Durable, flexible, and environmentally friendly wood sourced, modified, and distributed in the USA.

What Makes KLAASWOOD Different?

KLAASWOOD uses an innovative, 2nd generation hydrolysis technology that is changing the landscape of thermally modified wood.

Sourced And Modified In The USA. 

KLAASWOOD wood is the only modified wood that is both sourced and modified in North America. This makes KLAASWOOD an obvious choice when you look to reduce logistic costs and risks while minimizing the ecological footprint. Locally grown and modified wood by North American workers guarantees you a readily available premium product.

Superior Durability & Performance.

KLAASWOOD offers superior durability without the use of chemicals. The treatment process reduces the wood’s ability to absorb or release moisture, resulting in improved stability and reduced warping, shrinking, or swelling, and is also more resistant to decay, rot, and fungal growth. The wood meets the requirements of Durability Class One performance and comes with a certified 20 year warranty.

Affordability Without Compromise.

We take pride in being cost-competitive without sacrificing excellence. KLAASWOOD utililzes widely available wood sources to provide strong and durable wood that surpasses the qualities of premium wood sorts, and our 2nd Generation thermal modification process uses less energy and increased efficiency to lower the cost and make the product more affordable.  

Where Beauty Meets Sustainability.

The thermal modification process is carried out without the use of chemicals, making it a sustainable alternative compared to some other wood treatments using biocides. It is also fully recyclable and has an optimized CO2 footprint compared to other products.

How Do We Achieve Durability Class 1?

Through an extensive review of existing research, our analysis has revealed a robust correlation between Equilibrium Moisture Content (EMC) and Durability Performance, a standard measure in our industry and practical for quality assessment during manufacturing. Lower EMC levels in modified wood are linked to superior durability performance. 

Based on rigorous laboratory testing involving 900 specimens from five different species, we conducted data analysis and presented our findings at the 11th European Workshop on Thermally Modified Timber in the spring of 2023. Our study demonstrates with high statistical significance that an EMC level at or below 6 results in the highest durability performance, reaching Durability Class 1.

We are proud to confirm that all KLAASWOOD products meet the EMC standard of being at or below EMC = 6, as assessed using our established sampling and preparation procedure.

With a reduced lead time, a lower CO2 footprint, and high-performing, beautiful wood that is readily available, we are ushering in a new era of wood technology that not only improves the way the wood is used in society in general but also makes a positive impact by reducing the use of chemicals and preserving natural resources.

Welcome to a new era of wood modification technology, where innovation meets sustainability and beauty and durability coexist.


Whether you prefer modern or traditional architectural styles, KLAASWOOD’s thermally modified siding complements them all, making it a versatile and sustainable choice for those seeking both beauty and durability.


KLAASWOOD’s thermally modified wood decking has been created for those seeking a harmonious blend of aesthetics and resilience in their outdoor spaces. Whether you're designing a contemporary outdoor oasis or a rustic retreat, thermally modified wood decking offers versatility and sustainability.


With its minimal maintenance requirements and exceptional longevity, KLAASWOOD’s thermally modified wood trim ensures your project will maintain its visual appeal and resilience for years to come.


KLAASWOOD is taking wood to the next level in the construction of our modern society. The use of thermally modified wood not only enhances the sustainability and longevity of your architectural projects, but also adds a touch of timeless beauty to the built environment.

Next in Innovation

We believe in the unity of technology and nature, creating a balance that allows for both beauty and durability in wood.

Next in Wood

We are committed to sustainability and reducing our environmental footprint, while providing high-quality, aesthetically pleasing wood that is safe for all.

Next in Modification

We are dedicated to creating a new era of wood technology where innovation meets sustainability, and where wood is easily accessible, safe and of high-quality.