The same species, the same log — and completely different behavior outdoors. The difference isn't a treatment or a coating: the wood itself changes. Below is what changes, what it costs you, and when ordinary timber is honestly the better buy.
Thermal modification heats timber to 180–215 °C with no chemicals. Sugars and hemicelluloses break down, leaving rot and wood-boring beetles nothing to feed on, and equilibrium moisture content falls from 12–15% to 4–6%, so the board barely takes up water and holds its geometry. The price is a 26–45% loss in bending strength and more frequent surface micro-checking. Ordinary timber is cheaper and stronger, but outdoors it lasts years rather than decades.
A pine board costs a fraction of thermo-karagach. If the budget is tight, that settles it.
Modification cuts bending strength by 26–45% and splitting resistance by 30–40%. For load-bearing members ordinary timber is the right choice — which is why our own frame is steel, not thermowood.
Any yard, any length, tomorrow. Thermowood is made in batches to a kiln schedule.
Damage a board in three years and you buy an identical one within the hour. With thermowood that's an order.
The sugars and hemicelluloses that wood-destroying fungus lives on are broken down. The resistance can't wash off, because it isn't a treatment — it is changed timber.
Equilibrium moisture content of 4–6% against 12–15%. That's where the dimensional stability comes from: less cupping and twisting season to season.
Not a coating: the tone runs through the full thickness. A scratch doesn't expose white wood, and sanding returns it to day one.
No Rot — 10 years on karagach and ash, 5 on pine and birch. Nobody gives that on ordinary timber, because it can't be given.
| Property | Ordinary timber | Thermowood |
|---|---|---|
| Equilibrium moisture content | 12–15% | 4–6% |
| Food for wood-destroying fungus | sugars intact | broken down by heat |
| Bending strength | baseline | 26–45% lower |
| Color | on the surface | through the thickness |
| Surface micro-cracks | present | often more of them |
| Fading in sun | yes | yes — oil restores the color |
| Guarantee against rot | nobody offers one | 10 years karagach and ash |
The question isn't which is better but how many years this structure has to live and who will look after it. For a fence you're happy to redo in five years, ordinary timber is the honest answer and we'll say so. For a terrace, a facade or a canopy soffit, where replacement means taking half the backyard apart, the price difference is paid once and the difference in behavior works every season.
If it is a load-bearing member, buy ordinary timber or steel — thermowood isn't meant for it. If the budget won't stretch and you're content to replace in a few years, buy pine and don't overpay. And if you need it tomorrow: we produce in batches, and ordinary board is in every yard today.
Thermowood or larch
Thermowood or composite
Karagach or ash
Thermal modification heats timber to 180–215 °C with no chemicals. Sugars and hemicelluloses break down, leaving rot and wood-boring beetles nothing to feed on, and equilibrium moisture content falls from 12–15% to 4–6%, so the board barely takes up water and holds its geometry. The price is a 26–45% loss in bending strength and more frequent surface micro-checking. Ordinary timber is cheaper and stronger, but outdoors it lasts years rather than decades.
The question isn't which is better but how many years this structure has to live and who will look after it. For a fence you're happy to redo in five years, ordinary timber is the honest answer and we'll say so. For a terrace, a facade or a canopy soffit, where replacement means taking half the backyard apart, the price difference is paid once and the difference in behavior works every season.
If it is a load-bearing member, buy ordinary timber or steel — thermowood isn't meant for it. If the budget won't stretch and you're content to replace in a few years, buy pine and don't overpay. And if you need it tomorrow: we produce in batches, and ordinary board is in every yard today.
