How to Tell If Deck Wood Is Rotten?

Without proper water sealing, wooden decks may experience wood rot. Water remaining on wood for long periods of time seeps into the porous surface, swelling deck planks. The absorbed water creates soft or spongy areas, rotting the wood and compromising the integrity of the deck. The deeper the wood rot, the more likely the wood needs replaced with new deck boards. A slight penetration of wood rot may allow you to save the wood by an application of water sealant to keep the wood from absorbing any more liquid.

Check for wood rot in your deck with a screwdriver.
  1. Check the deck wood for soft, spongy areas. Walk over the entire deck and stairs, feeling for soft spots by pressing with your shoe.
  2. Run your hand over the railings looking for spongy areas. Get under the deck and tap different areas with a screwdriver. Examine the deck posts for soft spots.
  3. Stick a screwdriver into any soft areas of the wood you find. If the screwdriver penetrates more than 1/2 inch deep, replace the wood piece. If the rot is less than 1/2 inch deep, apply a water sealant to the entire deck to stop wood rot from becoming worse.

Things You Will Need

  • Screwdriver


  • Remove standing pools of water from decks by sweeping away with a broom or blowing dry with a leaf blower.
  • Remove debris such as wet leaves or grass from the deck by sweeping them from the surface.
  • Keep drainage from gutters directed away from the deck.

About the Author

Constance Barker, located in the hills of southern Ohio, is the owner and writer of several financial, credit report and travel websites. She started writing in 1999 for private clients and began creating website content in 2004. She gained expertise in home improvement after she and her husband built their home themselves.

Photo Credits

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