Phillips Lumber & Millwork

Phillips Lumber & Millwork

Thermally Modified Lumber

What is Thermally Modified? An up-and-coming contender to compete with treated wood and composite products. Thermally treated wood boasts advantages over both.

Its the process of cooking wood to 410 degrees Fahrenheit down to 0% moisture content to stabilize it and make it rot resistant. Any species of wood can be modified and make it perfect for outdoor use. We stock poplar, pine, and ash in various thicknesses. Its perfect for high end fencing, exterior mouldings, porch flooring or decking, water front areas and docks because there are no chemicals involved in this process, ONLY HEAT!


Thermally modified wood is a relatively recent innovation, developed in the 1990s as an alternative to traditional methods of treating wood with chemicals or preservatives. The process involves heating wood to a high temperature in the absence of oxygen, which causes changes to the wood’s physical and chemical properties.

The idea of thermally modifying wood can be traced back to the ancient Japanese technique of “yakisugi,” which involved charring the surface of wood to make it more resistant to fire and decay. However, it wasn’t until the 1990s that the process was refined and commercialized in Europe and North America.

The first commercial plant for thermally modifying wood was established in Finland in the middle 90s, and since then the technology has spread to other countries, including Canada, the United States, and Germany. The process has also been applied to a wide range of wood species, including pine, spruce, fir, oak, and ash. It also has a distinctive appearance, with a darker, richer color and enhanced grain patterns.

Whether a homeowner or contractor, Phillips Lumber is ready to discuss with you the options of using thermally modified wood for your project. We have happily served major locations such as Louisville, Kentucky; Indianapolis, Indiana; Cincinnati, Ohio; Chicago, Illinois.


Thermally Modified Vs Treated Material

Which is the better Option?

Thermally modified decking provides many advantages over treated decking. When compared and carefully examined, it is hard to deny the superiority of thermally modified decking. 

Increased Durability: Thermally modified decking undergoes a heat treatment process which removes moisture and volatile organic compounds from the wood, making it more resistant to decay, insect damage, and rot. This process also stabilizes the wood, reducing shrinkage and swelling over time. In comparison, treated wood is treated with chemical preservatives that may eventually leach out and lose effectiveness over time.

Better Aesthetics: Thermally modified decking has a beautiful and unique appearance due to the caramelization of sugars in the wood fibers during the heating process. This results in a natural, rich color that doesn’t fade easily. Treated wood, on the other hand, may have a greenish tint due to the chemicals used in its treatment.                        

Improved Eco-friendliness: Thermally modified decking is a more environmentally friendly option compared to treated wood. The heat treatment process uses only heat and steam, so there are no harmful chemicals released into the environment. Treated wood, on the other hand, requires the use of potentially hazardous chemicals, such as arsenic and chromium, to prevent decay and insect damage. 

Better Dimensional Stability: Thermally modified decking has better dimensional stability compared to treated wood, meaning it’s less likely to warp or split over time. This is due to the removal of moisture during the heat treatment process, which reduces the wood’s susceptibility to changes in moisture content.

There are various products that can be made from thermally modified wood material.

Decking: Thermally modified wood is an excellent choice for decking applications. Its increased resistance to rot, decay, and insect damage makes it ideal for outdoor environments. Whether you’re designing a residential deck, a commercial boardwalk, or a patio area, thermally modified wood decking provides a beautiful and durable solution that requires minimal maintenance.

Siding: The rich color and dimensional stability of thermally modified wood make it a great option for exterior siding. It offers a natural, warm appearance and can be used to create stunning facades for homes, cabins, and commercial buildings. With its enhanced resistance to moisture, thermally modified wood siding provides long-lasting protection and visual appeal.

Exterior Structures: Thermally modified wood can be used to create a wide range of exterior structures. From pergolas and gazebos to fences and shutters, this material provides an attractive and durable solution. Its resistance to moisture, insects, and decay ensures that these structures will withstand the test of time while adding beauty to outdoor spaces.

Architectural Elements: Thermally modified wood material can be shaped and crafted into various architectural elements, such as beams, columns, and trims. These elements add character and sophistication to both residential and commercial buildings. The natural appeal and durability of thermally modified wood make it a versatile choice for enhancing architectural designs.

At Phillips Lumber and Millwork, we specialize in creating high-quality products from thermally modified wood material. Our skilled craftsmen utilize this innovative material to craft decking, siding, and other custom products to suit your specific needs and style preferences.

Experience the beauty, durability, and environmental benefits of thermally modified wood. Contact us today to learn more about this remarkable material. We look forward to helping you create stunning and long-lasting products using thermally modified wood.