Repairing Damaged Logs in Belguim
Enclosed I do send you some pictures of my wooden holiday home at which some logs on the stone basement are seriously being damaged by, I presume, wood worms or other insects. Can you please advice me what to do ?
Thanks and kind regards,
Johan Hosselaer Belgium
Dear Mr. Hosselaer:
- After viewing the photos of your home I believe that the damage to your logs and log home has to do with rot and not insects.
- If the damage was caused by insects, they would most likely be termites which work on wood that is located in close proximity to the soil surface. The termites bring up moisture to the wood via tubes/tunnels and then devour the wood. Your logs are located high above the soil surface, on a raised foundation which contains a garage/garage door. Thus termites would have to climb some distance to get to your logs. This is not likely.
- The other insect pest could be various wood boring forest insects. However, forest insects normally attack trees that are dying or recently dead and still have some moisture in the tree or in the wood. They would then lay eggs in the logs which hatch and turn into larvae which bore through the wood. Eventually the larvae turn into an adult and fly away. Your home has been built for a number of years and thus the logs are dry. This is not a good environment for forest insects to lay eggs and live as wood eating larvae. If larvae have invested a log home or any old log for that matter you can hear there loud boring sounds if you are sitting nearby.
- I see from you photos that there are a couple of flaws in the construction/design pf your log home. First of all you need to have rain gutters installed on the roof so that the rain water and snow melt does not run off and hit the deck and blow against the logs of your home. These gutters should be mated with down spouts extending down to the ground level and then extensions placed on these spouts to take this water away from the home.
- How do you determine which logs contain rot? The best way is to use an ice pick or some tool which is similar. Examine the bottom logs first as these are the ones that most likely contain rot. Shove the ice pick straight into the log. If it is rotten, the ice pick will go in easily once it has penetrated the hard, outer shell of the log. Remember, logs rot from the inside out. When they become wet, the outside of the log dries fairly quickly; the inside remains wet (30 to 60%) for quite sometime and thus this wet, interior, area is perfect for decay to proliferate. I would say that the bottom two or possibly three courses of logs could contain some rot.
- When the home was built, the deck was installed so that the decking material was placed right up against the logs. This is a no-no!! The rain and snow melt runs off the roof, hits the deck in large amounts and runs back against the logs. The logs then reach a moisture content of between 30 to 60% and this precipitates rot. I found this a common mistake in log home construction in the USA as well. When the water hits the logs, the water will “wick” up higher into the other logs.
- Remedy?? First of all install the rain gutters and down spouts. If you do not do this, all will be lost. Then replace any damaged/rotten logs. Treat these damaged areas with a wood preservative. I do not know what is available in Belgium, but in the USA we can only legally use a water-soluble, borate compound which is considered safe for the general public. The drawback is that it is water soluble so excessive rain water and wetting can also leach the preservative from the logs and render it useless. If you can use Penta or CCA, then this can be used in lieu of the borate compound. All chemicals should be used sparingly so that it does not become a problem when someone comes in contact with it.
- After the logs have been installed and the old, rotten ones removed, install flashing between the logs and the wood decking. This metal flashing should protrude up above the decking about 6 to 8 cm. and about the same amount below the top of the deck. It should be tacked at the top of the flashing and a silicone caulk also applied at this point as well, to keep blowing rain from getting behind the flashing. The flashing can be painted the color of the logs to make it blend into the look of the home and not be unsightly. Thus if a large amount of blowing rain washes over the deck, the metal flashing will keep the logs from getting saturated with moisture once again. Remember, dry wood does not rot.
- It seems that your log home has been well maintained, with an exterior finish, and this is great. But the finish will not keep rain and moisture from getting through to the logs under severe or prolonged conditions. The best remedy against rot is to keep the logs dry. This is why we recommend 5-ft overhangs on the gable ends and a maximum amount that can be attained at the rafter tails. Keep it dry!!
- If you have any further questions, please feel free to contact me at any time. This service is free so don’t be afraid to ask questions. Treat me like a relative; a relative who always is willing to give plenty of free advice!!
- Oh yes, I have traveled through Belgium many times to visit the battlefields of WWI and WWII. Need I say that I love it. I remember the lovely little village of Malmedy, near Bastogne, which suffered so much at the hands of the Germans and also U.S. bomber aircraft. And besides the countryside, I also love the Belgium beer. Keep in touch and thank you for having faith in our expertise in wood and log construction.
Clyde Cremer Forester and Log Home Manufacturer
Dear Mr Clyde Cremer,
It was great and surprising at the same time to get such valuable and tailor-made feedback and advice from over the ocean.
Together with my brother in law we will have an in-depth look at your comments and check whether we can apply your remedies in practice.
Fine to hear that you're familiar with our country. In fact our 'chalet' is situated at not more than 25 kilometers from Malmedy in the Belgian 'Ardennes'.
If you allow, we'd like to send you some more detailed pictures so that you can get a more precise look of our wood-problems.
Anyhow, thanks a lot and warm regards from some new Belgian friends,
Johan Hosselaer Ignace De Nil