7 Things You Need to Know About Japanese Joinery

by Cole Lubchenko | CRAFT

Japanese woodworking is a traditional practice with a long history carved out by master craftspeople. Like any traditional Japanese art, from sushi-making to flower arranging, it is full of practitioners who have dedicated their lives, generation after generation, to reaching an seemingly unattainable level of perfection. We’ll take a look at what makes Japanese woodworking unique, including what makes perfect joinery, the razor sharp set of hand tools, the intricate techniques, the applications of the practice, and where you can see and purchase products made by these traditional methods.

1. What makes Japanese Joinery Unique?

Joinery refers to both the wooden components of a building, and the techniques used for making those components. The craftsperson who does this is often considered a joiner, as he or she is one who joins pieces of wood together to construct something. Traditional Japanese joinery is made entirely without the use of metal fasteners or adhesives.

While building without the use of nails or other fasteners is not at all unique to Japan, the types of joints used, the durability of the structures created, and the complete absence of iron makes Japanese joinery stand out.

European and American architecture make use of similar joinery techniques, but often as a means to an end. After all, woodworking is, before anything else, a practical craft used to make practical goods and buildings. In Japan howeverm complex methods of joinery are used not only for practical reasons, but also to highlight craftsmanship, and to enhance aesthetic quality. These decorative joints have often been used in temples, shrines, and castles, but are particularly common in furniture making.

Another key difference is that American and European architecture often used nails in circumstances where it would be beneficial to use them, but Japan had very low-quality iron that resulted in brittle nails that rusted easily. This forced Japanese builders to come up with ways of constructing buildings that didn’t use metal components at all.

2. What Kind of Wood is Used for Japanese Joinery?

Not just any wood is used when making furniture or building structures with joinery techniques. The species of wood is carefully selected based on its qualities. Attributes like hardness, resistance to rot, moisture content, scent, color, and size are all considered.

When making cabinets and boxes lightweight Paulownia wood (kiri) is used. Paulownia is a fast growing hardwood; in fact, it grows so fast that in some parts of Japan, when a daughter is born, a Paulownia tree is planted for her. Then, when she gets married, the tree is cut down and used to make her a bridal chest of drawers. The wood naturally protects against humidity which allows delicate items to be stored safely.

Japanese cypress (hinoki) is often used in the construction of structures that are intended to last for centuries. Castles, temples, shrines, and palaces all make use of this highly rot-resistant wood. The world’s oldest wooden building, Horyu-ji in Nara, was constructed using this wood and has continued to stand for over 1300 years.

3. What are the Most Important Japanese Joinery Techniques?

Most joinery techniques make use of mortises and tenons, and Japanese traditional joinery is the same. A mortise is a hole or recess carved into wood, and the tenon is the corresponding piece which fits into the mortise. However, this simple description doesn’t do much to explain the elaborate construction of these joints.

In traditional Japanese joinery, there are around 30 basic types of joints. Joinery can be used to combine pieces to make a beam longer, to attach pieces at perpendicular angles, or in fact to join pieces in just about any conceivable way. Sometimes the joints are made decoratively to show off the technique of the artist, and sometimes they are completely concealed to show off the beauty of the wood grain.

Joints are either constructed to only use friction as their main method of holding the pieces together, or with a wooden peg that is hammered in tightly to push the pieces together snuggly. Friction fit joints, like the dovetail joint, are often used to attach pieces at right angles in the construction of boxes or drawers. Joints with wooden pegs are often used in scarf joints to attach two pieces end to end to make a longer piece of wood. However, both types can be used in a huge variety of ways.

4. What are Traditional Japanese Woodworking Tools?

Of course, to make such precise joints, you need to have equally precise tools. Craftspeople who use traditional Japanese techniques make use of a large array of tools, and for each tool, there can be dozens of sizes and varieties, all razor sharp. While for larger projects power tools are occasionally used, it is fine hand-tools that are used to make the intricate joints necessary to make their projects.

Japanese handsaws (nokogiri) are used to make straight cuts in wood. The saws are relatively thin when compared to non-Japanese saws. This is because the saws use a pull-stroke rather than the much more common push-stroke.

