Closeup on slats of charred wood siding

Architectural trends do not always revolve around the newest ideas. Instead, they occasionally bring back the past by reviving ancient techniques with improved technology. 

An example of such a trend is using charred wood (Shou Sugi Ban).

The distinct dark appearance of charred timber siding is gaining interest in contemporary design. Keep reading for details on why charred wood siding is becoming popular, the pros, and the cons. We will also answer some common questions about charred wood siding.

What Is Charred Wood Siding? (Shou Sugi Ban)

Charred wood siding is an architectural design dating back to ancient Japan. It was used for wood preservation by charring it with a hot flame. The wood is developed using an oil finish to create a unique wooden exterior siding for residential homes.

It uses charred wood (Shou Sugi Ban) on your home’s exterior. Charring is a Japanese method of preparing wood for siding. The wood is charred at high heat, washed, and coated with natural, protective oil to make it fire-retardant, weather-resistant, and durable.

The wood is fed into a molder to create custom siding profiles. The profiles are then burnt, and varying char levels are applied. The outcome is a scorched wood finish with a spectacular gray or charcoal-black color. 

Fire is usually considered incompatible with wood because it causes wood degradation. However, Shou Sugi Ban enhances wood durability and preserves it naturally without paints, chemicals, and other treatments. It removes moisture and produces a chemical compound that protects the wood.

Charring the wood protects it from damage in the long term. It also blocks UV radiation. The wood surface can look like alligator skin, depending on the burn intensity. It can remain untreated or brushed and sealed with an oil.

In modern architecture, charred wood is often used for exterior siding. However, Shou Sugi Ban is an ancient technique that looks outstanding in rustic and contemporary designs.

A home utilizing Accoya charred wood siding
Courtesy of accoya

Why Charred Wood Siding Is Gaining Popularity

Charring timber was originally a wood preservation method. The ancient Japanese discovered that a deep, controlled burn could increase durability.

Here are some reasons why charred wood siding is becoming popular among architects:

Natural Durability 

The natural durability of charred wood makes it suitable for exterior siding. The damage that fire causes during the charring process strengthens the wood, making it an excellent choice for homes. As the wood burns, it creates a thin carbon layer, which you see as burnt food.

The carbon layer coats the wood interior as sealants or stains would. Charred wood siding is low maintenance and pest and moisture-resistant. It is even more effective on modified wood boards that are denser and more durable.

Two workers engaging in the Shou Sugi Ban burning process outside
Courtesy of Nakamoto Forestry

An Exceptional Alternative to Paints or Black Stains

With people increasingly seeking safe, natural ways of achieving beautiful interior designs, the ecology movement is expanding in the building design and architecture space. 

Charred wood siding gives your project an exquisite, dark finish without using toxic treatments that could harm people and the environment.

Staining or painting wood often covers the beauty of its natural grain. The treatments also require regular reapplication and maintenance and may contain toxic ingredients. Charred wood siding’s low maintenance and safety make it ideal for private and public spaces.

Simplifies Mixing Materials

Knowing what designs to mix, complement or contrast can be challenging. Charred wood simplifies this task because it blends with different materials to create numerous design styles. It adds a unique visual appeal to any property and enhances various designs.

Charred wood can work with marble, mirror, and metal to create a luxurious look. It can also work with wood of varying tones and stones to create a charming, rustic exterior. Whether you want a traditional, modern, warm or dramatic look, charred wood siding is versatile and will compliment your style.

Variety of Tones and Textures

Charring wood sounds simple, but there are different techniques, each producing different tones and textures. A thick char with a black color will work best if you are looking for something bold, with character and grit. For a design that requires a smoother finish, a brush char is ideal. 

Closeup on the texture of slats of charred wood siding

Each technique creates different tones on a single piece of wood while retaining the burning method’s durability and characteristics. However, some wood species have weak grain patterns that are overpowered by char and look dull after burning.

