What is Thermowood and Why Is It Used For?

Thermowood is a type of wood that has been treated to improve the properties of the wood through a method called thermal modification. Thermal Modification is a process in which the chemical properties of wood are modified with heat and steam. During this process, the minimum modification temperature is 160°C. The consequent changes in the wood structure are permanent.  

Thermal treatment reduces the water content of wood while also increasing its resistance to rot, decay and insect damage. It also reduces shrinkage and swelling, increasing the dimensional stability of the wood. Therefore, thermally treated wood is more durable, environmentally friendly and long-lasting.

Thermowood is generally used in outdoor applications, especially in exterior cladding, terraces and outdoor furniture. It can also be used in interior applications, for example in interior decoration, furniture making or floor coverings.

Thermowood Classes

In the standard Thermowood treatment classification there are two classes of heat treatment, Thermo-S and Thermo-D


It involves heating wood (typically 160°C to 220°C) in a low-oxygen environment, softening it by breaking down hemicellulose and lignin. This improves dimensional stability, reduces moisture content, and enhances resistance to decay and insects. 


It heats wood to higher temperatures (180°C to 240°C) while compressing it, increasing density and reducing porosity. This strengthens the wood, improves dimensional stability, and enhances resistance to moisture

Thermal Modification phases

🔸Phase 1: High temperature drying: Using heat, the oven temperature is raised to 100⁰C quickly. Then, the temperature is constantly raised to 130⁰C, during this time the wood is dried and the moisture is reduced to zero.

🔸Phase 2: Thermal modification and cooling: The temperature in the wood is increased to 180⁰C (Thermo S) and 212⁰C (Thermo D) with water vapor. When the target temperature is reached, this heating process is applied for 2-3 hours.

🔸Phase 3: Moisture conditioning: In this last part, the temperature of the wood is lowered to 80⁰C – 90⁰C by the use of the water spray and it is continued until the humidity of the wood reaches 4–6%.

Advantages of Thermowood

In the field of sustainable construction and design, the search for the use of environmentally friendly materials is gaining momentum. Among these materials, thermowood stands out because it combines innovation with environmental responsibility. Offering many advantages, thermowood stands out as a preferred option by architects, designers and homeowners. Let's take a look at the advantages that make Thermowood an attractive option for a variety of projects.

1. Natural and Chemical-Free

One of the most attractive aspects of Thermowood is its 100% natural composition. Thermowood, which is free from resin and other harmful chemicals, is produced without the use of any chemicals. This not only ensures a safer environment during production, but also contributes to healthier living spaces.

2. Ecological and Environmentally Friendly

In today's world where environmental sustainability is at the forefront, thermowood stands out as an ecological solution. Thermowood, which is harmless to humans and other living species, internalizes environmental friendliness. Additionally, being recyclable, Thermowood minimizes waste and promotes a circular economy. Its durability, longevity and durability also increase its environmental properties, reduces the need for frequent replacement and saves resources.

3. Superior Durability

The durability of Thermowood is unmatched, making it a reliable choice for a variety of applications. Regardless of weather conditions, Thermowood maintains its integrity and resists rot and insect damage. This inherent durability means long-lasting structures and products, reducing maintenance efforts and costs over time.

4. Increased Stability

Stability is an important factor for construction and design, and Thermowood exhibits superior performance in this regard. Thanks to the heat treatment process, thermowood undergoes structural changes and increases its stability. This reduces the risk of warping, warping or cracking, preserving the original form and functionality of your projects for years to come.

5. Homogeneous Color

Beyond its functional advantages, Thermowood also offers aesthetic advantages. The heat treatment process makes the wood have a more homogeneous color and increases its visual appeal. Achieving this color harmony allows it to be seamlessly integrated into various design schemes, providing a consistent and harmonious look.

Where is Thermowood Used?

Exterior Decking

Thermowood is frequently preferred in exterior cladding because, thanks to thermal treatment, problems such as wood rotting and cracking are reduced and its durability increases.

Exterior Decking

Thermowood decking is popular due to its improved durability and resistance to moisture and decay compared to untreated wood decking.

Outdoor Pool Sides

Thermowood is frequently preferred around outdoor pools and sun loungers because it is water resistant.

Outdoor Landscape Applications

It can also be used in outdoor landscaping applications such as garden paths, terraces, sunshades and pergolas.

Interior Design

Thermally treated wood can also be preferred for interiors. It can be used for ceilings, wall panels or furniture, especially if an aesthetic appearance is desired.

Saunas and Baths

Thermowood's resistance to humidity and temperature changes allows it to be used in high humidity environments such as saunas and Turkish baths.

Last Words

Thermowood offers an important solution for those seeking sustainability in the world of construction and design. This special type of wood, obtained through thermal processing, stands out as an environmentally friendly option with its natural and chemical-free structure. It is preferred by architects, designers and homeowners with its ecological, durable and aesthetic features. Leading manufacturers such as Novawood show that Thermowood is a material that attracts attention with its various usage areas and the advantages it offers. This makes it an attractive option for those looking for innovative and environmentally friendly solutions in building materials and decoration projects. With these features, Thermowood not only meets today's needs but also supports the vision of leaving a more sustainable world to future generations.