How to Remove Sap From Deck Boards

Sap oozes from trees, leaving a syrupy substance that tenaciously sticks to deck boards. After exposure to the air, sap hardens on surfaces, becoming a dense and rigid mound. Prying the solid sap loose from deck boards may result in removing part of the timber. The sap requires a cleaning agent that softens the substance so it releases from the deck without damaging the wood.

  1. Mix 1/4 cup of oxygen bleach into a bucket of water.

  2. Dip a rag into the solution, and wipe it onto the sap on the deck boards, saturating the stain. Leave the rag on top of the sap. Allow the bleach to work on the stain for 10 minutes.

  3. Remove the rag, and clean the sap from the deck with a soft-bristled scrub brush. Wet the brush with the oxygen bleach, and scrub until the sap releases from the deck.

  4. Rinse the bleach from the deck with a garden hose or with buckets of water. Ensure the bleach is completely rinsed from the deck boards.


  • Do not use chlorine bleach on wood deck boards. Chlorine can strip the wood of color and destroy the timber. Chlorine bleach also kills nearby vegetation.