Limitless Designs and Patterns

Since charred wood is real wood siding, it offers limitless patterns and designs, making it an excellent material for creative siding. In addition, the various tones of charred wood add depth to complete the look. 

With charred wood siding, you can get your preferred look, whether you want to install narrow slats diagonally or wider slats horizontally.

Enhancing the Wood’s Natural Beauty

Charred wood is ideal for designs that need the distinctive nature of wood and a touch of intrigue. Charring methods highlight the natural grain to contrast with modern materials like glass and metal and complement traditional wood. 

Charing highlights the deep grain and creates a look that will have a lasting impression. Charred wood has superior qualities, and your siding will remain beautiful and last longer.

Pros of Charred Wood Siding

Installing charred wood sidings has several advantages. 

These benefits include:

It Is Waterproof

Wood is organic, and you have unlimited grains with thousands of varieties worldwide. It is solid and durable, and cutting and shaping it is relatively easy. However, wood is hygroscopic; it absorbs moisture from the air and contracts and expands in response to changes in moisture levels. 

Over time, wood can warp due to environmental factors, such as excess humidity. Modern wood protection techniques typically involve applying paints, oils, and varnishes. While these methods are highly effective, the coatings need regular reapplication to maintain their appearance.

A homeowner apply varnish to several two-by-fours

Charing the wood produces natural resins and creates a long-lasting barrier that protects wood from moisture. The wood is then coated using oil for extra resilience.

Insect Repellent

Wood is naturally susceptible to insect infestations. There are a few ways to mitigate this risk, but there isn’t a perfect way to prevent insects from burrowing into the wood. If you use charred siding, the oil finish provides you with greater protection, giving you the ultimate peace of mind. 

If you’re worried about mold, charred wood is an excellent option. The moisture levels in charred wood are too low for fungi or mildew to survive.

Better Durability and Fire Resistance

The charring process makes the wood more fire-resistant. It removes the soft cells on the surface that ignite quickly and leaves the rugged inner cells that require higher temperatures to burn. You can also add fire retardant if necessary.

Charring wood increases its strength, and removing the outer layer does not weaken the wood. On the contrary, the charring process draws out all moisture and produces stronger wood. 

More Aesthetic Appeal

Varying the burning and brushing process produces a variety of colors and looks, including a deep crackled look and a smooth, brushed appearance. 

The colors depend on how deep you burn and brush the wood. Depending on the type and charring process, you can get every imaginable tone, texture, or pattern.

Charred Accoya and Larch have strong grain patterns that produce a beautiful, unique finish. Cedar can be charred and gently brushed for a smooth appearance if you prefer a more traditional look. It can also have a heavy, grain-defining brush or a crackled, charred finish without any brushing.

Vertical slats of charred cedar wood

The versatility of charred wood makes it an ideal siding solution for various traditional and contemporary architectural styles. In addition, it retains its unique appearance because it is weather-resistant and does not fade like common wood.

Cost Efficiency

Charred wood costs less, and your project will progress faster since it doesn’t require painting. You can also select the wood type and charring level depending on the use. It is less costly than other types of siding and produces a unique appearance that can last for decades.

The most significant advantage of charred wood siding is its endurance. It is weather and pest-resistant; therefore, recurrent maintenance costs are minimal. Once it reaches its lifespan, it can be disposed of or recycled and used as reclaimed wood.

The char layer can go up to 100 years without any maintenance. The wood might not require refinishing for up to 15 years because it doesn’t fade or peel over time. Oil the siding once every decade, and your home remains protected for 100 years.

Environmental Sustainability

Charring is a natural, non-toxic wood preservation technique that does not contribute to pollution. It has no chemicals and is safe for homes, children, and pets. It is also pest-resistant, meaning no need for chemical repellents.

Charring wood is a sustainable way of protecting wood on exterior siding. Homeowners can combine it with other eco-friendly materials for doors for environmentally sustainable living spaces.

