Wood Techniques II.

Log and beam constructions

On the area of the present-day Czech Republic, the fundamental construction design of wooden homes and farm buildings is the more difficult construction of log structures, later replaced by beams. This wooden structure was used in parallel with the previously mentioned techniques.

Two-storey house built of logs.
Two-storey house built of logs (small town of Úpice, Trutnov District, Hradec Králové Region, northeast Bohemia)

Logs

The older method of timbering consisted in using tree trunks or logs in their original profile, characterised by only the necessary rough-hewing and with the ends extending beyond the entire height of the wall. The logs were notched at their point of intersection and fit alternatively into each other. This antiquated method of carpentry joints was mainly documented in archaeological field research of extinct Slavic fortified settlements and was probably still in use in the 15th or even the 16th century.

Corner joints

Cabins made of non-hewn or hewn logs that did not extend beyond the corners appear later but still reach back significantly. The change consisted of difficultly executed carpenter ends into dovetail joints. This change occurred unevenly over time and within the present-day Czech Republic. In some regions the change did not occur along with the entire height, the overhangs being retained in the upper or lower logs or both. This was more common in the Pošumaví region in south-west Bohemia even in the case of later houses. Overhangs were retained the longest in the upper part of the walls because they bore the roof structure.

Horizontal joints

An integral part of walls built of logs or beams was the filling of the horizontal joints. Long poles corresponding to the profile were used for larger joints, while three-sided laths were used later. The joints were caulked with moss and screed in both cases.

Beams

The latest wooden buildings were built of fully quadrilateral hewn beams. Carpentry work advanced gradually from logs of circular profile to rectangular beams. In some outlying regions with deciduous wood, certain types of buildings were not impacted by this even in the later period. Again, these were especially barns without high aesthetic or thermal insulation demands.

In houses, development moved towards the use of beams, although only partially hewn at first. The bottom and top parts, i.e. the horizontal joints, were at first hewn for structural reasons. Creating the smooth surface of a wooden wall was the most difficult work for a carpenter, so its first use was for the interior of the living room.

Corner and horizontal joints

In addition to the previously used dovetail joints, beams were also joined in difficult ways, albeit less frequently. This especially applied to the most stressed part of the construction. Moss and screed were sufficient for caulking the smaller horizontal joints. In some regions, the hewing was so precise that the joints fitted tightly and caulking was not needed.

Author © Martin Cernansky