How to Prevent Bees from Nesting in Your Deck

Bees, particularly carpenter bees, view your deck as a prime piece of real estate for their spring nurseries. A deck is essentially a giant, pre-cut log waiting for a tenant; once they start boring into the wood, they compromise the structural integrity and invite moisture-related rot. Done well, prevention is about closing off entry points and modifying the surface so the wood no longer serves as an attractive target. Stopping the invasion before it starts is infinitely easier than dealing with an established colony. By sealing your wood and eliminating the dark, narrow crevices that bees crave, you effectively take your deck off the market. It requires a bit of maintenance, but keeping your wood sealed and your seams tight ensures the bees move on to a less hospitable home.

  1. Strip the Weathered Surface. Pressure wash or scrub the deck thoroughly to remove dirt, mold, and any old, flaking finish. Once dry, inspect every board for existing holes or soft spots that indicate past nesting activity.
  2. Lock in Protection Now. Apply a high-quality exterior wood stain or paint to every side of the deck boards. Focus heavily on the underside and ends of the boards, where the grain is most exposed and vulnerable.
  3. Eliminate Hidden Entry Points. Use an exterior-grade wood filler or silicone caulk to seal gaps in the framing and structural joints. Keep the deck structure tight so there are no narrow openings for bees to squeeze into.
  4. Deploy the Natural Barrier. Mix a solution of boiled citrus peels and water in a spray bottle. Spray this mixture along the undersides of joists and areas where you have seen bees hovering, as they dislike the scent of citrus.
  5. Block Access Below. Install fine-mesh screen or hardware cloth over large gaps in the deck's foundation or decorative skirting. This prevents bees from accessing the dark cavities beneath the decking surface.
  6. Catch Early Warning Signs. Walk the perimeter of your deck once a week during the spring to look for signs of sawdust or 'frass' under specific boards. Early detection allows you to intervene before a colony becomes established.