exterior decking

Potential Woods for Use in Outdoor Applications

When you’re constructing a deck or building Adirondack chairs for your backyard, you want to make sure you choose a wood that can stand up to the elements.  While many people go straight to treated yellow pine for outdoor projects (it is the cheapest and most common option), there are plenty of wood species that hold up at least as well even when left untreated.  Here are a few woods to consider for your next outdoor project.


This tropical hardwood from Central and South America makes an excellent choice for outdoor projects, including decking.  Ipe is very hard and dense and resists warping, cracking, and decay extremely well.  Its oil and extractive content makes it highly resistant to insects and fungi, and untreated ipe can last up to 40 years outdoors.  Its density makes it fairly impervious to denting and foot traffic, but also hard to cut. 


Long a popular choice for boat building, teak is another good candidate for outdoor applications.  Teak is prized for its beauty as well as its durability outdoors, and you can expect to pay a premium for it.  Teak’s high stability means it won’t shrink or expand much with changes in humidity, and its natural oils and extractives repel water and deter insects.  Unlike ipe, teak works easily.  One caveat: most teak on the market is not sustainably sourced, so if you’re concerned about the environmental impact of your wood choices, look for certified sustainable forested teak. 

African Mahogany

Less expensive than teak but more expensive than ipe, African mahogany is another top of the line choice for outdoor applications.  African mahogany is a durable hardwood that resists decay, infestation, and warping and is easy to work.  Left untreated, its durability will endure a very long time, but its beautiful reddish color will fade to gray.

VG Fir

Vertical Grain (VG) Fir has been a traditional choice for porches for over a century due to its wide availability and durability, both of which still make it a good choice today. VG fir is quite dimensionally stable, so it expands and contracts evenly and is unlikely to warp.  Naturally resistant to decay and insects, VG fir can last 10-15 years outdoors untreated, and is an affordable choice.

Western Red Cedar

Western Red Cedar is another widely available, reasonably affordable choice for outdoor use.  It’s dimensionally stable, typically straight-grained, and resists warping, decay, and insects (including termites).  Untreated, Western Red Cedar will last about 20 years outdoors.  As cedar is a softwood, you can expect to see some damage from foot traffic if using it as decking or flooring.  Beware of splitting when driving fasteners, and expect tannins to appear as stains around them.

Is Thermally Modified Hardwood Lumber Here To Stay?

Thermally modified hardwood may represent an up-and-coming contender to compete with treated wood and composite products. Thermally treated wood boasts advantages over both.

The question remains whether this product will be adopted by consumers. The process is not well understood by those outside of the wood industry. There is even confusion and misconceptions among woodworkers. Lack of understanding is a major barrier to entry into the markets. The success of this product will be heavily dependent on overcoming that barrier and helping users interested in thermally modified hardwood.

The American Hardwood Export Council recognizes thermal modification as a developing market with great potential for American hardwood producers. There are various species that can be successfully treated such as – ash, soft maple, tulip poplar, red oak, yellow birch and hickory. Appearance of

Thermally Modified Hardwood Piques Consumer Interest

The darker wood tones created by the treatment process for thermally modified wood resemble some exotic hardwoods. Designers and consumers alike have been drawn to being able to obtain this dark mocha color without having to apply a wood stain. In addition, having a wood grain choice other
than spruce, pine, and fir, is a refreshing change.

Exterior Performance of Thermally Modified Wood Holds Up

Thermally modified hardwood has similar physical properties to traditional wood choices. Thermally modified wood strength is on par with the same species that has not been thermally modified. You can cut, drill, nail and screw thermally modified wood the same as traditional wood. There are also no special fasteners required with thermally modified wood, but you can use a hidden deck fastener system if you wish.
The story of thermally modified hardwood is a good one – now we just need to do a good job of telling it.
Learn More About What Thermally Modified Wood Can Be Used For.

What is Thermally Modified Wood?

Wood treated with thermal modification has been through a natural, non-toxic process that basically cooks the wood, changing the make-up of the wood. Wood is heated in 400+ degree heat in an oxygen-free environment.

How is Thermally Modified Wood Physically Different?

Thermal modification uses heat to remove organic compounds from the wood cells, so it will not absorb water, expand, contract, or provide nourishment for insects or fungi. The high heat produces a naturally durable wood that is permanently resistant to water, insects, and decay. Because the wood is not absorbing chemicals to be treated, but rather removing moisture, the wood is lightweight.

Thermally modified lumber is also more dimensionally stable because it is less susceptible to cupping and warping. The wood has increased heat resistance and weather resistance as well. When properly maintained, it will not chip, rot, or warp over the years. Many products offered in this category are rated for 20 or 25 years of exterior use.

How Does Thermally Modified Wood Look Different?

The high gradual heat process creates permanent reactions and gives the wood a rich, deep brown appearance. The darkened color brings an unexpected tropical look.


The chocolate color can be maintained in exterior applications by finishing the wood with a UV-inhibitor sealant on all sides and ends of the wood. If not finished, the wood will naturally weather to a shade of gray because of exposure to the sun’s ultraviolet rays.

What Can Thermally Modified Wood Be Used For?

Since thermally modified wood does not absorb or hold moisture as it would prior to treatment, species that typically do not perform well in outdoor or wet environments can now be used in a variety of applications, such as decking, siding, or flooring. It can also be used in environments that are less stable in moisture content, such as basements (with proper sub-flooring).

The Benefits of Thermally Modified Lumber

This thermally modified wood is eco-friendly since harsh chemicals are never used in the development of this product. Unlike pressure-treated lumber, it will not corrode metals. As previously mentioned, it is also dimensionally stable with incredible durability.

A New Non-Toxic Product for Outdoor and Indoor Use

Thermally modified lumber is a green alternative to tropical hardwoods and pressure treated lumber for exterior uses and is an beautiful product to use in other applications where stability and durability are key variables.

Interested in learning more about thermally modified lumber? Visit our distributors list to find a distributor in your area.

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