Letter: Carpenter Bees and Boring Beetles


My husband and I have purchased a log cabin, which we are moving into in a few months. This cabin is located in SW North Carolina, and the property is surrounded by a national forest. We are dealing with carpenter bees and boring beetles. My husband has been looking into all sorts of ways to deal with these wood-damaging insects. He just bought hypodermic syringes from the local farm store to put liquid borate in them for injecting into the holes we can see. We need a permanent solution, if there is such a thing, to keep them at bay. My husband is convinced for our first winter here we will have to go around the building injecting the holes we can see.

There seems to be a major shortage of good workers up here who can help us out, so for now we will take steps and hopefully by spring there will be some better suggestions on how to deal with the outside of our cabin. He has read up on stripping the paint off the logs by a method using corn cobs, then spraying those raw logs with bug deterrent to soak into the wood, followed by finishing clear coat. This of course, is pricey. $64,000.00 was a recent quote for the size cabin we have.

Also, we have read adding Bora Care to paint to give her a coat for the winter won’t really help, so painting the building just for the winter is throwing good money into the air. The house also is in bad need of caulking, as the previous owners used the wrong caulk that shrunk, leaving a drafty home. We have some work cut out for us. I am curious to hear from other log cabin owners who have some ideas for us.


  1. Instead of a syringe, get a 1 or 2 gallon pump sprayer at your local home improvement store and spray, either a tight stream-shot at each hole, or a general over-coat type spray to deal with the current holes.

    Longer term, if you don’t want to use chemical insecticides, you’ll have to figure out what would repel or kill that you can spray as a topical.

    Good luck.

    1. I have my second cabin now and used a product called Lifetime which has worked well. Be sure to plug the holes with dowels after spraying insecticides. There are straps u can make search online.

  2. Log cabin owner,
    I am the owner of a pest control company in SW Virginia and am very familiar with the problem you are having. The best solution is to finish treating all the holes as you have been doing, filling them in, and then following up with a minimum of 2 coats of stain/ paint/ clearcoat(3 is ideal). You will need to apply an additional coat every 5-7 years to keep the structure weather/bug proof. One alternative( if the aforementioned cannot be done) would be a full exterior treatment of the structure with Tempo Ultra WSP. You may have to do this 2x(April 15 and May 30) but you need to have the ultimate goal of sealing the exterior of the structure. Your log home’s longevity is dependent upon protection that a good sealant will provide from both weather and insects.

    1. I believe Jeff, the pest control company owner, is correct.

      I’m a member of a log home builder association, and this same method of filling in the holes is discussed on our private forum.

      I don’t think you’ll have much luck with injecting bora care, since carpenter bees don’t actually “eat” / ingest the wood- they just “drill” it.

      I’m building a log home right now. Last year, carpenter bees attacked some of our logs while we were stacking them. I researched it and found that filling in the holes is a good preventative measure, along with fighting them off every time you see one. We tried the latter early this year, and I haven’t seen any since then. You must stop them from getting established- once they see a hole, it attracts others to make more. Wood filler would be my solution for the existing holes. Bee traps made from mason jars are easy to make, and I’ve heard from other members in my organization that they do indeed work.

      I also like the inflated paper sack idea. 🙂

      As far as the caulk- I would steer clear of any silicone based caulk on logs. Since silicone doesn’t “breathe”, it can cause water to pool around it, causing the logs to rot. I suggest a mortar based chink to allow the logs to breathe.

  3. We have had trouble with carpenter bees; hornets are their arch enemy, we inflated a large paper sack and hung it from the rafters- no more carpenter bees!

  4. I grew up not to far north of your cabin all the old people used a combination of burnt motor oil and diesel fuel to paint all houses and buildings.It sounds weird but it works.Hope this helps.

  5. Don’t despair! My wife and I bought a cabin a few years ago and then learned that carpenter bees were attacking it every spring. Dozens and dozens of them. Folks will tell you that pesticides don’t work on carpenter bees, but that’s simply not true. We called a local pest control company. They sent two men out who went around the house and squirted boric acid powder into the holes and then sprayed the cabin with an EPA approved, water-based insecticide specifically for carpenter bees. Problem solved. The water soluble chemical soaked into the wood and the carpenter bees were gone. I’m sure some folks will object to the idea of using a chemical insecticide, but this is one instance where modern science has developed products that work, and the government makes the manufacturer establish that the product is safe. Best of luck!

    1. Your right ACC! There are modern insecticides available to protect homes from harmful insects. … They’re similar in effect, to modern antibiotics used to cure diseases in people. … With insecticides it’s possible for homeowners to follow the directions and inexpensively apply the insecticides themselves.
      As a note: For $64,000 (For one possible ‘cure’ for the problem), it would be possible to buy a modern ‘Tin-House’ ~ and live as ‘snug as a bug in a rug’ during the Wintertime. [People would use insecticides if they had bugs in their rugs; ~ especially in their toupees.]

  6. We built our log home in the Ozark Mountains 20 years ago. We have used Tim-Bor about every 4 or 5 years. Follow directions, adding it to your stain/sealer. It has worked Great for us!

  7. Look on Amazon for pictures of carpenter bee traps to see how they are made. They can be purchased for a lot less money at many feed stores or hardware stores. They are sold on line at Walmart also. They really work. The bees go in and can’t get out.

