You are now ready to start erection of the walls. Make frequent and careful use of the plumb line and spirit level in this work. Without constant checking the walls have a way of going off at odd tangents.
The simplest and least difficult style of fitting logs is the “saddle and notch,” in which the logs are given a rough notch and laid together without special fitting or trimming. The spaces are later caulked with oakum. While this is the simplest method, it is the poorest from the standpoint of weather tightness.
Four methods of notching logs.
Another and better method is the same as above except that the notches are so carefully cut that the logs fit closely and must be hewn down along two sides to provide neatly joined surfaces. This also will require some caulking but not as much. It is customary to lay a strip of oakum between all logs, regardless of the style of fitting.
Cupped Logs Fit Snugly
A third method is to use “cupped” logs. The same saddle and notch is used at the corners, but the upper log has a concaved channel cut its entire length, which makes it fit down snugly over the lower log. The cup may be cut with curved-blade adz or with a heavy gouge. This is more work but well worth it. Cut each cup to fit its individual lower log, marking the cup with a pair of dividers to insure a close fit. When you have a perfect cup (which means rolling the log into position several times to try its fit) lay a layer of heavy oakum along the lower log, roll the upper into its final position and spike it down.
The finest method of all is a further refinement of the cupped log style. The upper log is cupped as above but, instead of a simple notch at the end, the upper log is cut out exactly to fit down over the lower tightly, while the lower is not notched at all. Oakum is strung the same as for other methods and laid in at the corners. In the best work of this type no oakum should show. Although the pioneers put their cabins together without nails, they did so because they had no nails to use. To be safe, spike all logs together with 12-inch spikes—the largest size made.
Before you get the walls too high, give a thought to windows and doors. There are two ways of taking care of them. The extravagant way, much used by our forefathers, was to build with logs to the top line of the proposed opening and then cut out a hole the required size. An easier—and less wasteful—way, if you are doing your own work, is to use short logs, leaving a more or less rectangular opening. Then nail a couple of straight boards where your frames should come and saw off the rough projecting log ends as illustrated above.
