Traditional Japanese joints and their head book

The other day someone suggested to me, with regard to traditional Japanese carpentry, to take up the subject again and develop it, as it is a very interesting one. As I had been wanting to do this for a long time I found the recommendation welcome, so I set to work. I find traditional Japanese carpentry fascinating and I think I could read for hours, without tiring, to learn as much as possible. In fact, that's pretty much what's been happening lately. So I'm going to tell you a little more about traditional Japanese joinery, and the passion with which it is preserved despite all the modern techniques now used in construction and furniture making.

With modern means of documentation, it is not difficult to find examples of such combinations. Find descriptions, photos, videos and gifs showing you what it takes to get the perfect match.

What's harder is finding the stories among this information. And luckily I found one of them which, even if not extraordinary, certainly demonstrates the Japanese desire not to lose their cultural heritage and traditions.

In 1989, a technical book appeared in Japan which describes in detail, with sketches, top, front and side views, dimensions and photographs, the traditional joints made without using any other auxiliary material. Basically the joint is made by giving each part a specific shape. Put together, the parts fit perfectly without screws, nails, glue or other such materials.

Two types of joints are described - demountable and non-removable. At first glance you would think that there are not many variants for each of these types, but this is not really the case. In the book there are 9 demountable and 13 non-removable joints, with up to 5 variations for many of them. They have exotic names like Kanawa Tsugi, Mechiire or Dodai Shiguchi and some of them are really complex.

It's amazing how they could imagine how the joint would look. Now, when you can make computer programs for any kind of cutting and joining, and you can do it with CNCs, it still seems hard to think of a construction of just joints without any helpers. In the past, everything was done by hand, with classic tools, and the result was perfect and took centuries. In addition, everything was designed in such a way that the grain of the wood did not have to suffer in order not to affect the durability of the joint.

What got me talking about the book was, perhaps more than what it contains, the story of its appearance. The book has 2 authors, Torashichi Sumiyoshi and Gengo Matsui. The former is a master carpenter born in 1911, who learned about traditional Japanese carpentry in castes that pass down the art of woodworking from generation to generation. Since 1924 he has been working with wood with his own firm and has become a member of organizations that build and restore temples.

The second is a renowned university professor at Waseda University. Matsui graduated as an architect from the university in 1943 and returned there as a professor after receiving his doctorate in 1960. The two met in 1985 when they worked together on the design and construction of Eishin Gakuen Higashino High School, together with English architect Christofer Alexander. Eishin Gakuen is renowned for its wooden structure, especially as it came into being after a long period when such buildings had not been built.

Matsui was impressed by Sumiyoshi's artistry in making joints, his simple way of working. It was a way of working that he had learned nothing about in school. But those simple joints were so solid and so correctly and accurately made as if they were the work of a scientist. He decided then that this knowledge should not be lost, that it was a real treasure and that builders, engineers and architects should be able to study it in school. This is how the book came about, in which the drawings were made by Waseda University students according to the carpenter's precise instructions.

As I said, the book was published in 1989, and by 1990 the second edition had already appeared. The English-language version was not long in coming, and was already available in 1991. Since then the book has been a staple for many craftsmen around the world, with new editions being printed. You can find here first edition version which I'm sure enthusiasts will see as a real treasure.