Every Spring we answer phone calls as folks cleaning up from the previous Autumn leaf fall. After the sweeping has concluded, they see tannic acid stains on their cement and deck.

Tannic who, wasn’t that the ship that Leonardo DeCaprio  was on and sunk?

Tannic acid while you may have never heard of it, it is something that most of us come across every day. Tannic acid occurs naturally in the roots, leaves and barks of some plants, remains the main culprit in stains from coffee and tea. These are the same stains that occur on your deck and cement from leaf decay.

Thankfully, a spot doesn’t necessarily mean the cement or deck is stained forever, but for certain it much easier to prevent than it is to clean up months after the staining originally took place. Newer decks and fresher cement are particularly susceptible to staining.

Further, tannic acids are damaging to deck seal or stains not only because the leaf decay will wear away the protective layer but it can permanently damage the color of the stain.

Prevention is simple- Several times per week, during peak leaf falling time blow, sweep or rake your leaves off your deck, cement, patio or walkway. Don’t let leaves sit after a rain, as rain inhibits the decay process and release the tannic acid faster.