The Rot Doctor


Subject: log home problem
Date: Thu, 27 May 1999

Dear Dr.Rot,
First I must tell you that your web page was the only one to give out useful information. Now I need your advice. I have a 22 year old white pine log home. I had such a bad rot problem on the windward side of the house that I attached a garage to fix the problem. In some spots I could poke a pencil almost through the log. The other end of the house was starting to go down hill and this is were my problem starts. I tried most over the counter wood treatment products and found them useless after 1 year. I then came up with what may be a real stupid solution. I covered some of the logs in 25yr clear silicon caulking. Now I am afraid that I sealed the water in and am not allowing the wood to breathe. Some areas I missed and now there is also weathered coloration in some spots. I would greatly appreciate it if you would please advise me on a possible solution to this problem..
Thanks, Louis G.

Well, the good news is that the silicone probably didn't harm the wood. The wood can still "breathe" through the interior walls, unless you sealed them too. the silicone may have helped to keep more moisture from getting into the wood. Regardless, silicone is a surface treatment, and can be removed. A wire brush or "sandblasting" with crushed walnut shells are the methods that we would look at. Assuming that one of these methods proves successful and practical, the next question is: what do you do once you've removed it? For logs that are in good condition and just need protecting from future rot we suggest applying Clear Penetrating Epoxy Sealer (CPES for short) to the ends of the logs, the cups where the logs cross, and to any cracks, especially on the top half of the log. Anywhere that water can collect and soak into the wood rather than run off. This will greatly reduce the ability of water to get into the log. If you can keep the moisture content of the logs below 20%, the rot fungi have a hard time reproducing.

For logs where the rot has already established itself, you need to soak CPES into the interior of the log. For your "push a pencil through" logs, you are better off cutting the face off the log and filling in the voids with scrap lumber. Packed in with Fill-It epoxy putty, and everything first soaked with CPES, of course. Finally, you can glue the log face back on.

We are talking about a significant amount of CPES, so if you are interested, I'd suggest buying it in volume. It is available in 100 gal. orders (two 50 gal. drums) for a large savings in cost per gallon. This would not be cheap, but would be economical compared to the cost of log replacement.

Further questions? Anything I wasn't clear on? Want a more detailed description of any of the above procedures? Let me know and I'll try to answer.