Log Restoration Sheds Light on Construction
The purpose of this article is to share what I have learned through years of restoring log homes, and how those lessons can help people who build new log homes.
We all know that log homes require some annual maintenance, and sometimes the maintenance is more involved, depending upon the climate. For instance, in Western Washington we have considerably more rainfall than many other states. This demands more attention to the maintenance of a log home—climate can quickly damage unprotected logs. I restored a log home in Hawaii where the climate is hot and humid and the logs on this particular log home were so covered with black mold that, in some areas, it had the appearance of having caught fire.
Deep roof overhangs are key to keeping logs in good condition. Exposed gable ends with 16 inch or less overhangs are going to have problems down the road, especially if those gables and dormers are facing south. If there is not sufficient protection from the elements, you will have early failure and, if this is not taken care of, these areas can rot. I would suggest to anyone building a log home to have at least a 3-foot overhang around the house.
This past summer I restored a log home that was on a bluff overlooking the water in an area with high winds. They had 6 foot roof overhangs in some areas and had done minimal maintenance over 10 years. The stain had failed and had to be removed (especially on the side facing the water) but in some areas, where the logs had been protected, they looked good. I would say that the overhangs played a big part in the protection of these logs.
Roof purlins are vulnerable if they are extended past the fascia boards or drip edge. This problem occurs due to exposure to the elements unless, during his annual maintenance, the owner is willing to climb up to each purlin to check and treat. I would suggest that all purlins be cut back behind the fascia boards and that Impel Rods be inserted from the top—before the soffit material is installed to hide the holes were the Impel Rods were installed. Installed Impel Rods will remain dormant until moisture wicks in from the unprotected butt end of the log to start the diffusion. Impel Rods, once diffused, will help protect the purlins from rot and insects.
Joists & Balconies
Extending floor joists out for deck support is not a good idea. I have worked on several decks where the deck supports have broken off the house, causing the deck to collapse. In most cases, this is caused by the deck supports being planed flat so the decking material can be installed. The problem is that, once the deck supports are planed flat, water is trapped between the decking material and deck supports. Another problem is checks in the joists that trap moisture in the heartwood, and yes, heartwood does rot. By the time you have identified the rot, you could be into some costly repairs.
If the rot is minimal and has not traveled past the log wall, and at least 70% of the log joist is still solid, then the rot can be dug out and these areas filled with epoxies. If the rot is extensive and has traveled beyond the log wall, you will have interior second-floor structural issues that are expensive to repair. Before the new decking material is installed—I would treat the top portion on the repaired log with copper napthenate, use metal flashing, and then install the decking material.
Restoring failed finishes and stains is probably 60% of our work. This is interesting because I have worked on log homes that have had very little maintenance, as mentioned above, and others that are as new as three years. I have noticed that newer log homes experience finish failure that, in most cases, is due to improper prep work and/or using inappropriate or inexpensive log home finishes.
Exterior finish is more critical than interior finish for the obvious reason of exposure. Climate in your area is also important when considering a finish. I personally test the stains from many manufacturers. I use samples of different wood species, prep them as I would in restoring a log home, document the date, time, and weather condition for each sample. Then I apply the stain and wait up to a year to see my results. I usually do this in the fall when the weather changes. I am currently using an oil-based penetrating finish, and I am testing a waterborne finish that I am considering.
What you want, no matter where you live, is a penetrating finish. Stay away from film formers. Logs have to be able to allow water vapor to go through the finish. If there is a film-former stain on the house, the water vapor is going to get trapped. In time: the moisture from the trapped vapor will pop (separate) the finish from the log, or will cause rot, or both. Film-formers may also blister from ultraviolet exposure.
An old finish can be removed by: chemical strippers, cob blasting, or CO2 blasting. I have used cob blasting for several years with excellent results. I have blasted interiors and exteriors. The downside to cob blasting is the mess it makes. Even with tarps it is impossible to catch all of the cob media. We tell customers that we can recover around 80% of the blasting material.
Cob blasting does raise the grain; though if the operator knows what he’s doing it will be minimal. Furthermore, we carefully sand with electric sanders to knock down any raised grain. How much of the grain will be raised is based on how aggressive you need to be and what your taking off. As mentioned above it has a lot to do with the experience of the operater. The sanders that I use are Porta-Cable, random orbital, model number 7336. The sanding pads should be hook and loop using Mirka brand 60 grit paper. If cob blasting cannot be used, chemicals do a great job. The chemicals used are Sodium Hydroxide as a stripper (Ph 13). Oxalic Acid (Ph 0 to 3) is used after the stripping process as a neutralizer and brightener. Both of these chemicals are dangerous and should be used with extreme caution. There are other strippers on the market that are safer however most of them need a dwell time of 24 hours and they must stay wet.
Several years ago in Washington State, a stain manufacture was sued because their stain never fully dried after application, and this caused severe mold problems. I saw this failed stain on log homes and it got so bad there were mushrooms growing on them. But because the stain hadn’t dried it was impossible to remove using the cob blasting method. The cob blasting would basically just push it around instead of removing it from the log surface.
Another method of finish removal is dry ice (CO2) blasting which is similar to cob blasting, but is an excellent way to remove tacky finishes. This process uses dry ice pellets that resemble grains of rice and has a temperature of minus 110 Fahrenheit. When the dry ice hits the surface, it causes a process called thermo-shock. As the substrate temperature decreases, it becomes brittle, enabling the dry-ice particle to break up the failed stain. The beauty of it all is that the CO2 dissipates into the gas carbon dioxide so there is very little blast-residue to clean up—only the failed finish. Dry ice works especially well inside log homes since the cleanup is minimal.
Bill Finley is the principal of West Coast Restoration LLC, a log home restoration business in Bellingham Washington. Contact information is available at www.westcoastrestoration.com
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