Wood is Good, Heat is Neat
An overview of what thermally modified wood is and is not.
What do lumberjacks, beavers and today’s high end designers all have in common? They love wood! And we do too! Wood surrounds us and is as commonplace as a silver diner in a flyover town. Wood floors, railings, decks, siding, framing lumber, furniture, cabinetry—wood is a staple in both interior and exterior design. But, when it comes to exteriors, you are forced to deal with nature, and she can be a mother.
Wood is good. Rot is not.
So let’s level-up wood, shall we? Heat is neat.
Did you know that wood can be thermally modified to remove moisture and stabilize the wood while simultaneously removing susceptibility to rot, decay, pests and those other pesky nuisances imparted by Father Time?
Wood modification is not brand new, but thermal modification in the domestic United States is a unicorn.
There are other ways to modify wood, like chemical modification, but that introduces chemicals to swell the wood cells and requires special species that are often shipped around the world before they end up here. We appreciate the well-traveled, but when we have perfectly good, sustainably managed wood here in the US, we will go ahead and save the extensive travel for a well-earned vacation.
This is not pressure treated, folks. That is a chemically laden process that does extend the life and durability of the wood, but not to the extent that thermal modification does. Pressure treated wood will, at the end of its life, leach chemicals into the soil. Thermally modified wood does not include any chemical treatments, it is more like a steam facial than a chemical peel. The wood is dried in an oxygen-starved environment and then moisture is reintroduced (strategically) to create the final product: a lightweight, durable wood with a 30+-year life expectancy. Many relationships don’t last that long, but your deck and exterior will with this long-performing wood in the mix. Thermal modification takes wood to the next level while still retaining the natural aesthetic at a good price point.
Let’s get technical.
Each wood cell has a hole in the middle called the lumen, which is like a little micro-cup filled with water. The water is either bound water, which is literally attached to the sides of the lumen to hydroxyl groups, or free water which is the liberated water which can leave or arrive whenever it wants, like your sister’s on again off again boyfriend. Because the bound water is trapped in the relationship, it is what expands or contracts and causes rotting issues in normal wood. During thermal modification, when things “heat up,” the hydroxyl bonds are broken, reducing the amount of water that can be bound, thus preventing the all too frequent break up or split. Free water can still sit in the lumen but it evaporates quickly or leaves when you need it to. (Hear that, boyfriend?)
Let’s get physical.
Looking good, wood. Thermally modified wood is very laterally stable, making it great for decking, cladding and other dimensional lumber. It has a 30+-year life expectancy. The technology works across a range of wood species including those that grow natively, like pine and ash, making it a more sustainable option because it can be both sourced and processed locally.
The Europeans have always led with design and grasped technology in building materials earlier than the US—this also holds true for their concern for the environment. The US has made some dramatic climatic missteps and could take a few cues from the cramped constituents over in the EU. Thermally modified wood has a massive share of the timber market in Europe and it only stands that it is time for the technology to be begrudgingly embraced by our obstinate selves in the US. Thermal modification can be performed on over 15 species of tree, even those sourced from a construction site. If you are trying to creatively tie a whole project together with native wood from a site, thermal modification is a compelling option.
Let’s get Real.
Marble looks are everywhere. Like annoyingly everywhere. But those hard glossy surfaces need a humble, softer side, and that is where wood comes in as the perfect complement to things like sintered stone or recycled glass, quartz or granite. Wood is like the good cop, the nice one, who warmly complements the more stoic, showy stone-faced lead. Thermally modified wood takes wood and makes it better. Its increased durability means less turnover, less replacement, less maintenance, and all domestic, which is great if LEED, WELL, Fitwel, or Biophilic Design are in your vocab. For a slightly higher cost, you get a more durable, stable, chemical free, circular material that embodies carbon.
Not to ceremoniously wave the green flag and jump up and down screaming about vegan meatballs, but it is important that we understand that wood captures carbon and keeps it out of the atmosphere. Taking captured carbon and turning it into a building material that lasts for over 30 years is how we need to be designing today if we want to have a deck to host a BBQ on tomorrow. Or a roof deck to have a retirement party on in 2052.
Let’s get out of here.
Thermally modified wood is going to change the way wood is used in design.
Time to get on board.