In the past 11 or 12 years, the technique has become more popular outside of Japan, he explained. “It is often said that this authentic traditional Japanese heat treatment process is a gift from mother nature rather than a scientific construction method technique,” Kimura noted. For centuries, yakisugi was only popular in Western Japan, where Kimura said it was used for “exterior siding and fencing on traditional Japanese houses due to its remarkable durability.” Kimura explained that in addition to possessing the above qualities, the yakisugi technique also makes wood fire-retardant. “By slightly charring the surface of the wood, you essentially get rid of its softer outer layer,” he noted. “When the wood is being burned, the porous material within the wood’s inner layer starts to close its pores and becomes much more stable and durable. This carbonization process of the outer layer of the wood creates a layer of carbon that prevents the wood from burning quickly.” If this wasn’t beneficial enough, Kimura noted that burning the wood also prevents it from rotting and pests. “Termites and other wood-consuming insects hate the layer of carbon produced by charring,” he stated.
