Here is a related question from our previous posting:
Question: I need to get wood-boring beetles and carpenter bees stopped. No serious structural damage yet but the insect problem needs to be addressed. I am the original owner of the home. It was built in 1985 out of southern yellow pine. It was a kit supplied by Real Log Homes out of North Carolina. It was last cob-blasted, borated and sealed in 2004. Borate applied at that time did not stop insects. Need help to get insect damage stopped and house resealed.
Answer: What we know about carpenter bees and powder post beetles is that they feed on decaying wood. Therefore, they often are a sign that the logs are retaining moisture and that there is some rot. Borate treatment is not a guarantee against these insects. It isn’t a pesticide but more of a treatment for the logs to raise the PH level of the wood to the point where the rot organism is impeded, and subsequently the bugs are less able to attack it. Click here for more information about insects in log homes.
Sometimes it works to squirt some concentrated borate solution (Bora-Care) into the holes themselves. Other times, it is necessary to get an exterminator in to knock back the population of the pests so you can get ahead of them. Click here for more information about borate treatments.
My first concern is that you may have some rot issues. I would be curious to know what type of finish you have on at this time. Some finishes build up a “shell” over time that does not allow the logs to breath. Moisture gets trapped between the logs and the finish and rot can take hold.
Another situation we have seen with pine logs is that sometimes they were cut when they were standing dead trees. These tend to rot from the middle out and the rot is not readily evident from the outside of the log until it has advanced. I am not sure if this is the same type of log you have but this information may be helpful.