Closeup on a subdued grain bamboo door

Cons of Charred Wood Siding

While charred wood has many advantages, it also has its downsides.

These drawbacks include the following:

  • High initial costs – manufacturing charred wood siding is more costly than other types. While maintenance costs are low, the initial production and installation cost is higher than that of other siding materials.
  • Charring requires specialized equipment – learning how to use the equipment can be challenging, and the process is also a safety hazard. It requires extreme caution because it can cause severe injuries.
  • Labor intensive and time-consuming– charring wood takes time and effort to master. The process also takes significant time to complete depending on how much wood you need. It is also tiring and messy.
  • Inconsistent finish – every piece of charred wood is different, which gives this siding a unique appearance. However, this type of siding is unsuitable for someone looking for a uniform finish.

Best Wood for Charred Siding

Professionals favor some types of wood for siding. The woods can withstand the high temperatures necessary for charring.

  • Cedar: Cedar is a hardwood traditionally used in wood charring and is solid enough for all exterior projects. It can withstand temperature changes, rain, and insects and is beautiful when charred. Its chemical properties work well with charring techniques to produce an appealing final product.
  • Accoya: Accoya is a contemporary, sustainable type of wood with exceptional versatility. It does not shrink or swell during the charring process or require continuous maintenance. Due to its durability, its initial cost is high, but long-term care is low.
Charred Accoya siding on a home's exterior
Courtesy of Exterior Solutions
  • Pine: Compared to other types of wood, pine is a soft wood that offers the aesthetics of charred wood at a lower cost. It is straightforward to oil and has an amazingly smooth finish but lower heat resistance. However, it also requires frequent attention and maintenance compared to hardwoods, and the boards are short.
  • Spruce: Similar to pine, spruce has lower resistance to the elements—it requires regular inspections and oiling to keep water out. It is ideal for someone who loves the look of pine but needs longer wood planks for siding.
  • Larch: Larch is highly stable, exceptionally decay-resistant, and very dense. It has a clean, smooth finish like pine and spruce, but it costs more. It is the perfect choice if you want wood with a more natural look.

Charred Wood Siding FAQ

Here are a few common questions about charred wood siding so you can make an informed decision about whether it’s right for you.

Must You Oil Charred Wood Siding?

Oiling is optional and is usually done for three main reasons:

  • Binding the soot
  • Bringing out the desired color
  • Maintaining the color longer

Oiling also gives your siding a shiny, fresh, new look all year round. Oiling is typically done when the wood is manufactured, but you can also use oiling as a maintenance method over the years.

What Type of Wood Can Be Charred for Siding?

The types of wood that can be charred for siding include:

  • Cedar
  • Oak
  • Cypress 
  • Spruce
  • Pine
  • Accoya 

While some softwood, such as the last three on this list, are suitable for charring, some softwood shrinks during the charring process, so it is better to dry them first.

Stained wood should not be charred because the heat will cause blistering and peeling of the stain. Instead, paint the wood with heat-resistant paint to achieve a similar finish.

How Does the Appearance of Charred Wood Weather Over Time?

Like natural wood, charred wood forms a patina over time. There is an element of control here, and you can use oil to change the appearance if you like. 

Closeup on the patina texture of some charred wood lumber

However, most people like the idea of the charred wood developing an aged finish over time, so oiling isn’t necessary as part of maintenance. 

Will the Charred Finish Be Shed Due to Weather Exposure?

Most charred wood sidings have an oil coating that bonds the soot to prevent it from shedding when touched. You’ll probably have to clean any excess away after fitting the siding. 

Some woods with tannin (like hardwoods) can experience damage due to exposure to the elements. This damage might require a bit of cleanup since you might find the wood ‘weeps’ to some extent – but you should be able to fix this quickly.

Final Thoughts

Charred wood siding is visually-appealing, reliable, and energy-efficient. It is a non-toxic, environmentally-friendly way to offer your home an all-natural appearance. Its popularity has recently increased as more people seek an affordable alternative to classic siding.


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