Thermally Modified Wood Decking

Premium thermally modified wood decking boards for residential and commercial projects

Janka

Varies by species

Density

25-35 lbs/ft³

Fire Rating

Class B-C

Durability

20+ years

Origin

North America

Color

Rich brown

Overview

Thermally modified wood decking is produced by heating domestic softwood or hardwood species to temperatures of 400-500°F in oxygen-free kilns, permanently altering the wood's cell structure. This chemical-free process dramatically improves decay resistance, dimensional stability, and insect resistance while creating a rich, deep brown color throughout the board. Thermally modified decking offers a sustainable, high-performance alternative to both pressure treated lumber and imported exotic hardwoods — delivering 20+ year durability from North American species like ash, pine, and poplar.

Thermally Modified Wood Decking wood grain

Learn more about this wood species on our Thermally Modified Wood wood guide.

Benefits of Thermally Modified Wood Decking

100% chemical-free process — no preservatives or toxins

Class 1 durability rating (comparable to tropical hardwoods)

Dramatically improved dimensional stability

Natural resistance to rot, decay, and insects

Rich, consistent brown color throughout

20+ year lifespan for outdoor applications

Sustainable — uses domestic North American species

Lightweight and easy to work with

Sizes Available

1x6 Thermally Modified Decking

5/4x6 Thermally Modified Decking

2x6 Thermally Modified Decking

1x4 Thermally Modified Decking

Custom profiles available

Standard lengths 8'-16'

Custom sizes and lengths available. Request a custom quote.

Installation Tips

Pre-drill near board ends to prevent splitting — thermal modification makes wood more brittle.

Use stainless steel or coated deck screws.

Allow 1/8" to 3/16" gap between boards for expansion.

Acclimate boards on-site for 3-5 days.

Use standard woodworking tools — no carbide tips required.

Hidden clip systems work well with profiled boards.

Maintenance

Apply a UV-protective oil annually to maintain the rich brown color. Without UV protection, thermally modified wood will weather to silver-gray (the structural integrity is unaffected). Clean with mild soap and water. Thermally modified wood holds oil finishes well and is easy to refinish. Avoid high-pressure washing which can damage the modified surface.