Material Focus

Thermally Modified Wood

A Different Approach to Durability

With sustainability at our core, we think carefully about how wood performs over time, especially when it is exposed to weather and seasonal change. Thermally modified wood matters to us because it improves durability without compromising the integrity of the material or the environment it comes from.

Thermal modification uses high heat in a controlled, oxygen-free setting to permanently change the wood’s cellular structure. No chemicals are added. The result is a wood product that behaves differently than untreated lumber, particularly outdoors.

By limiting the wood’s ability to absorb moisture, thermal modification creates a material that remains more stable over time. For us, this is about stewardship. When we reclaim a tree, our responsibility does not end at milling. We want that material to last.

Research-Backed Performance

We rely on more than theory when evaluating new processes. Research conducted by the Natural Resources Research Institute (NRRI) at the University of Minnesota has played an important role in validating thermal modification for North American wood species.

Their work has helped confirm durability improvements and expand the use of domestic hardwoods in exterior applications, particularly in climates with significant moisture and temperature variation. This research supports what we see in practice and reinforces our confidence in thermal modification as a responsible path forward.

Where Thermally Modified Wood Works Best

Thermally modified wood performs best in applications where weather resistance, stability, and longevity matter most. It is commonly used for exterior siding, decking, soffits and trim, fencing, and architectural accents.

The process also deepens and enriches the wood’s color, creating a refined aesthetic that works in both modern and traditional designs. Left unfinished, it weathers naturally. When sealed, it holds finishes more evenly over time.

We are actively exploring how thermally modified reclaimed hardwoods can expand design possibilities while preserving the character and story of urban wood. If you have a project you think might be a good fit, lets talk.