Civil Engineering Reference
In-Depth Information
Decorative diamond notches on a 1763 silver-
smith's cabin in Leesburg, Virginia. The notch
is actually a functional V-notch with the ends
dressed to the diamond shape for appearance.
The V-notch in these oak logs was typical
along the eastern seaboard. Later in this
area and farther west, the half-dovetail
notch became common.
This is the half-dovetail notch or chamfer and
notch found on most American hewn-log
cabins. This example in oak is from the Ozark
Mountain area of Arkansas.
This half-dovetail notch pulls the corners tighter
together both ways with the weight from above, which
some other notches do not. The V-notch and com-
pound-angle dovetail are the other two best choices.
These also allow rainwater to drain out, which helps
prevent rotting. Wide eaves help here too, a non-
pioneer practice that keeps making more sense as
time goes on.
Notching should follow a pattern based on a set
angle, and a set amount of wood left, not wood taken
out. So notch a swelled butt end deeper than the thin-
ner top end, but keep the same angle. Cut yourself a
pattern to use on the hewn logs. We use a two-inch rise
in a six-inch thickness. Make sure the pattern is laid
pointing straight to the other end of the log, or curves,
kinks, and flaring ends will throw you. This is where a
snapped chalk line down the centerline of the log can
help you. It's possible to use a square and template to
get the notch nearly perfect. This takes about as much
Notching
You'll read about V-notching, saddle notching (round
logs), full-dovetail notching, tenon (square) notching,
half-dovetail (also called dovetail) notching, and
probably some others. The traditional log builder used
the chamfer and notch, or half-dovetail notch, which
is simply a vertical cut on the underside of the log to a
depth that leaves the desired space for chinking, plus
an angle cut toward the end. This is the notch. The
chamfer is the sloping cut on top of the log that lets
the next cross-log notch fit over it.
Our own Missouri cabin had been scrambled at
least once before, in rebuilding, and several of the logs
and their notchings were upside down. And there
were some full dovetails among the halves. We decided
to leave them that way instead of reshaping the brit-
tle old wood. The cedar logs I added were all half-
dovetail, right-side up.
