Thermally Modified Wood (TMW): Building a Smarter, Stronger, and More Sustainable Future for North American Hardwoods

Have you heard about Thermally Modified Wood (TMW)? If not, now is the perfect time to learn. Whether you’re a sawmill operator, product distributor, builder, designer, or policy advocate, TMW could be a big part of our future.

Thermal modification takes natural wood and enhances it through a special heat-based process. It is more durable, more stable, and darker than the natural species. Most importantly, it offers a sustainable, chemical-free solution for a growing market that wants less tropical wood and better performance, aesthetics, and environmental responsibility from domestic species.

Across North America, we are at a turning point. The TMW industry is growing but still faces significant awareness, coordination, and product consistency gaps. That is why the National Hardwood Lumber Association (NHLA) leads a unified industry effort to build standards, best practices, and a strong foundation for long-term success. To do that, we need your help.

This article will explain TMW, why it matters now, the challenges we must overcome, and how all stakeholders can shape the future. This article is for anyone in the TMW value chain who’s ready to help lead the charge toward a smarter, more sustainable future.

WHAT IS THERMALLY MODIFIED WOOD?
Thermally Modified Wood is real wood heated to high temperatures (usually between 350°F and 430°F) in a low-oxygen environment. This process changes the cellular structure of the wood without adding chemicals or pressure treatments.

The results are impressive:

• Enhanced dimensional stability
• Lower equilibrium moisture content
• Increased resistance to decay
• Richer, darker color with a more consistent surface
• Longer life in outdoor and humid environments

TMW can be used in many applications such as decking, siding, cladding, furniture, flooring, and interior finishes. It offers a high-performance alternative to tropical hardwoods and pressure-treated products.

WHY NOW IS THE RIGHT TIME FOR TMW
North America has an abundance of underused hardwood species. However, many of these species have lost domestic market share over the last two decades. This is partly due to changes in design trends, increased non-wood substitutes, over dependence on exports, and the fact that inexpensive imports are returning.

The entire industry feels shock when international demand drops or trade policies shift. That is why more producers, architects, and suppliers are looking for ways to create stable, local demand for North American hardwoods.
TMW offers a new path. It adds value to common species like red oak, ash, maple, and poplar. It makes softwoods like pine and spruce more useful for outdoor use. It aligns with green building goals. It also gives designers beautiful material that meets modern performance standards.

However, the potential of TMW will only be realized if we work together to solve the current challenges.

THE CHALLENGES WE MUST OVERCOME
TMW has not yet reached full commercial maturity in North America despite its benefits. Adoption is growing, but the industry is still fragmented. Many buyers are unsure what they are getting. Many suppliers do not fully understand what the processors need. Many architects are unaware of their capabilities.

Here are the most significant issues holding back the market:
1. No unified product standard
There is no widely accepted performance standard for TMW in North America. Without one, it is hard for buyers to compare products or trust consistency. This creates confusion and slows adoption.

2. Lack of awareness and education
End users, including builders, designers, and contractors, often do not know how TMW performs, how to use it, or where to find it. Misunderstandings about durability, availability, and cost are common.

3. Disconnected supply chain
Lumber suppliers may not know what thermal modifiers need regarding species, grading, or moisture content. This results in raw materials not optimized for modification, leading to lower quality products.

4. Inconsistent product quality
Because different manufacturers use different systems, feedstocks, and processing methods, final product quality can vary widely. This creates distrust in the market and generates risk for buyers.

5. Limited policy support
TMW is often not mentioned in building codes, sustainability certifications, or public procurement programs. That makes it harder to specify, promote, and grow at scale, while tropical species are given a free pass regardless of their sustainability or durability.

A NEW EFFORT TO BUILD ALIGNMENT AND TRUST
The NHLA has created a dedicated TMW Task Force to address these challenges. The group consists of professionals from across the industry who work together to:

• Develop performance-based product standards
• Build technical guidance for processing, grading, and testing
• Educate end users and decision-makers
• Advocate for the inclusion of TMW in codes and green building programs
• Promote the value and potential of TMW to new markets

The goal is to create a shared framework that supports growth, consistency, and collaboration. That includes producers, equipment suppliers, distributors, architects, policy leaders, researchers, and beyond.

LISTENING FIRST: WHY THE TMW SURVEY MATTERS
Before creating solutions, we must understand the real needs of the industry. That is why NHLA launched the 2025 TMW Stakeholder Survey. This survey collects insights from the supply chain – from raw material suppliers to product distributors and technology providers.

It asks questions like:

• What equipment do you use?
• What grading practices are followed?
• What species are in demand?
• What challenges do you face with drying, production, or sales?
• How do your customers view TMW?
• What tests do you perform on finished products?
• What safety systems or quality controls do you have in place?

The answers will help us map the current landscape and identify specific action areas. Most importantly, the survey will inform the work of the TMW Task Force as it develops standards and best practices.

HOW EVERY STAKEHOLDER CAN HELP
This is not just a technical conversation. It is a chance to reshape the future of wood in North America. And everyone in the industry can play a role.

If you are a manufacturer or producer, share your experience with feedstock, capacity, equipment, and product quality. Please help us understand what works and what needs improvement.

If you are a technology provider, tell us what your systems can do and what kind of support you offer. Your input is vital for setting process standards.

If you are a raw material supplier, let us know how you supply lumber, what moisture levels you can achieve, and how closely you work with modifiers. This helps connect upstream and downstream actors.

If you are a distributor or retailer, share what products are selling, what your customers ask about, and what is missing from the market.

If you are a builder or architect, tell us where you use TMW, what performance data you need, and what keeps you from specifying it more often.

If you are part of a policy, certification, or trade association, we invite you to help integrate TMW into your programs and bring it into wider recognition.

If you are a researcher or academic, we welcome your expertise in testing, performance, and innovation.

WHAT HAPPENS NEXT?
Once the survey responses are analyzed, the TMW Task Force will draft guidelines and recommendations. These will include:

• Grading criteria
• Moisture and quality benchmarks
• Recommended testing protocols
• Safety and emissions considerations
• Technical definitions and classifications

These materials will be shared with the industry to inform training, outreach, and public engagement. The final goal is a recognized, trusted standard supporting product integrity and market confidence.

ACT TODAY.
We invite you to be part of this effort in one or more of the following ways:

• Complete the TMW Stakeholder Survey
It only takes a few minutes but provides valuable insight for the entire industry.

• Join the NHLA TMW Task Force
We welcome your involvement if you’d like to contribute your voice and experience to standard development.

• Spread the Word
Encourage your network to learn about TMW, participate in the survey, and explore the benefits of this product class.

• Educate Yourself and Others
Visit www.nhla.com to access articles, updates, and learning resources.

TMW is not just a new product. It is a better way to use the resources we already have. It helps us strengthen domestic markets, reduce waste, improve quality, and meet the growing demand for natural, high-performance wood.

With the right collaboration, standards, and outreach, TMW can move from a niche solution to a mainstream material. But that can only happen if we work together.

Let’s build something better. Let’s create clarity, trust, and value for everyone involved in the TMW industry.

Be part of the movement. Help shape the future of Thermally Modified Wood in North America.

We want your input—make your voice heard!
Take the survey now at surveymonkey.com/r/2PC9ZVQ

By SAILESH ADHIKARI, Director of Research and Development
and DALLIN BROOKS, Executive Director of NHLA