For the log-type frame, copper or galvanized steel flashing should be fastened to the bottom of the cut in the top log, leaving the lower edge of the flashing free to slide on the face of the log head jamb. As the wall settles, the bottom of the flashing can be trimmed off if too much of the face of the head jamb is covered. This makes a weathertight joint and protects the insulating material with which the shrinkage space has been filled. See [figure 17], Head section.
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Figure 19.—Framing log purlins for shakes.