Carbonized Wood: A Traditional Japanese Technique That Has Conquered the World

Ancestral, vernacular, and minimalist. For many, these three words have come to define the architecture of Japan, a country that has served as a source of cultural and technological inspiration to countless cultures.

In recent decades, popular Japanese techniques have spread throughout the world, not only in the field of technology but also in technical and artistic areas. In architecture, the appropriation and reinvention of different materials and construction techniques, such as the carbonization of wooden facades, has been a continuing theme.

The popular technique, now more than three hundred years old, that is known in Japan as Shou Sugi Ban, was developed on the island of Naoshima to treat wood used in the construction of traditional fishing villages. The treatment was designed to combat the damage to the wood caused by the effects of the sea. Originally, the process entailed burning the outer layer of the wood with the use of fire, however, the method usually now sees the boards charred by a torch. By doing so, the external fibers of the wood are forced to react, leaving the wood behind immune to the attack of termites, fungi, and other natural forces for decades.

The carbonization process must be carried out by companies or specialists trained in the technique. The procedure consists of four steps. First, the burning of the wood, which can be done either before installation or applied directly to the installed facade. After firing, the wood is brushed with a special grit, removing the top layer of carbon, and giving the wood its new shade. In the last two stages, the wood—already black in tone—receives a special layer of waterproofing with cedar oil to ensure greater resistance, before finally receiving a layer of sealant, to avoid stains being caused by the charred facade.

The Japanese architect Terunobu Fujimori appropriated the process of carbonization of wood, previously used only in vernacular projects, and innovated. His work gave notoriety to the technique, so that boards that had been sealed and treated against the effects of time also happened to give singular compositions to his façades.

In Japan, the traditional technique had been replaced by the use and application of other materials such as polymers, stone, and aluminum. However, Fujimori was the one who popularized the technique by showing off its apparent simplicity, spreading it beyond the borders of Japan. The technique's austere and peculiar appearance has caused architects in different parts of the world to appropriate it, reinventing it with new applications and compositions

RT Residence / Jacobsen Arquitetura