Roofs may be framed in several ways, depending upon the kind of material available and the appearance desired. The framing for a shingle roof, whether of sawed material or round poles, is done in the same way as that of a frame building. The top log on the wall may be cut with a flat seat for the rafters to rest upon, as at Y, in [figure 18, A] or notched out to receive them as at Z in [figure 18, B]. The gable ends may be run up with the logs, which is preferable for architectural appearance, or framed like the gables of a frame structure, and then covered with wood siding, shingles, or shakes ([fig. 19]).
The shingles may be laid over sheathing boards in the usual manner or on shingle strips placed across the roof rafters, parallel with the ridge and exactly spaced to receive them, commonly known as “barn-fashion.”
The particular method to be followed in framing the eaves depends largely upon their projection. Where the effect of a considerable overhang is desired, an eave purlin log may be used to support the projecting shakes as shown in [figure 19, A]. To support 30- to 36-inch long shakes having a 6-inch lap, the log purlins should be spaced at approximately 24-inch intervals, as in [figure 19]. In regions of heavy snows, the eave log may be placed slightly forward to help support the overhang, or an additional eave log may be placed in position, as shown in [figure 19, B]. The gable logs should be run up at the same time as the roof logs, and both rigidly framed together.
Figure 20.—Splitting shakes with the froe.
It is often desirable to use hand-split shakes for the roof covering. These are usually made from cedar, but may be of any straight-grained wood, free from knots, which splits easily. First, the logs are cut in lengths of 30 to 36 inches and then the shakes are split off with a tool called a froe ([fig. 20]).