JAPANESE
SAWMILLING About Japanese Sawmilling

Understand the differences and deepen your knowledge

Features of Japanese Lumber

 
Japan has long built houses primarily from wood.
From this tradition, unique Japanese sawing techniques and a distinct lumber culture have developed, so Japanese lumber products differ in many ways from those produced overseas.

① Most Japanese sawn timber is
used for wooden housing

Japan has a long history of building wooden houses, forming its own unique market. Each building component has its own name, and standards vary slightly depending on the region.

② “KIDORI” – Cutting logs according to wood characteristics

“The core contains many knots but is strong, while the outer part has fewer knots and is suitable for interior materials.” Japanese carpenters have long utilized these characteristics to create multiple components from a single log. This method is called “Kidori.”

Many sawmills automate this process, as seen in the video on the top page. Each sawmill has its own specialties and available sizes. Large factories also have limits depending on the specifications.

③ Sorting logs for construction use

In Japan, where timber has long been used for homes, the most important factor in log quality is straightness. At log markets, logs are categorized based on how much they curve. Sawmills for construction timber rarely use logs that are significantly bent. Most products are made from straight or slightly curved logs, resulting in high-quality, stable lumber.

④ Knot-free lumber is extremely valuable

Hinoki and sugi are coniferous species and naturally have many knots. Obtaining knot-free lumber suitable for interiors is difficult. Japanese foresters developed the “branch pruning” technique, removing branches as the tree grows to produce high-quality, knot-free logs. Such logs sell for two to three times the price of ordinary logs.

These special logs are used for temples, shrines, and premium interiors in Japan, making them rare and expensive.

Hinoki 5m–6m knot-free boards

Branch pruning work

Years grown after pruning

These products are sawn at specialized mills.
Some mills also collect knot-free boards that happen to appear during mass production.
These are cheaper than specially cultivated lumber but still cost more than standard knotty lumber.