Mataverde Decking Blog

Crushing it with Thermally Modified Western Hemlock Decking

Written by Chris Nolan | Tue, Apr 30, 2024 @ 09:04 AM

Western Hemlock is a strong and beautiful North American wood species. By itself, it is not very durable outdoors. That’s where thermal modification comes in. When Western Hemlock is thermally modified, the wood becomes exceptionally durable, stable, and resistant to insects and decay. It looks a lot like Western Red Cedar – maybe even better.

Thermawood Hem Fir makes an excellent decking material

Thermally modified Hemlock can be used for various applications, including exterior siding, decking, cladding, trim boards, and outdoor furniture. Thermally modified softwoods are prevalent in Europe, where thermal modification of wood has been extensively used for both residential and commercial projects. In Europe, they use mostly native pine, larch, and other local softwoods.

RELATED: Thermawood Hem Fir Decking

In North America, native Western Hemlock and Hem Fir wood species are widely available. Mataverde Thermawood uses a unique process that requires less heat and energy to produce. By thermally modifying the wood under pressure, in a vacuum kiln, energy is saved – and the thermally modified wood is stronger than the original wood.

In fact, it is so strong that it got our team wondering. How strong is it? “Can Rob drive his truck over it?” “Hey, the boss is out, let’s try it!” And off the merry pranksters went. Check out their shenanigans and informal test results here:

 

 

Technical Information About Thermawood Hemlock:

Hemlock is a popular wood species for construction and woodworking due to its workability and strength, and thermal modification further enhances its properties. Thermally modified Hemlock wood, often referred to as "heat-treated Hemlock," is a type of wood that has undergone a specialized thermal modification process to enhance its durability and stability, while also improving its aesthetic qualities. 

  1. Increased dimensional stability: Thermally modified Hemlock wood is less prone to swelling, warping, and shrinking when exposed to changes in moisture and humidity. This makes it a good choice for outdoor applications like decking, siding, and trim.
  2. Improved resistance to decay and insects: The heat treatment reduces the wood's moisture content and breaks down the sugars (hemicellulose), making it less attractive to fungi and insects. This enhanced resistance to decay and pests is valuable for exterior use.
  3. Enhanced color and appearance: The thermal modification process darkens the wood, giving it a more consistent, rich, and attractive appearance. This can eliminate the need for staining or painting, allowing the wood to age gracefully. It compares favorably to the lighter colors found in the upper grades of Western Red Cedar.
  4. Reduced maintenance: Because thermally modified Hemlock wood is more stable and resistant to decay and pests, it requires less maintenance over its lifespan, making it a cost-effective choice in the long run.
  5. Improved insulation properties: Thermally modified wood may have improved insulation properties due to its reduced moisture content and altered cell structure. This can be advantageous for certain applications, especially exterior wood siding, and trim.
  6. Can be fire retardant treated: Mataverde Thermawood FR meets all the requirements for WUI (Wildland Urban Interface) codes and IWUI (International Wildland Urban Interface) codes. IWUI codes are the most stringent codes worldwide and Mataverde FR passes them handily.

Not all thermal modification processes are created equal. If you're looking for a beautiful, decay-resistant, natural wood decking material, available in long lengths, consider Mataverde Thermawood Hemlock decking for your next project or design. 

RELATED: Thermally Modified Decking Project Picture Gallery

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