Repair Carpenter Bee Damage

Repair Carpenter Bee Damage

By Matt Weber

 Some bees leave bullet holes. Here’s how to fix them.

I assume that carpenter bees were named for their affinity for wood, because they do love to chew it up. However, carpenters use wood to build things, whereas carpenter bees tend to damage the wood in whatever you’ve already built. In that regard, maybe we should rename them “vandal bees” or “tiny saboteurs.”

More than 500 species of carpenter bees exist throughout the world and nearly all of them burrow into dead wood to nest and lay their eggs. They don’t actually eat the wood, but chew it up and then messily discard it around the hole they’re digging. The bees typically burrow into the underside of a board or beam, such as a deck joist or fence rail, leaving signature piles of sawdust beneath the nesting location. The entry to the nest is typically a round hole that is approximately 1/2 in. wide. Although each nest has a single entrance, the nest may have many adjacent tunnels hidden within the wood. This network of tunnels can weaken the structural integrity of the boards, which is why it’s important to stop these diminutive flying drill bits from rendering your outdoor wood to Swiss cheese.

Damage Control

My first attempt at repairing bee damage involved filling the holes with wood putty and/or caulk. Whereas this can eventually work, it can also take a lot of time and reapplication. Because the bees displace so much wood, it takes a lot of product to fill the holes. When the holes are filled with a lot of goop, you can expect shrinkage once the product cures. When the product shrinks, the hole is no longer completely filled, requiring at least another round of caulk or putty—and possibly even more.

For a better method of damage repair, I turned to Rob Baugher of Baugher Design & Remodeling in Birmingham, Alabama. Rob is a friend of EHT who hosts the Our House radio show on Saturday mornings. He suggested the dowel-plug procedure that we detail in this article, which proved to be much more effective than gooping the bee holes.


Locate and mark the damaged areas

1. Locate and mark the damaged areas. Small piles of sawdust beneath the underside of wood boards are the calling cards of carpenter bees and will help you pinpoint the holes.

Inspect the structure thoroughly

2. Inspect the structure thoroughly, because one nesting hole often indicates a broader a problem with multiple areas of damage.

Photo gives a peek inside a nesting hole

3. This photo gives a peek inside a nesting hole, where the adjacent tunnels are visible inside the wood.

Measure the diameter of the hole

4. Measure the diameter of the hole.

Use a wood plug

5. Choose a wooden dowel of the appropriate diameter to use as a wood plug. I purchased a couple of different sizes to accommodate different holes.

Soak a cotton swab

6. Soak a cotton swab with isopropyl alcohol.

Shove the alcohol-soaked swab deep into the nest

7. Use a small dowel or stick to shove the alcohol-soaked swab deep into the nest. The alcohol displaces the oxygen, so no bees or larvae will survive to burrow out of your repair.

Choose a dowel

8. Choose a dowel that will achieve a tight fit. This may require whittling the end to size with a knife.

Coat with exterior-grade wood glue

9. Coat the end of the dowel with a quality, stainable exterior-grade wood glue.

Twist the dowel tightly

10. Twist the dowel tightly into the hole as deep as it will go.

Cut off the excess dowel

11. Cut off the excess dowel. An oscillating tool is perfect for easily cutting the dowel, but a mini hacksaw will also work in a pinch.

Touch up the repair

12. Touch up the repair with some matching wood stain, and then repeat the procedure for the other areas of damage.

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