A timber cutter's mountain log cabin at the Museum of Folk Architecture, Pyrohiv
Construction with logs was described by Roman architect Vitruvius Pollio in his architectural treatise De Architectura. He noted that in Pontus (modern-day northeastern Turkey), dwellings were constructed by laying logs horizontally overtop of each other and filling in the gaps with "chips and mud".
Historically log cabin construction has its roots in Scandinavia and Eastern Europe. Although their origin is uncertain, the first log structures were probably being built in Northern Europe by the Bronze Age (about 3500 BC). C. A. Weslager describes Europeans as having:
... accomplished in building several forms of log housing, having different methods of corner timbering, and they utilized both round and hewn logs. Their log building had undergone an evolutionary process from the crude "pirtti"... a small gabled-roof cabin of round logs with an opening in the roof to vent smoke, to more sophisticated squared logs with interlocking double-notch joints, the timber extending beyond the corners. Log saunas or bathhouses of this type are still found in rural Finland.
By stacking tree trunks one on top of another and overlapping the logs at the corners, people made the "log cabin". They developed interlocking corners by notching the logs at the ends, resulting in strong structures that were easier to make weather-tight by inserting moss or other soft material into the joints. As the original coniferous forest extended over the coldest parts of the world, there was a prime need to keep these cabins warm. The insulating properties of the solid wood were a great advantage over a timber frame construction covered with animal skins, felt, boards or shingles. Over the decades, increasingly complex joints were developed to ensure more weather tight joints between the logs, but the profiles were still largely based on the round log.
Nevertheless, a medieval log cabin was considered movable property (a chattel house), as evidenced by the relocation of Espåby village in 1557: the buildings were simply disassembled, transported to a new location and reassembled. It was also common to replace individual logs damaged by dry rot as necessary.
The Wood Museum in Trondheim, Norway, displays fourteen different traditional profiles, but a basic form of log construction was used all over North Europe and Asia and later imported to America.
Log construction was especially suited to Scandinavia, where straight, tall tree trunks (pine and spruce) are readily available. With suitable tools, a log cabin can be erected from scratch in days by a family. As no chemical reaction is involved, such as hardening of mortar, a log cabin can be erected in any weather or season. Many older towns in Northern Scandinavia have been built exclusively out of log houses, which have been decorated by board paneling and wood cuttings. Today, construction of modern log cabins as leisure homes is a fully developed industry in Finland and Sweden. Modern log cabins often feature fiberglass insulation and are sold as prefabricated kits machined in a factory, rather than hand-built in the field like ancient log cabins.
Log cabins are mostly constructed without the use of nails and thus derive their stability from simple stacking, with only a few dowel joints for reinforcement. This is because a log cabin tends to compress slightly as it settles, over a few months or years. Nails would soon be out of alignment and torn out.
Ornamental woodcarving in the shape of an eagle's head on a projecting log in the wall of the loft from Ose at Norsk Folkemuseum.