The Restoration Process Consists of 4 Basic Elements: Surface Preparation, Preserving, Staining and Sealing
Article Credit: Jim Renfroe
Builders and designers of log homes generally do a good job of anticipating shrinkage and settling. They offer help in construction techniques that are unique to log homes, like scribing drywall around logs, running electrical and plumbing chases. But when it comes to initial and ongoing care and maintenance of log homes, there is more bad information given than good.
The initial wood treatment is often a coating that like paint is designed for adhesion to the wood and offers little or no protection to the wood below the surface. These film building coatings can cause a multitude of problems until they are removed, or wear off. Many films are very hard, so when the logs move, the film cracks. Water gets between the film and the logs and mildew begins. The film becomes like a greenhouse, incubating the fungus and trapping water inside the logs. This process has contributed to wood rot bad enough to necessitate log replacement in as little as 10 years.
It boils down to this:
Once you cut a tree down or it dies, you cut off its abilities to defend itself against its natural enemies. Mother Nature’s job is to return all things to the earth, including dead trees. If dead trees become house logs, you have to be very proactive in your approach to treatment. The best treatments are borates because they have no smell or color and are virtually nontoxic to mammals. They can be applied by pressure treatment, dipping, by brush or spray, or inserted internally using solid borate rods. CCA is another highly effective wood preservative that can only be applied by pressure treatment.
Part I – Wood Preparation:
All four steps of the restoration process are important but surface preparation is the most involved, most critical and often the most overlooked. Lack of proper surface preparation is like not washing a car before you wax it. House logs need to be clean, bare and dry before you go too far, otherwise, you will end up doing it all over again because the new finish didn’t penetrate or in some cases adhere. Also, the best time to tackle a project like this is when the temperatures are above 60 degrees. Not only will the job go faster because of reduced drying times, but cleaners, strippers, stains and preservatives all seem to accomplish their respective tasks more efficiently in warmer temperatures. However, the process can be done in much cooler weather, it just takes longer.
Surface Preparation and Stripping.
Striping is not always necessary. As a rule of thumb, there are four circumstances that dictate when stripping is necessary: When there is any type of film or coating on the wood, When there’s a build-up of old finishes When there is any area of the house where the old finish is peeling or cracking When there is a glossy finish on the house If the old finish is acrylic or latex, make sure the stripper you use is designed to remove it. Most strippers work well on oil-based stains and paints, but the latex chemistry requires a different stripper. If, however the house has had penetrating finishes applied to it or it has never had anything applied to it, or if a gentle breeze blows bits of the finish away, you can skip the stripping process and pressure-wash instead. Usually, a log home will collect dirt on the top side of the logs and that can be easily rinsed away. A home will usually have a line of discoloration mid-log on the exposed areas and along the bottom few logs where rain water from the roof hits the ground or deck and splashes back. Corners and exposed purlins often darken or turn black due to mildew or mold growth. The damaging effects of the sun manifests itself in gray wood.
Cleaning the logs
Bleach and water with a little detergent has been a long-standing recommendation for cleaning dirty wood. It works pretty good, it’s pretty fast and it’s cheap. However, there are a few drawbacks to bleaching wood. One, bleach can destroy the cellulose in the wood when left on the surface too long. Two, some researchers tell me that bleach inhibits the wood’s ability to hold a finish. Also, while the wood will get significantly cleaner, it often still looks gray or an unnatural washed out color. The other drawback of homemade bleach solutions is they are very difficult to completely rinse from the wood. Remember the last time you got bleach on your hands? It’s hard to rinse off and wood soaks up a lot more than your hands will. Also, household bleach only remains active for about 15 minutes once it’s mixed with water, so you have to use it quickly. However, if you insist on making your own bleach solutions, use it quickly, rinse it immediately after the job is done, rinse it well, then rinse it again.
Prepared Cleaning Solutions
When you buy a prepared wood solution from your friendly neighborhood mass merchandiser, look for the active ingredient of Sodium Percarbonate, Sodium Hypochlorite, or Calcium Hypochlorite. These are all bleaches. However, most store bought products contain buffers to ease the wood damage and surfactants to help wet the wood quicker and allow it to rinse off easier. Also, when spraying bleach on a wall, start from the bottom and work your way up. This will minimize streaks, which are difficult to remove. If the wood is just discolored, and has no significant areas of mildew, look for a wood cleaner containing Oxalic Acid. This is a mild acid that restores much of the wood’s original color. It is especially good for redwood and cedar, which darken pretty quickly due to extractive bleeding. Oxalic acid based wood cleaners will also remove gray weathered stains, metal or nail stains as well as water stains.
Pressure washing is a very efficient way to rinse off a stripper or wood cleaner. However, you must exercise extreme caution when using a pressure washer or you will cause damage to the logs and possibly force water through the logs to the inside of the home. Here are a few pointers for pressure washing: Use no more than 2500 psi Use a pressure washer that delivers at least 3 gallons per minute, preferably 4 gpm. Keep the tip of the spray wand at least 12 inches from the wood surface. Do not hold the spray in one place. Keep it moving back and forth along the grain. Start the spray with the wand pointed away from the wood and move it onto the log. Never point the spray pattern at your skin. It will puncture skin and mandate a hospital visit. Be careful on ladders with a pressure washer. The force may throw you off balance. Do not concentrate the spray in corners, around doors or windows and between logs. Move quickly past those areas. Always have someone stationed inside the house with towels and plastic prepared to catch any water coming into the home.
In next weeks blog we will continue with Part II (Preserving) of expert Jim Renfroe’s advice on the Log home restoration process. We at 888 Log Guys are excited to share this information with you and help answer any questions you may have and assist you with your restoration project!