SQUARED LOGS
Squared logs and vertical flat siding are easier to maintain since the sun hits the logs at the same angle, and the UV light is evenly distributed over the entire surface. In addition, the flat vertical surfaces cannot accumulate snow and ice and even upward facing checks are not as prone to rainwater entering the logs. Although squared logs are subject to the same weathering parameters as round logs, and since the weathering is mostly uniform over the entire exposed surface, maintenance is easier to accomplish without worrying about lap marks and color differentiation.
LOG SIDING
Round log siding probably presents the greatest challenge to forestalling the effects of weathering. Typically used in high exposure locations such as dormers and gable ends, in addition to suffering the same weathering characteristics as round logs, log siding has some features which makes it even more difficult to protect from the effects of the weather. Siding is often manufactured from lower quality wood than logs, frequently using green wood. This makes it more susceptible to twisting, warping and cracking. Since siding does not have the high thermal mass of full logs, during the summer months their temperature can range from 80ºF to 160ºF - or higher - during the course of one day. This puts a lot of mechanical stress on both the siding and its finish system resulting in small fissures forming on the surface. Rainwater can then enter these fissures and get behind the finish.
FISSURING OF LOG SIDING
Round log siding is typically milled quite smooth. The extreme smoothness presents a challenge applying the proper thickness of pigmented film necessary for adequate protection of the underlying wood. Smooth log siding should be coarse sanded or pressure washed using Wood ReNew™ before the application of the pigmented stain.
There are two basic ways to combat the effects of weathering. The most effective method is to keep log walls and siding in the shade by extending roof overhangs or constructing roofed porches around the home. The next best way is to apply a high quality finish system like Lifeline™ Ultra-7 and Advance Topcoat. But the overall performance of even the best finish system is dependent upon proper surface preparation and application technique. Avoiding the use of chlorine bleach and back-brushing all coats of finish to assure adequate film thickness is crucial for long term protection of the wood.