What Is Modified Wood Decking? (Cost, Lifespan & Process)

Modified wood decking is lumber heated to 356-419°F in an oxygen-starved chamber (thermal modification) or chemically altered through acetylation or furfurylation, so it resists rot and insects for 25 to 30 years without pressure-treated wood’s copper-based chemicals. Species matters: thermally modified ash costs roughly $4.50 per square foot versus about $2.40 for pine, and acetylated Accoya runs $8 to $15 per linear foot. This guide covers how each process works, real cost comparisons, and which option is worth the extra cost.

Thermally Modified Wood

Thermally Modified Wood Decking offers enhanced durability and longevity through a specialized heating process that alters its properties. This innovative technique provides a natural alternative to chemical treatments for decks, ensuring a sustainable and eco-friendly choice for outdoor spaces.

Durability

Thermally modified wood offers exceptional durability due to the thermal treatment process altering its cellular structure.

Thermal Modification Process

The thermal modification process involves heating the wood in a controlled environment to enhance its properties.

Profile

The profile of thermally modified wood decking showcases a unique blend of natural aesthetics and enhanced strength.

Maintaining Tone

Maintaining the tone of thermally modified wood decking is relatively easy with proper care and periodic treatments.

Seasonal Maintenance

Seasonal maintenance for thermally modified wood decking involves regular cleaning and protective coatings to prolong its lifespan.

The Modification Process: Temperature And Species

Thermal modification uses pyrolysis — heating wood to 356-419°F (180-215°C) in an oxygen-starved chamber for several hours, which drives off the hemicellulose sugars that fungi and insects feed on. Ash, spruce, and pine are the species most commonly thermally modified for decking. Chemical modification works differently: Accoya uses acetylation (an acetic-anhydride bath) on radiata pine, while Kebony uses furfurylation, impregnating southern yellow pine with a bio-based liquid derived from sugarcane waste. Both change the wood’s cell structure permanently rather than coating the surface, which is why neither needs the sealing that untreated wood requires.

Advantages And Disadvantages

Thermally modified wood is gaining popularity as a sustainable option for decking. It goes through a thermal modification process that enhances its durability and stability. However, like any other material, it also comes with its advantages and disadvantages.

Advantages Of Thermally Modified Wood

• Enhanced durability: Thermally modified wood is highly resistant to rot, decay, and insect damage, making it a long-lasting option for decking.
• Increased stability: The thermal modification process reduces moisture content in the wood, minimizing swelling and shrinking, which can lead to warping and cracking.
• Natural beauty: Thermally modified wood retains its natural colors and patterns, offering an aesthetically pleasing option for decking.
• Chemical-free: Unlike pressure-treated wood, thermally modified wood does not require chemical additives to enhance its durability, making it an eco-friendly choice.

Disadvantages Of Thermally Modified Wood

• Decreased flexibility: The thermal modification process can make the wood more brittle, limiting its flexibility for certain applications.
• Challenging saw cuts: Due to the dryness of thermally modified wood, achieving clean and precise cuts can be more difficult. It requires a sharp blade and careful handling.
• Higher cost: Thermally modified wood decking can be more expensive compared to traditional wood options.
• Limited availability: Although the demand is increasing, thermally modified wood may not be as readily available as other decking materials.

“Thermally modified boards are noticeably lighter and drier than pressure-treated lumber of the same dimension — in the shop we’ve found they cut clean with a sharp carbide blade but tear out badly with a dull one, since there’s no moisture left to keep the fibers from splintering.”

Comparison With Pressure-treated Wood

When comparing thermally modified wood with pressure-treated wood, there are some noticeable differences. While pressure-treated wood is chemically treated to enhance its durability, thermally modified wood achieves its durability through a natural thermal modification process.

One key difference is the appearance. Pressure-treated wood may have a slight green tint due to the preservatives used, whereas thermally modified wood retains its natural caramel color. With time, pressure-treated wood may fade to a natural tan color.

Additionally, thermally modified wood offers the advantage of being chemical-free, making it a more sustainable and environmentally friendly option compared to pressure-treated wood.

Although thermally modified wood has its advantages and disadvantages, it is ultimately a versatile and durable option for decking, especially for those looking for a natural and eco-friendly material.