Japanese planes (kanna) are used to make a piece of wood flat by removing thin flat sheets of the wood by pulling or pushing a blade across it. Japanese planes are similar to western style planes, except that the blade is convex, rather than flat. Japanese planes, like the handsaws, are used in a pulling motion, rather than pushing. This tool is essential to the Japanese craftsperson, some of whom will have over 100 varieties of handplane.

The plane is such an important tool that there is even a competition to judge who can plane the thinnest sheet of wood off of a much larger timber. The champions of this competition can plane sheets as thin as 5 microns thick. For reference, a human hair is roughly 70 microns thick.

Japanese chisels (nomi) are narrow blades used to remove material and make notches or holes in wood. Chisels come in a huge variety of shapes and sizes. They are incredibly sharp, and made of hardened steel so they can cut through wood easily.

Of course, there are many more tools on a typical Japanese craft person's workbench, but these three tools are the most important, and most frequently used instruments in Japanese joinery.

5. How is Japanese Joinery Used in Architecture?

When it comes to architecture, Japanese joinery has a number of practical reasons for why it was so commonly used in the construction of traditional buildings. While it's true that Japanese builders didn’t have easy access to high-quality iron, there were other reasons for them to avoid the use of nails. Firstly, nails make wood more susceptible to rot. Moisture seeps in around the nail and down into the wood; this makes the wood less durable in Japan’s wet and humid weather. Additionally, joinery allows pieces to be replaced as they wear and weather. Adding nails makes it harder to replace pieces due to the remaining nail holes after pieces are replaced.

Not only does this nailless construction result in the ability to easily repair buildings, it also makes buildings more resilient against Japan’s frequent earthquakes. The joints have more freedom to sway with the forces of the earthquake while still maintaining their integrity. While this isn’t the only technique that has kept these buildings standing after hundreds of years, it is certainly a significant factor. Similar techniques continue to be applied even in modern construction. Tokyo Skytree famously borrows concepts from traditional earthquake resistance in its design.

6. How is Japanese Joinery Used in Furniture Making?

© Toyoda Woodworks, Kumiko Screen — © Toyoda Woodworks, Kumiko Screen

Joinery techniques in furniture making (sashimono) can be even more complex and precise due to the softer woods used. Some drawers and boxes can be so precisely built that lids and doors close gently due to them being nearly air tight. Instead of closing the lid and having it slam down on top of the box, it will slowly slide down as the air leaks out; it creates an incredibly refined-feeling product.

Another example of amazing complexity in furniture making is kumiko woodworking. This style uses hundreds of pieces of carefully arranged wood assembled in intricate and symmetrical patterns. These pieces are often used for sliding doors or cabinets, and you can see many examples in 6 Things You Need to Know About Kumiko Woodworking!

Joints that use two types of wood can create a product with beautifully contrasting colors that highlight both the quality of the wood used, and the craftsmanship that went into making the product. While some joinery products conceal the joints, these ones turn them into a feature that enhances the item’s appearance.

Since joinery doesn’t cause holes in the material, and it is relatively easy to disassemble. In the spirit of mottainai, pieces of furniture that are no longer useful to their owners can be taken apart and rebuilt into something that is more suitable. Taking apart a chest of drawers to make several small boxes, or a more modern item like a TV stand is entirely possible without destroying the well-aged materials.

7. Where Can I Buy Japanese Joinery?

Antique Yamamoto on Inokashira Street about ten minutes from Yoyogi Uehara Station (see map) has a large collection of used traditional Japanese goods from many eras. You can visit their website to get an idea of what they have, or visit the shop to see the masterfully crafted furniture in person.

If you are interested in modern Japanese furniture, the aptly named furniture street near Meguro Station is a must visit spot. The street has lots of imported vintage furniture, but if you look for it, you will find some amazing high-end Japanese furniture as well.

Outside of Tokyo, there are plenty of options for towns that specialise in joinery. Check out these 6 Best Places to Experience Japanese Woodworking!

If you are interested in the architectural side of joinery, visit any temple or shrine and pay close attention to the details. Once you start looking for the precision and skill with which these structures were built, you will be even more impressed. Knowing what goes into the design and construction of traditional Japanese buildings makes them much easier to appreciate, and you can be sure you will find yourself getting lost in the details of any shrine or temple you visit in Japan.