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  • What Is The Shou Sugi Ban Wood Preservation Process?

    What Is The Shou Sugi Ban Wood Preservation Process?

    For centuries, carpenters and builders have explored methods to preserve wood. While many preservation techniques were abandoned as new processes were developed, some techniques have stood the test of time.

    The Japanese shou sugi ban wood burning technique uses an open flame to charr the wood's surface, preserving it from the elements. The technique first became popular in 18th century Japan, but has earned a Western resurgence in recent years.

    The History of Shou Sugi Ban Wood Preservation

    Historically, wood preservation was an important process. Many different techniques arose, including white washing and kiln drying.

    Many cultures have experimented with and incorporated wood charring into their preservation techniques. It’s believed Japanese carpenters first experimented with wood charring after observing the durability of driftwood. The exact origins of the process are uncertain, but likely stems from boat building practices. However, it became a crucial process during Japan’s Edo period (1603-1867).

    During the Edo period, Japan experienced significant economic growth. Major Japanese cities underwent periods of rapid urbanization. The construction of dwellings, temples, and many other buildings became necessary. 

    Shou sugi ban wood was at its peak use in Japan’s Edo period. Japanese carpenters carefully charred thin planks of Japanese cypress (known as sugi) under intense heat. After the planks were charred and treated, they were used as exterior siding. This was an effective, cost-efficient way to help weatherize buildings. 

    Soon the characteristically dark, charred-wood exterior and light stucco appearance of Japanese exterior architecture became prevalent.  

    How Does Shou Sugi Ban Preserve Wood?

    Like any charring technique, the shou sugi ban process involves three major steps:

    1. Charring the lumber’s mostly-cellulose surface
    2. Scraping to remove excess char
    3. Applying a natural oil finish

    Each of these steps contributes to the wood’s preservation. Generally, the outer layer of wood is composed mostly of softer cellulose. The outer layer of cellulose is where many fungi grow and insects harbor. When the wood is charred and then scrapped, this cellulose layer is stripped away. 

    What’s left under the removed cellulose is the more rigid lignin layer deeper within the wood. This layer is more durable and resistant. The remaining carbon char also acts as a protective coating, both repelling water and making it flame resistant. 

    Finally, a natural oil finish, most commonly linseed oil, is applied to the shou sugi ban wood. The oil acts as a final water-repellent layer and helps “seal” the carbon layer underneath, further increasing its longevity.  

    What Are The Benefits of Shou Sugi Ban?

    Charred wood offers many benefits to homeowners - from sustainability to the look and feel of the finished wood.

    Chemical-free Preservation

    Charring wood is a chemical-free preservation method. Modern lumber is often treated with chemicals that act as preservatives and fire retardants. However, these chemicals can pose health risks and harm the environment. By comparison, charred wood is a safer and more environmentally friendly alternative to many preservative treatments and chemical finishes. 

    Sustainable Home Exterior

    Modern homes often use vinyl siding as an exterior. Vinyl is a popular choice because it’s insect and decay resistant while also easy to clean. However, vinyl siding is harmful to the environment:

    Wood is a significantly more sustainable siding option. It’s a renewable resource and will decompose without harming the surrounding environment.

    Increased Flame Resistance & Durability

    Shou sugi ban wood offers a high level of durability. By charring the wood’s surface and finishing it with an oil, it becomes naturally water and rot resistant. The charring process also makes the wood less appealing for insects. 

    In addition, the char on the outside of the wood is flame resistant and slows the rate of burning. While more research must be conducted to determine exactly how flame resistant charred wood really is, it is more protective than untreated lumber. 

    Naturally Beautiful Aesthetic 

    Because shou sugi ban wood can be used as home siding, it offers a unique home aesthetic that can’t be matched by vinyl or other artificial exteriors. Dark tones and visible wood grain patterns make for a natural look and feel that many homeowners appreciate. 

    It can be used indoors, as well. Charred wood makes beautiful interior paneling and richly hued wood furniture or home decor that is long-lasting and unique. 

    Why Has Shou Sugi Ban Wood Become Popular Again?

    Shou sugi ban wood was only recently “rediscovered” outside of Japan and has seen a rise in popularity over the last decade. The most significant reason for its resurgence is a growing interest in sustainability. 

    While many people appreciate shou sugi ban wood simply for its unique aesthetic, as mentioned, charring wood is a chemical-free preservation method. As builders, home designers, and homeowners search for sustainable building materials and construction methods, older techniques, like shou sugi ban wood charring, provide an environmentally sound solution. 

    Why We Use Charred Wood For Our Shelves

    At Urban Legacy, we appreciate the rich history of wood construction. We use reclaimed wood to create unique shelves for homes. It’s our belief that the character of reclaimed wood tells a unique story and preserves a sliver of history that would otherwise be lost to time when an old structure is torn down.

    When we began crafting modern wood shelves, we searched for traditional methods of wood preservation. After discovering the tradition of shou sugi ban wood and flame treatment, we knew we wanted to offer the same care and craftsmanship to our customers.

    Our low profile torched oak and fully bracketed torched oak shelves use chemical-free wood charring and plant-based finish to create a deep hue that highlights the grain of quality oak. Shop our made-to-order shelf options or contact us for a free custom shelving quote.