Log Cabin Logs - Shapes, Connections and Corners

Logs for a log cabin can be milled or handcrafted. Hand crafted logs are unique and vary in size. Due to their hand crafting, they are more expensive but produce a more natural look. There are also half logs which are used to surface a conventional structure but still yield a log cabin look. This article will address the milled full log option. The wood is machined to a uniform size and shape. There are several log profiles available including:

Square/Rectangular The wood is milled with 4 straight edges. One edge may be beveled.

Round The wood is milled round. Round logs may be coped (Swedish cope), i. e., a half moon groove is cut on the bottom to allow them to fit one on top of another.

D shaped The log is milled with flat top and bottom and with at least one round side. The second side may either be round or flat. My preference is the flat and round D shaped log: round on the outside and flat on the inside.

Log Interface

How are logs fitted together to construct the log cabin? Milled flat surfaces fit on top of each other but how is the connection kept solid and air tight? A common connection is the tongue and groove. These can be single or multiple. Tongues are milled on the top of the log and the interlocking groves are on the bottom.

A sealer will be applied to the tongue and groove joints. Another method is to mill a groove on both sides of the log and connect the logs with a wood spline fitting into the grooves. Lag bolts may also be used to secure the logs together.

Corners
There are also a number of different corner connection options for a log cabin.

Dovetail Used with square/rectangular logs, the corner is cut in a fan shaped wedge that interlocks with the perpendicular connecting logs.

Butt One log fits into a cutout of the connecting log

Butt and Pass One log is cutout to snugly fit the outside of the intersecting log.

Saddlenotch Notches in the shape of a saddle are cut on top and bottom of logs. These notches intersect and logs overlap the connecting logs

Corner Post The wall logs are toe-nailed onto a vertical corner post which is commonly bigger than the wall logs. There are no extended log ends.

If there are extended log ends, they can be straight, staggered or curved