Traditional log buildings in North America
Oct 1, 2008 Log Cabin History
Log cabins were built from logs laid horizontally and interlocked on the ends with notches (British English cog joints). Some log cabins were built without notches and simply nailed together, but this was not as structurally sound. Modern building methods allow this shortcut.The most important aspect of cabin building is the site upon which the cabin was built. Site selection was aimed at providing the cabin inhabitants with both sunlight and drainage to make them better able to cope with the rigors of frontier life.
photo credit: Let Ideas Compete Proper site selection also placed the home in a location best suited to manage the farm or ranch. When the first pioneers built cabins, they were able to “cherry pick” the best logs for cabins. These would be old growth trees with few limbs (knots) and be straight with little taper. Logs of this type did not need to be hewed to fit well together. Careful notching minimized the size of the gap between the logs and reduced the amount of chinking (sticks or rocks) or daubing (mud) needed to fill the gap. The length of one log was generally the length of one wall, although this was not a limitation for most good cabin builders.
Decisions had to be made about the type of cabin. Styles varied greatly from one part of the US to another: the size of the cabin, the number of stories, type of roof, the orientation of doors and windows all needed to be taken into account when the cabin design was being made. In addition, the source of the logs, the source of stone and the available labor either human or animal had to be considered. If timber sources were further away from the site, the cabin size might be limited.
Cabin corners were often set on large rocks; if the cabin was large, other stones were used at other points along the sill (bottom log). Thresholds, since they were usually cut into the sill, were supported with rock as well. These stones are found below the corners of many 19th century cabins as they are restored. Cabins were set on foundations to keep them out of damp soil but also to allow for storage or cellars to be constructed below the cabin. Cabins with earth floors had no need for foundations.g
Cabins were constructed using a variety of notches. Notches can vary within ethnic groups as well as between them. Notches often varied on a single building, so their styles were not conclusive.
Log cabins were constructed with either a purlin roof structure or a rafter roof structure. A purlin roof consists of horizontal logs that are notched into the gable-wall logs. The latter are progressively shortened to form the characteristic triangular gable end. The steepness of the roof was determined by the reduction in size of each gable-wall log as well as the total number of gable-wall logs. Flatter roofed cabins might have had only 2 or 3 gable-wall logs while steeply pitched roofs might have had as many gable-wall logs as a full story. Issues related to eave overhang and a porch also influenced the layout of the cabin.
The decision about roof type often was based on the material for roofing. Milled lumber was usually the most popular choice for rafter roofs in the areas where it was available. These roofs typify many log cabins built in the 20th century, having full-cut 2×4 rafters covered with skip sheeting and cedar shingles. The purlin roofs found in rural settings and locations, where milled lumber was not available, often were covered with long hand-split shingles.
Tags: designs, traditional log homes