Environmental Benefits

Modified wood decking offers numerous environmental benefits compared to traditional wood options. By undergoing thermal or chemical modifications, the characteristics of the wood are enhanced, resulting in enhanced durability and improved resistance to decay and insect damage. This eliminates the need for chemical treatments and preserves the natural beauty of the wood, making it a sustainable and eco-friendly choice for decking.

Natural Bio-based Liquid Vs. Chemical-based Products

When it comes to the environmental benefits of modified wood decking, one key factor to consider is the choice between natural bio-based liquid and chemical-based products. Unlike traditional decking materials that are loaded with chemical-based products, modified wood, such as Kebony, uses a natural, bio-based liquid to achieve its superior performance characteristics. This makes it a much more environmentally friendly option.

Chemical-based products used in traditional decking materials can have negative impacts on the environment. These chemicals may leach into the soil and waterways, causing harm to plants, animals, and even humans. In contrast, the natural bio-based liquid used in modified wood is derived from sustainable sources and does not pose the same environmental risks.

The benefits of using a natural bio-based liquid in modified wood decking include:

• Reduced carbon footprint: The production of natural bio-based liquids has a lower carbon footprint compared to the manufacturing of chemical-based products. This contributes to a more sustainable and eco-friendly decking option.
• Renewable materials: Natural bio-based liquids are derived from renewable sources, such as plant-based oils. These materials can be easily replenished, ensuring a more sustainable decking choice.
• Less toxicity: Chemical-based products often contain harmful toxins, such as volatile organic compounds (VOCs). Natural bio-based liquids, on the other hand, have lower toxicity levels, reducing the negative impact on indoor air quality and overall environmental health.
• Better long-term performance: Modified wood decking with natural bio-based liquids has been proven to have superior performance and durability compared to chemical-based alternatives. It can withstand harsh weather conditions, resist rotting and decay, and maintain its beauty for longer periods of time.

Conclusion

Choosing modified wood decking with a natural bio-based liquid offers numerous environmental benefits. It reduces the carbon footprint, utilizes renewable materials, minimizes toxicity, and provides long-term performance. By opting for this sustainable decking option, you can enjoy a beautiful outdoor space while also making a positive impact on the environment.

Longevity And Maintenance

When it comes to selecting decking material, longevity and maintenance are crucial factors to consider. Modified wood decking, particularly thermally modified wood, offers unique benefits in terms of durability and upkeep. Let’s delve into the lifespan and maintenance aspects of thermally modified wood decking.

Lifespan Of Thermally Modified Wood

Thermally modified wood boasts a lifespan of roughly 25 to 30 years depending on species and finish upkeep, making it a durable choice for decking projects. The thermal modification process enhances the wood’s stability and resistance to decay, prolonging its lifespan compared to traditional wood options.

Comparison Of Maintenance With Other Wood Options

When it comes to maintenance, thermally modified wood requires minimal upkeep compared to other wood options. Here’s a breakdown of the maintenance comparison:

Aspect	Thermally Modified Wood	Other Wood Options
Regular Sealing	Not required	Often needed
Resistance to Decay	Highly resistant	May need frequent treatments
Color Retention	Maintains tone well	May require staining or painting

• Modified wood decking eliminates the need for regular sealing, reducing maintenance tasks.
• Thermally modified wood exhibits high resistance to decay, minimizing the need for frequent treatments.
• The wood maintains its tone well over time, reducing the necessity for staining or painting.

Overall, thermally modified wood decking offers a longer lifespan and lower maintenance requirements compared to traditional wood options, making it a sustainable and cost-effective choice for outdoor projects.

How Much Does Modified Wood Decking Cost?

Modified wood decking costs more upfront than pressure-treated lumber, but the premium varies widely by process and species. Thermally modified ash runs about $4.50 per square foot in board form, while thermally modified pine is closer to $2.40 per square foot. Chemically modified options cost more: Kebony decking has been listed around $9.68 per linear foot, and Accoya runs roughly $8 to $15 per linear foot depending on profile and thickness.

Decking Type	Approx. Cost	Best For
Thermally modified pine	~$2.40/sq ft	Budget-conscious upgrades from pressure-treated lumber
Thermally modified ash	~$4.50/sq ft	Higher density and a darker, more uniform tone
Kebony (furfurylated)	~$9.68/linear ft	Longer 30-year durability claims and a hardwood look
Accoya (acetylated)	$8-$15/linear ft	Maximum dimensional stability, including ground-contact use

These figures are material costs only, before installation, and shift with board width, thickness, and profile — use them as a starting comparison, then run your own square footage through a decking cost calculator for a project-specific number.

