy by doing an online search for oxygenated deck cleaners. Deck cleaners like Restore-A-Deck Wood Cleaner, Defy Wood Cleaner, and Messmers Wood and Deck Cleaner are just a few that are commonly used by professionals. To remove mold on decks is just a matter of using the right deck cleaner.
Best Cleaner for Mold on Decks
The RAD Guard will remove the black mildew and green algae stains from your wood and deck stains and will prevent them from returning for 1-2 years: RAD Guard Mildew and Algae Cleaner and Preventer
| Image | Title | Price | Add to cart | Rating |
|---|---|---|---|---|
 | $49.99 | |||
 | $119.99 |
The Best Deck Cleaners for Mold Video – DeckStainHelp.com
I’ve got a new redwood deck that is growing mildew like crazy, What can I use to kill the mildew?
Are you sure it is mildew? Post some pics in comments.
Actually I miss spoke. It’s mold.
When you prep for staining, the mold/mildew will come off. Look at this for prep:
https://www.deckstainhelp.com/restore-a-deck-cleaner-system-review/
Best then treat with a stain that does not attract mildew/mold.
https://www.deckstainhelp.com/restore-a-deck-wood-stain-review/
After it is stained, you can try this over the stain to help prevent the mildew from returning:
https://www.deckstainhelp.com/rad-guard-mildew-cleaner-preventer-review/
I have a cedar deck that I sanded and restained last year. Over the winter, mildew has grown on the deck. Is there a light mildew cleaner I can use that won’t disrupt the existing stain? It doesn’t need restaining this year.
No, you cannot just remove the mildew and not have to restain.
Oh no! This makes me so sad.
I have a deck made from plastic bottles that has a greenish mold on some of the railings. What should I use to clean it up?
Try this: https://www.deckstainhelp.com/defy-wood-deck-cleaner-review/
The deck isn’t wood. It is made from plastic milk bottles. What works with that?
The brand we suggested will work.
A customer of mine has a ipe deck that is a mess… dirt, mold, algae, lichen, and heavy weathering has left the wood rough. To boot there are stainless steel screws that were left proud, meaning not recessed or even flush, that would need to be driven deeper so that they could be sanded over. My question – Would pressure washing, cleaning, brightening, and staining with Defy Hardwood stain yield a beautify finish, or would skipping sanding leave the ipe too rough to look good? Thanks, Jon
You do not need to sand this. Use a deck cleaner and pressure washing to prep and brightener after.
How to I keep my mahogany decks clean from mildew and mold but keep the grey color
You will need a deck cleaner to remove any mildew and then try a clear sealer that will gray naturally over time. Defy Extreme Clear would alos help with any mildew prevention.