Roofing
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 like bark. Milled lumber was usually the most popular choice for rafter roofs in areas where it was available. These roofs typify many log cabins built in the 20th century, having full-cut 2×4 rafters covered with pine 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.
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