This page is a placeholder for a description of the roof and how it interacts with the log gables.
The gable is the triangular part of an end wall that fits up underneath the roof. In many conventional houses, it's hidden on the inside by being the end wall of the attic. Most log houses you see don't have log gable ends. Instead, they have end walls with post and beam framed windows, or a conventional stick frome above the level of the plate logs on the side walls. There's a reason for that -- logs shrink.
In a log house, you will always find an extra space framed in above the windows and doors. This gap is usually filled with compressable insulation, such as fiberglas batting. As logs dry, they shrink. Most of this shrinkage is across the log, i.e. its diameter gets smaller. There is very little shrinkage lengthwise. This is true of wood in general.
Green logs shrink the most, since they have the highest water content, but even standing dead logs will shrink. My house was built using standing dead logs, in a relatively dry climate. The logs had been up for over three years and the roof had been on for over two years when I first measured the height from the ridge log to the floor. A few years later, it had come down two inches.
As the logs in a log house shrink, the height of the walls is reduced. If you have a window sitting in that wall, it will be crushed as the wall shrinks. With proper construction, the air space above the window allows the wall to come down without crushing the window. The construction techniques for this are pretty straight-forward and well-known.
Log gables present a similar problem, only solutions are not so simple. The gable forms a triangle at the end of the house. The dimensions of the triangle determines the slope of the roof, which determines the length of the rafters. Unfortunately, as the logs shrink, two of the dimensions of the triangle get smaller -- the lengths of the two sides supporting the roof. This means the roof no longer fits -- it's too "wide" from peak to plate. As a consequence, you have to build the roof so one edge is movable relative to the log gable ends. I know of two solutions. One, utilized by Alpine Log Homes in Hamilton, Montana, is to basically disconnect the roof from the log ends. I saw this documented in an Architectural Digest some time after our roof was done. I consider this fortunate, as it was the only solution to this problem I have ever read about, and I don't like it. The second solution was one suggested by John Lapka of Lake Mountain Log Homes who put up the logs on my house. This method fixes the roof to the ridge log, but allows for it to slide down along the gable as the gable shrinks down. In essence, it's like a giant vee shaped piece of cardboard fixed only at the vee.
This page last updated on July 11, 2003.