The thermal modification process involves the heating of the wood material to a temperature of over 400o while at the same time protecting it with steam.  The process is 100% natural – only heat and steam are used in the process, no chemicals are added. During the high heat process moisture is almost completely removed from the fiber which cooks the natural tannins and sugars in the cells of the wood, permanently changing their structure. Steam is then added back to the fiber to retain its flexibility and workability.

You don’t have to cut down a 400 year-old forest to get a totally natural product that has both a high resistance to decay and dimensional stability and a natural beauty.


As a result of the thermal modification process several changes occur within the wood.

  • The color darkens to a deep, rich brown tone similar to old growth Cedar and Redwood or tropical wood species. This color change is throughout the fiber, not just on the surface as with stains and chemical treatments.

  • The density of the wood is increased, lowering its heat conductivity.

  • The wood cell walls are modified to the point of reducing its water absorption ability, making Excalibur Wood more dimensionally stable. Limiting cupping, expansion and contraction. This also makes Excalibur Wood more resistant to rot and mold.

  • Thermally modified wood no longer contains sufficient sugars and nutrients to support insect or fungal attack, making Excalibur Wood very resistant to infestation.


It is important to remember that Excalibur Wood is a natural wood product and grain, original color variances and other characteristics of wood are still present.  Excalibur Wood will experience graying when exposed to UV rays like all other wood products, but UV inhibitors will slow this process.

As with all high quality woods, pre-drilling prior to installation is recommended.

Oil based stains and paints are suggested as the thermally modified wood does not absorb water very well.  Water based glues and paints will work but absorption will take longer.

Initially there is a slight smell of thermally modified wood, similar to charcoal, which some people find unusual.  This aroma will fade away in 1-2 months and finished or “smooth” lumber rarely has any smell.