Yakisugi is a building material made by charring the surface of cedar boards. In Japan, it has traditionally been used as an exterior cladding material.

While the base material is the same as untreated cedar, the key difference lies in its durability against ultraviolet (UV) exposure. Compared with untreated cedar boards, Yakisugi has a carbonized surface layer that protects the wood from UV rays. This significantly slows down discoloration and deterioration caused by sunlight, allowing the deep black appearance to be maintained for a much longer period.

In addition, the carbonized layer helps prevent decay, and Yakisugi is more resistant to fire, as its ignition temperature is higher than that of dried, untreated wood.

We are sometimes asked, “Does Yakisugi have insect-repellent properties?” From the perspective of Kyoei Lumber, we believe there is no significant difference compared to untreated cedar in this respect.

At Kyoei Lumber, we not only produce traditional Yakisugi with a fully carbonized surface, but also develop a wide variety of finishes, including boards with the charcoal layer brushed off and boards with additional coatings or paint applied.