Does Burning Wood Seal It?

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Burning wood is a technique that can indeed enhance its durability and strength, but the question remains: does it actually seal the wood?

To help you navigate through this process safely and informatively, I’m here to explain the critical elements of wood burning and provide clarity on whether or not this method effectively seals the wood.

Does the Burning of Wood Preserve the Wood?

Using burnt or charred wood is one of the many alternative methods for protecting wood against deterioration.

The method of burning wood, also known as Yakisugi, is a traditional Japanese practice that involves charring the wood’s surface. This serves as a safeguard against weather and insect damage, while also imparting a distinctively attractive look to the final wood product.

When the wood is burned, a char layer is created on its surface, which functions as a sealant, preventing water from penetrating and safeguarding it from rot. So, burning wood enhances its durability, allowing it to maintain stability for an extended period.

burning wood

Besides offering exceptional water resistance, burning improves the wood’s defense against UV rays, insects, fire, and fungus. It also imparts a distinctive appearance of reddish-brown or black to your wooden furniture and wood project.

Typically, burnt or charred wood has a lifespan of twelve to fifteen years and does not require any maintenance during this period. Charred wood does not require yearly sealant re-application, unlike regular wood.

While burnt or charred wood can indeed hold up in outdoor settings, I want to emphasize the importance of applying a sealant before subjecting it to the elements. 

It’s crucial to understand that burnt or charred wood doesn’t quite match the resilience of wood treated with top-notch sealants, and without adequate protection, it may not stand up to harsh weather conditions.

Can Burning Wood Be Beneficial In Making It More Resistant To Water?

By burning wood, you can enhance its resistance to water, ensuring its durability over an extended period. However, it is crucial to note that burning wood does not make it completely waterproof.

wood burning

Instead, it simply prevents water from seeping into the wood and increases its resistance to water. Applying a waterproof sealant to the wood is necessary to achieve waterproofing. So, below are excellent waterproofing sealants for your wooden pieces.

The primary role of wood sealers is to hinder water absorption of the wood, thus preventing it from contracting or expanding due to moisture. Similarly, burning wood solely enhances the wood’s resistance to water, making it beneficial to use charred wood in humid environments.

Despite possessing excellent water resistance, wood can still undergo visible expansions and contractions due to fluctuations in temperature and humidity.

Coating burned or charred wood with a sealant protects it against weather elements, including water damage, humidity fluctuations, and moisture. This makes it a desirable option for outdoor woodworking ventures.

heating up the wood

Before application, it is critical to test the compatibility of the sealant with the burned or charred wood since some sealants may not adhere well to its surface. Below are manageable steps to achieve waterproof burnt wood by applying an appropriate sealant.

Is Burnt Wood a Food Source for Termites?

Termites consume wood that has been burned, despite their aversion to inhabiting it as their living space.

However, if termites feed on the charred parts of the wood that contain lignin [1], they may either fall ill or perish. Termites still consume burnt wood, and there may be a distinct flavor that only termites can detect from burnt wood.

Despite exposure to an open flame, certain species of termites can survive within wood surfaces with a moderate burning level. While others have high heat tolerance and can live in wood that the fire has not severely impacted.

burning some wood holes

The warm environment provided by burnt wood makes it an ideal place for certain insects and termites to lay their eggs, which is why they are attracted to it.

Using a high-quality sealant and regularly cleaning burnt wood is crucial for long-term protection against termites, even though burnt wood is more susceptible to termite infestation than fresh wood.

Can Burning Wood Prevent It From Rotting?

When the wood is exposed to fire for a duration sufficient to create a layer of charred wood on the surface without damaging its structure is referred to as burnt or charred wood.

The carbon char layer protects against decay and provides water resistance to the wood, giving it more resilience to water penetration than regular lumber. The combination of reduced water penetration and the protective carbon layer significantly enhances the overall resistance of the wood.

