One of the first questions people ask about log homes is How Much Termite Damage Do They Get? Well, rest assured: log homes are no more susceptible to termites than a traditional framed house. In some ways, it would be easier to spot possible infestation: in a stick-framed house, you could have an problem for years without even knowing it. The termites would be hidden behind your sheetrock, happily gnawing away at structural members, and would attack your walls from the inside-out. With a log, they would most likely start on the outside and work their way in, leaving an obvious trail of sawdust or mud foraging tubes.
Termites thrive in a damp environment; they dehydrate when exposed to the air for too long. If your logs are kept dry, they won’t be a tempting target for wood-boring insects. On the other hand, if you have a spot where a gutter is leaking onto the logs, or your door frame leaks, watch out! That damp spot is the point of entry for insects and wood rot. Also, keep your air conditioner from dripping near the foundation; this is another potential trouble source.
In new construction, there are some measures you can take to reduce the risk of termite damage. First of all, make sure your contractor does not bury any wooden construction debris under the topsoil. This is very common on job sites, and the decomposing wood creates a great environment for new termite colonies. Secondly, make sure they install a termite shield below the sill plate; this is a bent piece of metal that creates a barrier between the foundation and the wooden sill. Many townships require this by code.
Before you apply the stain, it would be wise to spray the logs with a borate treatment; when added to water, this powdered insecticide is designed to soak into the logs and protect them against insects and wood rot. After the borate treatment has dried (and before the rain washes it off), apply your stain which is toxic and will also protect your logs from insects. To be extra sure, there are additives you can add to the stain that contain insecticides.
Carpenter bees do not like to chew through treated, painted, or stained wood and will probably find more tasty surfaces to attack. Keep an eye on your porches and fascia boards; after a few years, when the stain no longer looks fresh, the bees may revisit your house and start making those perfectly round 1/2″ holes. Luckily, they are easy to treat and once you spray and plug those holes, that particular bee should be taken care of.
Caulking between the log courses is another good way to seal out the insects. I’ve actually watched a fly drag a tiny leaf into a small split in our log ends. You just don’t know what critter wants to live in your logs. Also, do not stack firewood against your house. Chances are very good the cured wood already has insects in it, and you don’t want to transfer them to your pristine logs.
The most important thing to do is make an occasional investigation of your corners, eaves, window frames, foundation. Many infestations are easily dealt with if caught early enough. Don’t assume your house will take care of itself; you, the owner, will be the first line of defense.