Keep Carpenter Ants From Drilling Into Your Deck By Opting For This Kind Of Stain

Carpenter ants can be a serious problem for decks. These wood-destroying insects are unpleasant to look at, but the real problem is the damage happening below the surface. Carpenter ants don't eat wood like termites do — they tunnel through it to create large galleries and nests. This gradually weakens the structural beams of your home and deck, making them less stable and more expensive to fix. There are many ways to banish carpenter ants from your home, but the best way is to keep them from moving in to begin with. 

Since carpenter ants look for wood that has been damaged by water, like rain or snow, decks are a great place for them to live. However, there is something you can do to stop these ants from getting a foothold. Given how much is at stake, it's best to treat your wood deck with an oil-based stain that will allow for the formation of a better moisture barrier. Oil-based stains soak deep into wood fibers, while water-based stains mostly sit on the surface. That deeper penetration helps keep wood drier and may help deter these pests.

However, it's important to note that even the best stain won't stop ants if the wood is already rotting from the inside. Before staining, inspect the "hidden" parts of your deck — like the ledger board and joists — to ensure no moisture is trapped against the house. Trapped moisture around your deck often indicates a hidden leak or poor ventilation caused by debris, which can lead to structural rot. If you find dampness or soft wood in these areas, it's best to call a professional contractor or inspector to address the source of the leak before proceeding with your DIY project.

Homeowners should always watch out for signs of carpenter ants invading their home, but taking preventative measures upfront is also worthwhile. Oil-based stains help address the excess moisture carpenter ants are drawn to, and many modern formulas also contain mildewcide. By limiting the growth of rot-inducing fungi, you help reduce the moist home that carpenter ants love. Essentially, oil-based stains keep the structural integrity of the deck strong, deterring drilling insects.

Wood, especially wood decks, naturally expands and contracts with temperature changes. Oil-based stains remain flexible within the grain, which helps prevent cracking in the wood where ants typically enter. These stains can also help seal small gaps with a water-repellent protective layer. And, since most oil-based stains can last about two to five years, they provide a long-term defense that reduces the frequency of maintenance while keeping the wood impenetrable to pests. If you do find a carpenter ant nest, which looks like smooth galleries or tunnels carved into the wood, contact a professional exterminator immediately to assess the infestation and any structural damage.