Thermowood vs. Natural Wood: What's the Real Difference, and Which One Wins Where?
Thermowood is the same wood, just heat-treated; here's what that heat actually changes, and where raw natural wood still wins.
Thermowood Species and Color Types: Which Fits Where
The final color of thermowood depends on the original wood species and the heat-treatment temperature; from light cream to burnt brown, each shade suits a different use.
Many people ordering thermowood assume it all comes in one color and one species. In reality, the final color depends on two things: the original wood species and the temperature applied during the heat-treatment process. These two factors are why one project's thermowood turns out light cream while another's ends up a dark brown close to burnt.
How the Source Species Matters
Thermowood is usually made from pine, fir, or poplar; each has its own natural color before treatment, and that base color affects the final result too. Pine and fir, being lighter and more widely available, are the most common choice for decking and facades. We cover how these treated species differ from untreated natural wood in this article.
Temperature: The Main Driver of Color Change
In the thermo process, wood is heated to a high temperature — typically between 160 and roughly 210 degrees Celsius. The higher the temperature, the darker the color and the lower the moisture penetration, but the wood structure also becomes slightly more brittle. That's why, for a surface under heavy mechanical load, a workshop needs to balance color depth against mechanical strength rather than just picking the preferred shade.
- Light color (lower treatment temperature): higher mechanical strength, suited to decking and flooring
- Medium-dark color: a good balance of look and durability, suited to facades and wall cladding
- Dark brown near-burnt color: a more luxurious look, better suited to low-contact surfaces like interior walls
- Pine and fir: the most common and economical choice for large projects
A darker thermowood color doesn't always mean higher quality — sometimes it just means a higher treatment temperature.
Choosing the Right Color for Your Project
For an outdoor deck that takes foot traffic and direct sunlight, a lighter color with higher mechanical strength is usually the more sensible choice. For an interior sauna wall or a decorative facade that sees less mechanical contact, a darker shade can give a more luxurious look without much concern for durability.
Summary
Before ordering, always ask the workshop which species and what treatment temperature produced the color sample — these two questions are enough to tell whether the chosen color is mechanically right for your installation site, or just good-looking.
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Thermowood in Saunas and Steam Rooms: Why This Wood Holds Up
Saunas and steam rooms are the harshest environment wood ever faces: intense heat and constant moisture. Here's how thermowood copes with it, and where you still need to be careful.