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.