Log rot – Replace log or cover it with siding?

Here’s a question we receive periodically: “My log home has some rot in several logs on a couple of the walls. We don’t really want to deal with the rot so we are considering putting some sort of log siding over them to cover them up. Is that an adequate solution?”

Another common situation we come across is when someone purchases a log home or cabin and they are aware that the previous owner has put some siding up on one or more of the log walls. They call us wondering what they should do. After seeing this so called “solution” used on numerous log buildings over the past 40 years, we have some thoughts on the subject.

One good reason NOT to use siding or other methods of covering the rotten logs rather than replacing them with true whole or half logs is that the look will not be the same. It can really diminish the overall aesthetics and value of a log building. Using log siding can look like you tried to match the logs, but really it is only a “sort-of-tried”! It just doesn’t look the same.

Most log siding is usually 1.5 – 2″ thick. So if the plan is to remove some of the rot and fit the log siding over that area, you typically cannot remove all of the rotted wood because all that you have to put back in its place is siding that is only 1.5 – 2” thick. Often there is considerably more than an inch or two of rot somewhere in the log so you are not actually removing all of the deteriorated wood, which means there is still a source of food for certain insects such as carpenter ants or powder post beetles to feed on.

Here is another thing to consider. Most log siding is not made of cedar. Our replacement logs are dry western cedar and are inherently resistant to rot. That means that once we replace a rotten log with one of our cedar logs, we are confident that it will not rot again. We have certainly seen examples where pine siding was installed to cover rotten logs and the siding itself rotted.

In many situations, putting siding over the affected logs does not alleviate the environmental pressures that caused the original logs to rot in the first place, i.e. moisture and sun. So it stands to reason that with the same pressures present, the new pine siding will eventually rot too.

This is the main reason we use cedar logs for our repair work. We firmly believe in doing the repair once and doing it right.