What is Japanese burn board technique, or Shou Sugi Ban? Originating in 18th century Japan, shou sugi ban is a particularly striking method of preserving wood by charring it with fire. It may seem that charring wood is a way to break it down, but charring is actually an ancient technique that is tried and true in weatherproofing buildings.
Traditionally, this practice is used with Japanese cedar in order to weatherproof it. The wood is burned until the surface is charred, and then coated with natural oil. Charred wood can serve as a fire retardant, since it lacks the oils needed to ignite a flame; this helps shou sugi ban surfaces last for many generations. You can even find variations elevated to fine art, as in the work of the artist Maarten Baas. The gravitas imparted by the process and finished result (called yakisugi) are undeniable, a blackening of the wood that reveals clean, distinct lines and an inherent textural beauty. You might not be the proud owner of a blowtorch (yet), but any intrepid DIYer can absolutely accomplish the technique at home to give an existing piece of wood furniture a new look. We will walk you through the history of this incredible invention, then delve into all the details of how you can do your very own. My first introduction to the technique was watching the Netflix series Home, where a couple in Maine built a beautiful home using Japanese Burn Board. It has spread all over the world, and become somewhat of a trend in recent years.
History of Shou Sugi Ban
Shou sugi ban evolved in eighteenth-century Japan as a way to build housing using a readily available building material—Japanese red cedar (Cryptomeria Japonica). Japanese builders had to consider the local climate, which can be humid with extreme temperature fluctuations between seasons. Additionally, homes lining Japan’s coastline contend with salty ocean spray, which can wear down a building’s cladding and decking. The shou sugi ban technique provided a cost-effective way of weatherproofing Japanese homes. Burnt cedar siding naturally resists destructive environmental elements, and its appealing matte finish and relatively simple manufacturing process have contributed to its lasting popularity.
English-speakers know this charred wood as shou sugi ban, but in Japan it’s called yakisugi, yakisugi-ita, or yakiita. Researchers from the University of Tokyo found that the earliest written record of the word “yakisugi” is from a dictionary published in only 1930. Centuries-old structures clad in charred wood and oral tradition dating back to the Edo period (1603–1867) is compelling evidence that “yakisugi” is a fairly new term. If shou sugi ban was known by other names in the past, those older names may be lost to antiquity. Prior to 1970, shou sugi ban had a reputation as a poor man’s building material installed on storehouses in industrial zones and on residences in areas not easily visible to passersby. Today, shou sugi ban is being used in high-end, modern spaces.
Between 1603 and 1868, during the Edo period, there was unification occurring in Japan, as they experienced a huge population boom and a new, rigid social stratification system was put in place. By the 1750s, Edo was likely the most populous city in the world. The bottom rung of the social ladder was the merchant class, a populous group in the dense urban center of Edo. They built and occupied machiya, traditional wooden townhouses, and stored their goods in warehouses known as kura. Aside from being the new center of political power and the cultural mecca of Japan, the dense urban center of Edo was ripe with these traditional wooden townhouses. Susceptible to tragedy of flame, nearly 1,800 fires were recorded during this period—destroying countless structures and killing thousands of people.
It’s important to clarify that Yakisugi is a thin plank used for wall, fence or ceiling, not a surface treatment. It is never made from reclaimed wood, driftwood, or chemically treated wood. The best results use only Japanese Cypress, and the technique cannot be replicated without the traditional drying and contained heat treatment process. It is not burned with a torch, kiln dried or burned after instillation. The word Yakisugi describes a finished product, not a verb or adjective. In the beginning, craftsmen burnt wood by erecting a tipi-like structure made of partially dried planks. At its bottom, they’d start a fire. As the fire burned, temperatures within the timber tipi would rise to over 400˚C, charring the boards in minutes.The combustion also neutralizes the cellulose in the wood — the carbohydrates that termites, fungus and bacteria love — making it undesirable to pests and resistant to rot. The resulting charcoal layer repels water and prevents sun damage as well. By some estimates, boards that have undergone this process can last 80 years or more, but Japan’s Buddhist Horyuji Temple in Nara prefecture, whose five-story pagoda is one of the world’s oldest extant wooden structures, has been around for much longer. Initially built in A.D. 607, the pagoda caught fire and was rebuilt in 711 using shou sugi ban.
Now, it is not hard to imagine that using a fire-resistant material was a priority, especially among those that couldn’t afford to build with stone or stucco. Enter Shou Sugi Ban. By the end of the Edo period, many of the merchant class had amassed considerable wealth and status despite the rigid class system imposed on them. The shou sugi ban on their warehouses protected their goods, and on their homes protected their families. The application of Shou Sugi Ban is limitless, with the method turning both interior and exterior home elements into durable, state-of-the-art structures. A faithful companion of imagination, it allows everyone to decorate and protect their dwelling as they wish. With its mesmerizing history and technique, the method’s emotional undertone breathes through the strong structures of your home, giving it a unique charm.
The charred wood that protected those structures waned in popularity as the populace began to favor new materials and pre-existing technologies became more affordable. Shou sugi ban regained popularity in Japan in the 1970s, giving rise to mills specializing in large-scale manufacture of shou sugi ban. Architects like Yoshifumi Nakamura are internationally known for projects featuring charred wood, and have bolstered its popularity by holding special exhibitions and workshops around the world demonstrating traditional manufacturing techniques and experimenting with different wood species.
