There are two representative methods for producing Yakisugi: the Triangle Charring Method and the Machine Charring Method.

The Triangle Charring Method is a traditional technique in which three cedar boards are assembled into a chimney-like structure, and a fire is lit inside to char the surfaces.
This method is often associated with a thicker charred layer. However, there is not necessarily a significant difference in performance, such as durability. In fact, there are many examples in Japan of buildings clad with machine-charred Yakisugi that are over 40 years old and still retain a sound charred surface. For this reason, the belief that machine-charred Yakisugi is less durable is a misconception.

The Machine Charring Method, by contrast, uses a high-temperature furnace to char the boards in a short period of time. This approach offers higher productivity and allows for more consistent quality, while also helping to reduce costs.
A process that can take approximately two weeks with two people using the Triangle Charring Method can be completed in about two hours with the Machine Charring Method.

In addition, compared with the Triangle Charring Method—which involves handling boards at very high temperatures by hand—the Machine Charring Method offers advantages in terms of safety during production.

While the Triangle Charring Method holds cultural value as a traditional technique rooted in Japan’s wood culture, Kyoei Lumber believes that, in order to preserve this culture and carry it forward into the future, it is equally important to create an environment in which Yakisugi can be used by more people through production methods that emphasize economic viability and sustainability.