Shou sugi ban refers to the final product rather than the process of charring the wood. Hint: Use it as a noun and not a verb or adjective. You may have never heard the term, but you may have seen examples of it without knowing what it was. The phrase is pronounced show as in shower, soo as in Sue, jee as in gee, and ban as in... ban.
The technique is labor intensive, but the results are amazing, producing a dark color that stands the test of time. You may want to consider using this centuries old product to add a unique touch to the exterior or interior of your home.
What Is It?
The term shou sugi ban is a result of mistranslation of the term yakisugi. In Japanese, yaki means charred or burnt, while sugi refers to the wood—specifically the Sugi Cypress, also called Japanese Cedar—traditionally used for the product. Shou sugi ban combined Chinese and Japanese pronunciations of yakisugi, and has become the more common term in the west for the heat-treated wood.
This ancient form of preservation is gaining popularity around the world, since the methodical process of drying, burning, and quenching turns the surface of the wood a rich ebony color that's waterproof, durable, and requires little maintenance.
How Is It Made?
It begins with proper wood selection. Sugi Cypress is endemic to Japan, so in the west, cedar which can be procured more easily is also used. Its light and porous characteristics make it an ideal material for making shou sugi ban, but it can also be done with pine, maple, or oak.
The wood must be properly dried before the intense heat treatment. Air drying is preferred over kiln drying. Once completely dry, the wood is fed into a contained fire and monitored closely to ensure it is quenched at just the right moment before it is completely incinerated. It can also be heated by hand, but that approach requires more experience.
After heat treating, the wood is dried once again and is ready for use as-is. At this stage, the wood will have a characteristic cracked appearance like what you'd see in a log burning in a fireplace or campfire. Other options exist if you're not into the rustic look of the coarse surface.
The surface charcoal can be brushed away to reveal a lighter color and the fine pattern of the wood grain underneath. Depending on your preference, a second brushing can also be done to better reveal the beauty of the wood patterns.
Once the desired surface is achieved, the wood must be coated with linseed oil to create a seal against the elements for proper weatherproofing.
What Is It Used For?
This versatile material has myriad uses. Traditionally it was used for exterior siding and shipbuilding, but the modern creative DIYer can figure out many ways to incorporate this durable material on both the exterior and interior of their homes.
Outdoor furniture made with this wood is extremely beautiful with its warm, rich tones. Exterior siding, decks and railings, interior accents, furniture, and shelving are only some of the places shou sugi ban can be used.
Why Use it?
Beauty is in the eye of the beholder, so if you love the vibe of dark wood, this look is a definite head turner. If you’re only so-so on the aesthetic appeal of shou sugi ban, consider another reason to love it: its durability and nearly maintenance free lifespan. Cedar is a long-lived material, and subjecting it to the heat treating process makes it even more so. Charring the surface minimizes the cellulose that would normally attract damaging insects. The resulting layer of soot increases its resistance to fire, due to the heightened threshold needed for combustion.
In its original unbrushed state, shou sugi ban resists weathering, helping it hold its color for 40 years or longer, depending on the quality of the burn and the conditions of the site. On the other hand, brushed shou sugi ban will be susceptible to weathering like any other wood and will require periodic oil treatment every few years to maintain its waterproof capability and keep it looking its best.