Black Mold and why it Grows in Certain Deck Stains
Exterior deck stains are subjected to the elements making them prone to natural contaminants. A deck stain is there to shield the wood from harsh weather and the damage it can cause such as rot and decay. In providing protection sometimes the deck stain itself can be compromised.
Black mold is one of the natural occurrences that can affect a wood stains effectiveness and longevity. There are several reasons why black mold can grow on or in a deck stain but here are the most common reasons.
Over Applying Deck Stain
When a deck stain is over applied to the wood it can affect the curing or drying time of the stain. When this happens the deck stain remains tacky for several days or longer allowing dirt and tree pollen to become embedded. Once these contaminants have intruded the stain they can attract and begin to grow black mold even after the stain finally cures.
Tips: To avoid curing issues by over applying a wood stain, work in small areas or one board at a time. Let the stain soak into the wood for several minutes then use a brush or a stain rag to wipe any excess drips or puddles.