April 25, 2016
COMBATING WEATHER DAMAGE
Up to now, our attention has been focused on methods for controlling fungi and insects. The other area of concern is weather. The four weather factors (sunlight, water, temperature, abrasion) also play an important role in creating the necessary environment for fungal growth. By protecting your log home against the adverse conditions of weather, you will also be employing the fundamental maintenance strategy against fungi, which is to reduce the effects of moisture. Many treatments have been proposed to protect wood against weathering. Of all the various coatings and treatments available, paints containing UV absorbing or screening pigments provide the most protection to wood. However, most people who choose to purchase a log home don’t wish to paint their logs and hide the natural beauty of the wood. Leaving aside the artificial appearance of a painted log, there is a more serious problem with using paint on a log structure. It has to do with the mass of the logs and the moisture contained within them. Because paint is designed to encapsulate and totally seal the wood fibers from the elements, it can and will trap the moisture that is naturally trying to escape from within the log to the outside environment, This is especially true with new, greener logs. This condition can lead to wood rot and a whole host of moisture-related coating problems. Kiln-dried clapboard siding and other conventional types of wood siding don’t usually encounter these particular kinds of problems because the moisture within the wood section has been sufficiently reduced. Protecting Your Log Home Exterior Against Ultraviolet Radiation(sunlight) By itself, UV causes wood to darken and gray and over a long period of time will break down the structural components of the wood (about a 1/4 inch per century). However, UV rarely works alone but in combination with moisture, fungi, and other factors that together accelerate the destruction of wood. To protect wood from UV requires shielding the surface with a coating that contains UV blockers. The longest lasting and most durable UV blockers are found in special types of pigments. Consequently, the degree of UV protection provided by a wood coating is largely in proportion to the amount and type of pigments used. Regrettably, stains with higher levels of pigments ruin the natural look of the log by creating an artificial painted appearance. Significant improvements have been made with natural wood finishes but it is unlikely that they will ever achieve the UV protection of highly pigmented solid colors. However, new technology and formulating breakthroughs have led to improved UV performance and increased service life of transparent and semi-transparent stains, especially several developed for the Log Home Industry. Unfortunately, UV will degrade any type of protective wood coating and is a major reason why additional applications of stain will be required periodically. This sections content was provided by The Continental Products Company.