Wood and Wood Joints: Building Traditions of Europe and Japan Edited by Klaus Zwerger. Birkhauser, 1997. 280pp. £44 approx. (Distributor 0181 542 2465)
This book compares and explains the European and Japanese traditions of making joints exclusively from wood, without adhesives or metal connectors. But why include Japan when the wood-joint tradition within Europe itself is so diverse? Zwerger explains that both areas had a timber building boom in the Middle Ages and both developed joints of quite remarkable complexity, and some similarity.
In any case, after a few pages, Zwerger's enthusiasm and Teutonic thoroughness disarm criticism. Here is a man whohas trekked through the wild Carpathian forests, the Norwegian outback, the Russian steppes and obscure regions of Japan in pursuit of the wood joint. He tells the story with a sense of unfolding discovery; for anyone interested in how buildings work this book is a joy to read.
Zwerger explains and illustrates the properties of wood and the vast vernacular knowledge acquired by those who used it: how trees can grow with a twist in the trunk from tracking the sun like sunflowers (the Japanese allowed for this), and how, before 1350, the Norwegians developed the findalslaft, a complex corner joint for log buildings, which allowed water to drain off.
The way joints are made, and how whole structures are assembled are also explained, together with the structural principles involved, and the philosophy behind the design. In particular, Zwerger shows how the form of the joint reveals the thought processes of the maker. The man who had the knowledge to make the joint was in control of the building operation. Daiku, the Japanese word for carpenter, corresponds to the Greek roots 'archi' and 'tecton', exposing the master carpenter as the forerunner of the architect in both Japanese and European cultures.
Zwerger describes the tools of the trade, and the great reluctance of craftsmen everywhere to use the saw, which tears the cellular structure of wood. The adze, plane and spokeshave were preferred. The Japanese shunned the drill for the same reason and perfected a range of hand-forged planes and chisels.
'The earlier a civilisation experienced a Golden Age of timber in its history, the sooner it lost its forests,' Zwerger observes. This was true of Europe and also of Japan, where a new style of timber architecture was established using shorter and smaller-sized members. As a result the joints became increasingly complex, culminating in almost unbelievable wizardry. The raised eaves corner of the thirteenth-century Engaku-ji in Kamakura, Kanagawa is supported by five three-dimensional stacks of cantilevered brackets. Europe responded in a similar manner; the English hammer-beam roof uses relatively small components.
The men who made the woodjoints are no longer in control. This book is a humbling reminder of their intuitive grasp of structural engineering and design.