However, while resilient in outdoor settings, charred wood remains susceptible to moisture and water particles during rainy days or extreme weather conditions. As the char layers contain gaps, these elements can infiltrate the wood and get trapped beneath its surface.

burning softwood

If left unaddressed, extended exposure to moisture can cause rot to develop from within, compromising the wood’s structural integrity.

Thus, if you detect rot in charred wood, applying a high-quality product like Flex Seal to restore the wood is important. You can use Flex Seal on rotted wood to prevent further rotting and creates a waterproof layer to prevent future moisture penetration.

In addition, this ensures that burned or charred wood remains protected from deterioration when used in outdoor projects. It is imperative to use a sealant to block moisture absorption.

Does Burning Wood Make it More Durable?

Burning wood can provide a two-fold benefit of increasing its strength and protecting it from weather elements. Applying heat to lumber during a fire causes the wood grains to bond more tightly, resulting in a tougher and more durable board.

Burning the wood enhances its flexural and compressive strength, resulting in a stronger material overall.

wood burning

When the wood is treated with a strong burn, it can withstand heavier loads without jeopardizing its stability, which ultimately prolongs its lifespan compared to untreated wood.

However, if the wood is left in the fire for an extended period, it will gradually break down and develop burns, cracks, and scorch marks.

Burning wood can be useful to increase its strength and durability. Still, it should be coupled with additional protective measures such as wood sealant to maximize its potential benefits.

Is Wood Hardened by Burning It?

When burned, the wood undergoes annealing, making it softer and more pliable than hardening. Exposure to an open flame may cause the wood to become slightly fragile and feeble.

The intense heat causes the wood fibers to break down, reducing their structural integrity. So when burning wood, avoid excessive charring or overheating, which can cause irreversible damage and compromise strength.

burnwood darkening

However, fire hardening is one of the traditional and effective ways to strengthen the wood. Although it may seem contradictory, this method involves heating up softwood directly in a bed of coal or fire.

The heat from the fire eliminates excess moisture from the grains of the wood, which tightens the wood fibers and strengthens the weaker parts of the wood.

Properly burned wood can be durable and long-lasting for various applications. Still, care must be taken to ensure the burning process is done correctly to avoid compromising its structural integrity.

Benefits of Charring Wood

Burning wood can offer a multitude of benefits for both indoor and outdoor woodworking projects and furniture. It becomes more resistant to weather elements like moisture and water damage, resulting in a longer lifespan.

Burning or charring wood offers exceptional durability, its most significant advantage. It provides impressive protection against pests such as termites and ants.

burning wood egdes

Maintaining burnt or charred wood is economical since you only need to apply oil once every decade, and replacement is not a concern. Charring wood can provide numerous advantages, making it a worthwhile option for woodworking projects.

Below are exceptional benefits that can be gained by burning wood for your woodworking pieces.


Do you have to seal the wood after burning?

Yes, you have to seal the wood after burning. To protect your surface, it is necessary to apply a wood sealer if you are not covering it with paper or fabric. Also, allowing the sealer to dry completely is crucial, regardless of your chosen type or brand.

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While burning wood can provide a level of surface sealing and does indeed enhance the material’s durability, strength, and resistance to pests and weather elements—not to mention its aesthetic appeal—it is not a foolproof safeguard against extreme damage.

To truly seal wood effectively, it is imperative to apply a wood sealer and allow it ample time to dry completely. Taking into account the intended use of the wood is crucial, as it enables you to choose the most suitable sealing method, ensuring the wood’s longevity and performance over time.

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Robert Johnson is a passionate furniture maker & carpenter, sought after for his knowledge on the craft.
You’ve probably seen his down-to-earth wisdom in USA Today, Bobvila, Family Handyman, and The Spruce, where he has shared commentary and guidance on various woodworking topics.

Robert is the brain behind Sawinery, where he aims to share tips, tricks, and a passion for all things carpentry.

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