We often do not realize how much information is hidden in old beams of historic buildings. Going on a journey in the footsteps of former builders, we can learn interesting things about the structure and its former repairs.
Carpentry joint in Siedlęcin Medieval Tower (Poland)
In historic constructions, joints of wooden elements were made without the use of metal connectors. The elements were connected using carpentry joints, reinforced with wooden pegs (depending on the type of connection). Only at a later time, together with the increase in the span of the structure, began to introduce metal connectors. In uncomplicated constructions as well as during renovations and reconstructions, carpentry joints are used even today.
Crowned construction with a saddle notch corner
Traces of ancient carpenters can become a guide for the history of the building for us, and old beams a source of knowledge about crafts and construction techniques. On the surface ot the wooden elements we can find carpenters' marks that simplified the assembly of the structure (they determined where in the structure the given element should be). They were usually made with chalk or pencil or cut with a sharp tool. The numbering was often Roman numerals or some variation thereof. Based on this marks, it is possible to deduce in which order individual parts of the structure were erected, as well as to determine which elements are original and which were inserted during subsequent repairs and renovations. Traces left on the surfaces of the processed elements of wooden structures can give us information about the tools used - traseology deals with the study of these traces.
Carpenter's mark on the roof structure from XVIII century
Carpenter's marks on the half-timbered structure form XIX century
It is worth to remember about carpenters' marks and take care of them during renovation! If their removal is necessary, due to biological corrosion, it is best to document them in advance.