Round timber in construction: An introduction
Prepared by TRADA Technology in 2003 for the Forestry Commission and published here with their permission.
Wood is man’s oldest structural material, and prior to the introduction of tools such as saws it was largely used in its natural round form, often connected together with lashings rather than by mechanical jointing. The earliest simple pole structures were probably nomadic homes such as wigwams and yurts with saplings forming the structure and covered with leaves, skins or felt.
This early form of construction led to the design of all the classical styles of architecture both Western and Oriental which evolved from the use of round wood for supports. Tree trunks were still used as columns long after the classical period and the pole supports of such buildings as the Stave churches (standing poles used as columns) of Norway which still survive since their construction in the 12th and 13th centuries.
Figure 1. Norwegian Stave church
In many countries simple round wood structures have been used traditionally for agricultural buildings, but quite major engineering structures such as bridges have also used wood in this form. This includes the early historic bridges of China and Japan through to the large span trestle bridges built for the American railroads in the 19th century.
Pole construction has always been used for marine construction – piers, jetties, docks etc, where it has often survived for many centuries despite being partially submerged and exposed to extreme weather conditions and structural forces.