Thermally Modified Lumber


Many people in the United States are unfamiliar with thermally modified wood.  Although the process has been around in some form or another for centuries it hasn’t been until recently that the product has started to gain momentum in this country.

Thermally modified wood can trace its beginnings back to the Vikings who discovered the advantages of burning wood in order to get the most out of a scarce resource.  The process preserved wood and helped make their homes more impervious to the elements.  Modern technology has brought the process of treating lumber with heat to a whole new level.

Wood modifiers currently fall into about 3 categories; heat modification only that changes the internal structure of the wood, heat and chemical modification combined that achieves results superior to heat alone and external heat modification only.

A traditional thermally modified wood process heats the material in the absence of oxygen to alter the internal composition to increase durability.  This process removes organic compounds from the wood and prevents the absorption of water which in turn eliminates food sources for insects and fungi.  An even older method of thermally modifying wood is to burn or char the outside of the wood, this process is referred to as Shou Sugi Ban or Yakisugi.  This process carbonizes the exterior of the wood and makes it resistant to water, rot and insects.  The process can be seen in many design aspects of modern builds due to the unique texture and appearance it imparts to the wood.

A third process uses both heat and chemicals to modify the wood.  The wood is soaked with a furfuryl alcohol then heat treated to produce a material that has all the characteristics of traditional thermally modified wood but also imparts a level of hardness to rival tropical hardwoods.  In an age when sensitivity to sustainable timber farming is becoming a larger issue, this system could provide viable alternatives for the future.

In the end, our ability to change wood with heat is as old as our search for shelter.  Whether your goal is a unique look or feel, durability in the face of mother nature or the careful stewardship of natural resources then thermally modified wood could be the right choice for you.