Door and window jambs should be framed just like the corners except that
only the back should be grooved. The door side, or face, may be rabbeted
or left smooth so that a separate wood door stop may be nailed in place.
If the logs are reasonably dry, from 3 to 4 inches should be left at each
corner for settlement due to shrinkage; otherwise, more or less space
should be allowed, as conditions require. In about 6 months the cap log
will come down and close this gap. Similar provisions should be made for
settlement over door and window openings.