Anyone specifying materials today for façades, exterior joinery, or outdoor spaces looks beyond appearance and cost. Circularity, maintenance, lifespan, and origin carry increasingly more weight. At the same time, demand is growing for alternatives to tropical hardwood with the same durability and a smaller ecological impact.

The Belgian-produced ThermoWood^® from LDCwood^® fits this search. Through thermal modification, a wood product is created that is more resistant to moisture, more dimensionally stable, and suitable for a wide range of applications.

An alternative to tropical hardwood

ThermoWood^® starts from fast-growing wood species such as pine, spruce, ayous, frake, ash, and poplar, from sustainably managed forests with an FSC^®, PEFC, or OLB certificate. This combination of durability and Belgian production makes it a fully-fledged alternative to tropical hardwood in façades, decking boards, and exterior joinery.

What thermal modification does

In a controlled process, we expose the wood to high temperatures and steam, without chemical additives. As a result, the wood absorbs less moisture, is more resistant to fungi, and responds less to fluctuations in temperature and humidity. This results in greater dimensional stability and stable joints.

The downside: the wood loses part of its density and structural strength. ThermoWood^® is therefore not suitable for load-bearing applications, but it is ideal for façade cladding, terraces, sun-shading slats, exterior joinery, and furniture.

The right wood species for the right application

The choice of wood species remains decisive. "After treatment, ayous achieves the highest durability class, class 1, and is particularly suitable for façades thanks to its light weight and uniform appearance. It is not suitable for terraces, because ayous decreases in density. There, sturdier species such as frake perform better," explains Elsie Demulder of LDCwood®. That is why we select the wood already in the sawmill, before modification.

A protected quality label

ThermoWood^® is not a generic term, but a protected label of the International ThermoWood Association (ITWA). Independent bodies inspect our production several times a year for process parameters, moisture content, density, and traceability. We track the origin of the wood through FSC^® and PEFC.

Specifying correctly prevents surprises

Projects mainly run into trouble when aesthetics, fire-reaction requirements, and technical performance are not aligned. A façade profile can be beautiful, but not always combinable with the required fire class. Early advice on profiles, wood species, and application conditions prevents this. For this, you can turn to the Lemahieu Academy, the knowledge platform of Lemahieu Group, of which LDCwood is part.

Maintenance

Under the influence of UV radiation, ThermoWood^® gradually weathers to an even silver-grey patina. This has no effect on performance. If you want to retain the original colour, you opt for a coating. In that case, maintenance shifts to that finishing layer.

Not sure which wood species best suits your project? View our range of ThermoWood^® or contact our team for tailored advice.

This article previously appeared on Architectura.be: More than an aesthetic choice: how Belgian ThermoWood^® supports sustainable architecture.