📊 Thermally modified ash and pine pricing reflects supplier listings compiled in early 2024. Source: AdvantageLumber Deck Cost Breakdown, 2024

Popularity And Availability

Modified wood decking has recently gained significant popularity due to its enhanced durability, sustainability, and unique aesthetic appeal. This eco-friendly alternative to traditional decking materials has become increasingly sought after by homeowners and builders alike. Additionally, the availability of various brands and suppliers offering modified wood decking has contributed to its growing demand in the market.

Rising Popularity Of Modified Wood Decking

The rising popularity of modified wood decking can be attributed to its eco-friendly nature and exceptional durability. With a growing emphasis on sustainability and environmental consciousness, consumers are increasingly seeking decking materials that offer long-term benefits without compromising the environment. Modified wood, which undergoes thermal or chemical treatments to enhance its properties, has emerged as a favored choice for eco-conscious individuals seeking durable and aesthetically appealing decking solutions.

Available Brands And Suppliers

Several reputable brands and suppliers offer a wide range of modified wood decking products, providing customers with diverse options to suit their specific preferences and project requirements. These include renowned manufacturers such as Arbor Wood Co., Kebony, and others, which specialize in producing high-quality modified wood decking materials. Furthermore, numerous suppliers distribute these products, ensuring accessibility and availability in the market. For homeowners comparing all wood decking options, it’s worth noting that modified wood competes directly with composite decking on the low-maintenance argument — but unlike composite boards such as Trex, it’s still real wood that can be sanded, oiled, or refinished rather than only cleaned.

Sustainable Decking

When it comes to decking, sustainability is a key factor to consider. Modified wood decking offers a sustainable alternative that not only enhances the visual appeal of the outdoor space but also minimizes the environmental impact. In this section, we will delve into the sustainability of modified wood decking and explore its chemical-free attributes.

Sustainability Of Modified Wood Decking

Modified wood decking is renowned for its sustainable properties. The thermal or chemical modification process enhances the wood’s natural characteristics, resulting in a product that is resistant to decay, insect damage, and moisture. This increased durability prolongs the lifespan of the decking, reducing the need for frequent replacement and minimizing overall environmental impact.

Furthermore, many manufacturers source responsibly managed forests for their raw materials, ensuring that the production of modified wood decking contributes to forest conservation and supports sustainable forestry practices.

Frequently Asked Questions On What Is Modified Wood Decking

What Is The Difference Between Wood And Modified Wood?

Modified wood differs from standard wood by being thermally or chemically altered to enhance its properties.

What Are The Disadvantages Of Thermally Modified Wood?

The disadvantages of thermally modified wood include reduced flexibility and difficulty in achieving a beautiful saw cut due to dryness. It requires a sharp blade, and some find its caramel color to be a downside.

How Long Does Thermally Modified Wood Last?

Thermally modified wood can last up to 25 years due to the enhancement of its properties through a thermal or chemical process. It is a durable and long-lasting option for decking or any other outdoor applications.

What Is The Difference Between Pressure-treated Wood And Thermally Modified Wood?

Pressure-treated wood has a green tint, while thermally modified wood retains a natural caramel color. The difference lies in the treatment process – chemicals for pressure-treated, thermal or chemical changes for modified wood.

Is Modified Wood Decking Worth The Extra Cost?

For most homeowners keeping a deck 15 or more years, yes — thermally modified pine at roughly $2.40 per square foot costs only slightly more than pressure-treated lumber but skips the copper-based chemical runoff and needs no sealing. Acetylated or furfurylated options like Accoya and Kebony cost significantly more and make the most sense for ground-contact applications or harsh climates where 30-year durability justifies the premium.

Conclusion

Modified wood decking offers a range of advantages over traditional wood decking options. With its enhanced durability, resistance to rot and decay, and improved dimensional stability, modified wood is a smart choice for decking projects. The thermally or chemically modified characteristics of this type of wood enhance its performance and longevity, making it a reliable and long-lasting option.

In addition, modified wood decking is environmentally friendly, as it often uses natural, bio-based liquids instead of harsh chemicals. Budget for roughly $2.40 to $15 per square or linear foot depending on species and process, and consider opting for modified wood decking to create a beautiful and sustainable outdoor space.