Contemporary Burn-Board Technique
As a current trend in modern architecture you can expect Shou Sugi Ban to be seen in both exterior and interior settings, even being used on furniture and decor. However, where Shou Sugi Ban really shines is as exterior siding or interior wall accents. Despite being a very old method of treating wood, it is flexible enough to look stunning in both modern and rustic settings. ‘‘It’s become quite stylish,’’ says Marc Keane, a landscape architect and author who has lived and worked in Kyoto for 18 years, ‘‘but in the past, in Japan, it was considered countrified.’’ Why has it risen in popularity recently? Well, collectively as a society, we have pined for earlier days and the handcrafted elements that will take us back there. Perhaps as a rebellion against the ever rapid expansion of capitalism and commodification, many are choosing slower forms of production with ancient techniques. So, many have adopted principles that have long been fundamental to Japanese architecture: simplicity, the use of natural materials and a sensitivity to the surrounding environment.
In addition, the technique has been incorporated into sleek minimal lines and design, resulting in charcoal grey or black flat facades that stand out starkly, but beautifully in the midst of nature. The unpolished, naturalistic quality of burnt wood also appeals to architects seeking to evoke a rough organic feel in tune with the surrounding landscape. ‘‘The American architects who are using it often don’t go the full route. It’s a bit too extreme,’’ says James Steele, a professor at the University of Southern California and the author of ‘‘Contemporary Japanese Architecture.’’ There are many modern takes on the technique, which produce a similar result, but many traditionalists disagree that it is the same thing at all. Not all woods take heat the way Cryptomeria japonica does, and if the burn isn’t deep enough, the sooty layer will erode, taking the lovely black of your cladding, and its pragmatic fire- pest- and weather-resistant properties, along with it. Yet even when shou sugi ban is executed traditionally, the sooty black char does eventually fade, leaving a chocolaty-brown or warm gray hue behind. This can be seen in Japan’s many historic examples of the treatment, like public municipal buildings in the downtown of Kurashiki in southern Japan, which are close to 100 years old. This is part of the life of the wood, and an important part of the technique. Many people today want the aesthetic, and they want it to last forever. There are, indeed, ways to do this: but, I would caution against calling them Yakisugi.
In the episode of Home, featuring Anthony Esteves and Julie O’Rourke, he explains his process of discovering the technique. Esteves says ‘‘A lot of people don’t think shou sugi ban is for them, because it has this impermanence to it,”. He learned about the method while studying in Japan and used it on the raven-colored rustic home he hand-built off the coast of Maine, burning all the siding himself in the time-honored three-board method. But the alternative view is that the patina that comes with age is desirable: the impermanence and its attendant imperfections are the point. ‘‘Over time, my house will weather in this soft way,’’ Esteves says. ‘‘It’s going to become more beautiful.” So, if you’re someone who appreciates handcrafted elements, natural materials, and allowing things to change and mature over time, this may be something to try!
How to Do it Yourself
Although you may consider fire to be an enemy of wood, only causing its degradation, Shou Sugi Ban actually enhances durability and is a natural means of preserving wood without chemicals, paints and other surface treatments. It is a technique that requires some skill, and attention to detail. The first step is selecting the right wood. This is an essential step, and one not to be passed over. Cedar works best for shou sugi ban because of its natural chemical properties. Cedar is a lighter, more porous wood, and there’s a chemical component to it which makes it work better for this technique. In the traditional procedure, three boards of Sugi will be bound together to form a triangle. After binding the boards tight, fire is lit on the very bottom with some paper or newspapers. It then takes a minute or two for the fire to proliferate, usually it starts to spread fairly quick due to the chimney or stack-effect from the triangle of boards. The time required until finish depends on the initial moisture grade of the timber as well as the desired degree of burning. In order to let the outer 3-4 mm charred, it usually will not exceed ca. 5 minutes. In this traditional way to burn, the heat inside the triangle needs at least 250°, but mostly reaches >400°C. After reaching the desired grade, the triangle is opened and the fire extinguished by applying water.
It is also important to dry down the timber boards before burning, ideally to somewhat 10-15%. This ensures good results in the burning process, reduced warping and increased longevity. In past times, the whole process was done by carpenters mostly on a nearby dam aside a river or on harvested rice fields. Now, it is possible to achieve similar results without using the exact technique. Many people do use a blowtorch and just scorch the boards on one side. In order to obtain a consistent-looking final finish you need to be very precise. The torch needs to be passed at the same speed and held the same distance from the wood to get a uniform burn. This can also be done using coals from a fire, but this will likely result in a far more inconsistent final finish. Next step is brushing off excess carbon. Keep an even pressure on the brush, and always go with the grain. This stage may actually help you bring boards back to a desired colour if you over-burned them a bit in places, by brushing a little more vigorously. When oiling the wood, spread it evenly over the surface with a rag or brush (going with the grain of course). Wipe off the excess and allow it to dry; a second coat of oil at this point is recommended.
You’d need to be okay with slight variations in colour and consistency if you want to try this yourself, but if you really want it uniform in colour, it is best purchased from a professional manufacturer. There are certainly different scales of sticking to tradition with this practice. I think it’s important to recognize and honour the history and cultural significance of Shou sugi ban, while adapting it to your needs. It is accessible and not too difficult a DIY project, whether done in the classic pyre format or just with a blowtorch. Either way, you are literally playing with fire, so make sure safety is your number one priority, and you consult some experts before starting.