  8. My wife and I owned a log home surrounded by old growth hardwood forests in NE Illinois near the Wisconsin state line for over 16 years. Your story is very familiar to us. First, cob blasting the house and refinishing it will make the house look a whole lot nicer and serve to protect the wood. Rechinking will reduce air infiltration. What all this will not do is solve your carpenter bee problem long term. We had our house cob blasted, sprayed for bugs, and rechinked twice in the 16 years we owned it. It did not solve the carpenter bee problem. Bottom line, a log house is built of dead and decaying wood, even if its decaying very slowly. Carpenter bees can smell that and are drawn to it. We found that the best way to deter them without using toxic chemicals was to coat the areas of the house they were drawn to with Almond Oil. Our online research taught us that carpenter bees didn’t like the smell of nuts. The almond oil worked pretty well, but was not fool proof. For one it would wash off in the rain or would dry out requiring reapplication every two weeks or so. The window of time where the carpenter bees were active in attacking our house was in the spring, May and June in northern Illinois. At some point they stopped and we were good until next year. I would immediately dust any holes that did get drilled with bug powder in case there were any bees in the hole, and then seal the holes with wood filler and restain the plug for appearance. The bees seemed to be most attracted to the cedar fascia and soffit. The rest of the house was Engelmann Spruce, which did get some attention from the bees, but not nearly as much as the cedar.

    As you are finding out, a log home is a lot of work and a labor of love. We really enjoyed living in ours. The wooded setting and the rustic atmosphere is something we cherished. That said, we’re more than happy to have sold our log home. We were even happier to get out of Illinois. Our new home in Wyoming is built of insulated concrete forms with a stone exterior and very little exposed wood. After 16 years in a log home, low maintenance is our motto now. Best of luck.

  9. I use peppermint essential oil ( buy from fpiamerica) in bulk its about 30.00 per liter if I remember. You mix 1 gal water , 1 tablespoon dawn detergent and 1/2 oz peppermint oil in a sprayer- spray around the area (protect your eyes) this gets rid of spiders and mice also- helps keep cats away from uprooting plants near the area. It last approx 3-4 weeks unless you apply and have a hard rain within hr or so. Makes the area smell nice too. It also kills hornets and yellowjackets too unless you spray honeybees directly it’s safe to use.
    I suggest one pick up a book about oils could be useful in the future.

  10. WD-40 sprayed in active holes will kill the bees. If there is wood dust under the hole, the bees are in there. Use the applicator tube, work it into the hole and give it a good squirt. Once squirted they live just long enough to crawl out and fall dead. The holes will attract other bees. I plug the holes with construction adhesive to prevent other bees from entering the holes. Add bee traps and you will reduce your bee problem to nearly nothing.

  11. $64 grand to strip and repaint the house is outrageous.

    unless its a really really big house.

    carpenter bees are not too hard to get rid of.
    we just gave our kid a badminton racquet and he killed most of them in a few days.

    I have a cabin not too far from you,in Union County,
    I dont have carpenter bees, but I have powder post beetles inside the house
    which i understand can never be killed because they live so deep inside the wood.

  12. Ditto the recommendation for Permachink products. I have used them with good results.

    Log houses absorb moisture in the wet season and expand, and dry out and shrink in the dry season. My parent’s two-story log home (Coastal Oregon) varied 3/4″ in height over the course of a year. Plastic caulk accommodates movement, rigid mortar doesn’t.

    Caulk is meant to fill gaps between logs and seal any cracks in the upward-facing surfaces of logs to prevent water infiltration. If this is done, there shouldn’t be a problem of water pooling. Pro-tip: Cordless electric caulking gun!

    You call it a cabin but it sounds like it might be multistory. If you have solid level ground all around it consider renting a small scissors lift, well worth the cost and easy to operate.

    If the paint is in really poor condition, a pressure washer might be enough to take it off – rent or buy. Handy to use periodically to clean the exterior. Or you can rent a media blaster. Be careful with either one, at full blast you can damage the wood. Start some distance away and close in carefully.

    Once stripped down to bare wood, you can paint or oil. Oiled log houses need re-oiling every 5-10 years, so similar maintenance requirement vs paint. There are insecticide and other additives for oil and paint.

    The price you were quoted is a lot of money so definitely consider doing it yourself. Good luck!

  13. What we did was:

    1) Use LogJam – It comes in calk paste or cement type chinking. Be sure to match the color of your log home stain as they sell a variety. http://www.sashco.com/log-home/wood-seal-chinking/log-jam-chinking/

    2) Stain your logs every year. They say every 2 or 3 years, but if you want. your logs to last we stain every year.

    3) Beside you spray insectacide around the base of the log home and near any wood piles you have for winter fires.

    4) remove your wood piles, that you burn on cold nights, away from your logs.

    5) they sell bee/fly repelant for log homes but you need to put it on before you stain.

  14. Ortho Sevin Dust and water mixture in a pump sprayer works great for yellow jackets and wasps here in Ohio. I don’t know what effect it would have on a boring beetle though. Just tossin’ that out there.

  15. The boring bees are drilling holes to lay eggs for the next generation. I had a problem with this in barns and large sheds in the framing lumber that supports the metal roof. One shot of wasp and hornet spray killed the bees and anything that hatched from the eggs. It also repelled future bees. In future projects, I used a pump-up sprayer with a mixture of Thompson Water seal mixed with diesel fuel, half and half, to spray the lumber before it was put up. It only takes enough to just wet the lumber and not running off. No more bugs or boring bees. This leaves very little residue as it is absorbed into the wood. In my area we have an additional problem. We have very large wood peckers, about the size of a crow, that will come and peck huge holes where the bees bore to get them and the eggs or larva. The wood peckers are considered “endangered” and are protected. They will leave a large hole when done. No bees=no wood peckers. As a side note, we had 10,000 acres of national forest closed to logging to “protect” these birds. The loggers “disturbed” their habitat. All that time, they were flying into my sheds, pecking on the rafters while I sat on the porch drinking coffee. Go figure!

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