Shou Sugi Ban: The History of a Fascinating, Natural Cladding Solution

japanese timber treatment

The culture of Japan has long fascinated the west, with cutting-edge design trends being influenced by Japanese aesthetics for centuries. You only need to take a quick walk down the high street to see self-consciously Japanese items like ash-glazed bowls and glossy black lacquered surfaces in the windows of countless trendy shops – to say nothing of all the tattoos in Japanese script.

Long before we were scrabbling around in dark fields looking for Pokémon, even before we decided sometime in the 80s that ninjas (in a hard shell or otherwise) roamed the streets of Manhattan, artists and architects have turned to Japanese design for inspiration. From the enterprising potters of Delft none-too-subtly ripping off Japanese Imari pottery, to the elegant “japonisme” of Charles Rennie Mackintosh, Japan casts a long shadow in the imaginations of western designers. It’s easy to see why, as Japanese artists have always strived for elegance and simplicity, whilst highlighting the natural qualities of the materials they work with and embracing the random, the accidental and the perfectly imperfect, all of which are hugely important to modern designers. One trend more than any other seems to exemplify all of these ideas: the craze for all things ‘Shou Sugi Ban’.

Like the crooked and enigmatic cottage of some fairytale witch, Terunobu Fujimora’s Yakisugi House crouches in its landscaped garden like a couchant cat, it’s bartizan-like tower, jutting impossibly out at a right angle to the walls, seems to balance precariously on a column of air.

From a distance, the siding of the house appears to have been painted in alternating stripes of black and white, but as you approach, the incredible texture becomes apparent, at once like the gnarled bark of tree and the shining, lustrous black of a cured reptilian hide – a patent leather shoe by way of a stegosaurus. These black boards – dramatically paired with white stucco – aren’t painted, but instead have been carefully and selectively charred to create a product known as yakisugi.

shou sugi ban building in japan
Photograph by Edmund Sumner

Literally meaning “charred cypress”, yakisugi has come to be known in the west as ‘Shou Sugi Ban’, which is a different pronunciation of the same characters. This ancient material, with a history in Japan stretching back hundreds of years, if not millennia, exploits the chemical properties of timber to make a rot and insect resistant layer of scorched material on the outside faces of timber boarding. By charring the timber with sudden and intense heat, the sugars in the timber are burnt away, stripping out the cellulose that bugs and fungus love to eat and leaving behind only the lignin, which is much more difficult to break down. The boards are quickly doused with water once the desired char has been achieved to stop them burning through completely. Traditionally, this was achieved by making a triangular tube out of three boards and stuffing it with straw or paper which was then set alight, but in modern times the same effect is achieved with kilns or blowtorches – the principal is the same but allows for more rapid production, though purists insist that these techniques are too fierce. When properly done, the charring can increase the longevity of the timber dramatically, with conservative estimates at around 80 years.

A Return to the Contemporary

It was Terunobu Fujimora who is widely credited with rescuing Shou Sugi Ban. After its heyday a few hundred years ago, this method of treating timber has been seen as a bit passé and provincial in Japan for much of the modern period, only really suitable for agricultural buildings, or in the most chocolate box of traditional villages. Part roving designer, part architectural historian, Fujimora reclaimed this ancient technique for use in contemporary buildings where its texture, practicality and stark, impenetrable tone is prized amongst modernists – but it didn’t all start recently.

One of Japan’s most famous architectural treasures, the Hōryū-ji temple near the ancient capital Nara was rebuilt in 670 AD after it burned down following a lightning strike. As if to prove the adage that lightning won’t strike twice, it obligingly hasn’t burned down again, meaning that it is currently winning the “world’s oldest building race” by a country mile at a stately 1,300 years old. When it was rebuilt all those years ago, naturally fire-retardant charred cedar was chosen to contrast with the traditional white stucco, the stripped back, monochrome palette emblematic of the design sensibilities of Japanese temple architecture and referenced millennia later in the humbug stripes of Fujimora’s Yakisugi House. Much of it is still there today, testament to the incredible durability of carefully chosen natural materials. Whilst we can’t guarantee that it’ll last until 3318 AD, timber has a proven track record as durable, versatile and attractive cladding.

In fact, Shou Sugi Ban’s wonderful texture and unique tones are now being noticed by designers and furniture makers, so whatever your project, why not get out the blowtorch, turn on the garden hose and get to charring! If you aren’t in the mood for a spot of pyromania, then new technology and products can help achieve Shou Sugi Ban’s qualities of deep tone, stability and durability in performance, without actually having to set anything on fire. Thermowood works on the same principle as Shou Sugi Ban, rendering the cellulose in the timber unpalatable to bugs and bacteria, but achieves it by baking the timber in an airless kiln so that there is no ignition. The result is a beautiful even tone and rich caramel scent, but more importantly stable, durable timber that will last a lifetime.

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