The Rot Doctor


Subject: Log Home question
Date: Sun, 11 Apr 1999

Hello Rot Doctor. I am enjoying your website, and have a question: We just bought a 23 year old log home in New Hampshire. The logs were probably originally pressure treated, with what I don't know. (Penta?) The previous owner used CWF Clear Wood Finish, by Flood, applied every few years. The logs are not rotten, just very dirty on the North and East side-where the weather comes from-from soil blowing off of the crop field on that side. On the South and West side I believe exposure to sun has caused the logs to weather and open up a lot, along the grain, so that the surface is like corduroy with the cracks 1/2 to 1 inch deep. Beneath this surface problem the wood is sound, but not protected from the elements, and most of these cracks are upward facing. The color has gone grayish and there are some black specs (mildew?) on this side.

I was wondering if your epoxy products would be recommended for this side, as well as all of the ends of the logs and around all of the windows. Do you recommend washing the logs first, and if so with what? I've found suggestions of bleach, H2O2, and oxalic acid solutions.

We plan to seal the outside of the home by stuffing closed cell foam backer rod between the logs and then caulking over it. It is not a chink-type home.

Sincerely, Heidi in New Hampshire


Well, our CPES (Clear Penetrating Epoxy Sealer) will do more to prolong the life of your wood than anything on the market. If CPES were free you could profitably coat the entire exterior with it. But of course it's not free....

Your suggestions make a great deal of sense. Certainly the upward facing cracks should have CPES applied inside. I would prep them by brushing them out -- no water! Never use water on wood that is going to be CPES-treated. While I'm on the subject, never use pressure water AT ALL on a log home if you can avoid it. If you need to wash the logs (use TSP -- trisodium phosphate -- and water -- no bleach!) do it by hand and then rinse by just allowing the water to run down the surface; you don't want it squirted in between the logs. The best solution of all is to have the logs pressure-blasted with walnut shell or corn-cob material -- no water and very clean. Then apply your finish.

But back to the permanent protection with CPES: Yes, it can be profitably applied to log ends wherever you believe they are exposed to the weather. If the wood is reasonably dry the ends will soak up and amazing amount of CPES, which is good because the wood is then highly resistant to rot or bacterial degradation. Your caulking plan sounds fine. Before you caulk, though, examine the to-be-caulked area and if you see any signs of soft or punky wood then apply CPES. This will significantly help resist rot from developing behind the new caulking.

Beyond all this, keep your eye on the exterior wood and wherever you see signs of rot or deterioration, apply CPES. CPES will keep indefinitely in the cans (unmixed, of course) if the lids are on tight and it is kept from freezing. To accomplish what you are proposing I would guess you'd need somewhere between 2 and 4 gallons. It all depends on how much the wood absorbs, and you do want to give the wood all it will conveniently accept. We do ship daily so if additional it needed you can order immediately.

If you have more questions, come back. We want to be as helpful as we can.