Q&A

Thermodecking company is always happy to answer questions from our customers. We analyse your feedback. In this section we have collected the most frequently asked questions and tried to answer them in detail.

About the company and terms of cooperation

Are you a manufacturer?

Yes, we are. Thermodecking is a production company that covers the entire wood production cycle and has the advantage of its own manufacturing and infrastructure facilities, a full complement of hands-on professionals and many years of experience.

Where and how can I place an order?

You can place an order through various methods—visit our office, contact us by phone +7 929 572 05 10, send an email to pavel@termod.ru or reach out via messengers WhatsApp, Botim, Imo, Telegram.

Do you deliver to the regions?

We arrange delivery using third-party transport companies that can deliver your order anywhere in Russia and the world. The costs are calculated according to the tariffs of the transport company and paid by the customer. The customer is free to choose the delivery company independently having previously agreed the place of collection with our manager.

What guarantees do you offer?

We guarantee a significant reduction in decay compared to non-heat-treated timber, with no decay for up to 25 years, provided the user complies with installation and operating conditions. We also guarantee the geometric stability of the material for 10 years (under the current specification) from the date of dispatch to the customer, provided that the customer complies with the storage and installation conditions and that the installation is carried out under the supervision of Thermodecking. The structural integrity guarantee is 30 years. This means that the shape and dimensions of the product will remain unchanged for the duration of the warranty, provided that all necessary transport, storage, installation, operation, and maintenance measures recommended by the manufacturer are followed.

About the material

Where can I see your products?

You can see our products in our Moscow office at Sormovsky proezd 7A bldg 2 or at our production facility in Lukhovitsy, Moscow Region, 10A Yuzhnaya Street. We can also send you samples or you can view them via a video link using Botim, WhatsApp, Telegramm and other services.

How do I get your samples?

You can receive samples in the way that is most convenient for you: directly at our office or, if you are out of town, by courier or transport.

What is the board coated with?

Initially, the heat-treated board is not coated. To prevent burnout, the application of tinted oil is recommended. You can either opt for us to coat the board at our production site, or you can choose to do it yourself.

What types of wood do you use?

We use industrially harvested wood for heat treatment, including ash, birch, pine, lime, alder, maple, and aspen.

Do you sell thermo larch?

No, we don’t sell thermo larch. Untreated larch itself is used for decking and facades. This wood species is resistant to decay, and its hardness is comparable to that of ash and oak. Thermowood surpasses larch only in geometric stability. Larch is heavily impregnated with resins; after thermal treatment, the resins dissipate, leaving the annual rings stratified. This process results in an inhomogeneous surface on the product.

Do you sell thermo oak?

No, we don’t sell thermo oak. Oak loses its valuable properties and becomes brittle and friable during the heat treatment process. A suitable alternative is thermo ash, which is comparable in quality to oak.

How much does the durability of thermowood increase?

After thermal modification, the hardness and wear resistance of the wood increases by 20-25%.

What is the thickness of the heat treatment?

The heat treatment is applied to the entire thickness of the product. This can be checked by sawing the board. However, the maximum thickness of the product should not exceed 40mm.

Characteristics and advantages

What is thermowood?

There are several answers to this question. For consumers: Thermowood is a high quality natural material with a strength and durability that surpasses ordinary wood. It resists rot, swelling, warping, and pests, offering a lifespan 10-20 times longer than regular wood without the need for chemical treatment – a 100% environmentally friendly choice. For the tech-savvy: Thermowood is wood that undergoes a specialized treatment process involving high temperatures in oxygen-free chambers, employing gentle multi-stage heating and forced cooling, all achieved without the use of chemicals. For businesses: Thermowood represents an innovative product in the 21st century, already well-established in Europe and developed countries. This market niche continues to evolve, making Thermowood products an excellent business proposition for both domestic markets and export.

What is the difference between thermowood and larch or exotic species?

Aesthetics aren't the only consideration when choosing a wood species for finishing; each species has its own unique characteristics. Larch, an inexpensive option, has the highest moisture resistance of any conifer and its density exceeds that of spruce and pine. However, despite its natural resilience, over time it becomes more brittle and deteriorates. Larch is more prone to splitting, cracking and warping than thermowood. The resin impregnation of larch can lead to bleeding at elevated temperatures, a characteristic not shared by thermo-ash and thermo-fir. Exotic species, particularly cumaru and merbau, are the most expensive finishes. They have excellent density and hardness. Constant contact with a humid environment has given them a natural ’superpower’ to resist decay and delamination. At the same time, exotic cladding and decking is susceptible to deformation – the dense wood begins to warp and even pull out metal fasteners. And although the increased oiliness of exotic species gives them a high density, the ‘tropical guest’ sometimes behaves unpredictably. The board can turn black, because the oils in its structure are not adapted to our climate. We should also mention such a legendary species as teak. It is, in fact, the most resistant material. Teak is unrivalled in its performance characteristics: it does not rot, it does not warp, it does not crack. But it also has its drawbacks. First of all, the price – the real Burmese teak costs about 20,000 roubles /m2. Despite this, a customer may have to wait up to 6 months for their order due to very high demand. It should be noted that there is a high probability of receiving low quality teak from other regions, and this material will not be as stable in use. However, choosing honest suppliers will minimise this risk. Let's return to the more affordable thermo wood. Its main advantage over other species (with the exception of teak) is its relative stability. Unlike larch and exotic woods, thermowood is much less likely to crack and warp. And if you choose to surround yourself with natural materials, it is important to remember that even after heat treatment, the board is still a living ‘organism’. Therefore, by choosing our thermo ash and thermo fir, you will reduce your moral and financial costs many times over, which is acceptable when using natural solid wood. The undeniable value of thermowood is that it does not rot. This means that, with the right care, its lifespan is virtually unlimited.

What is the advantage of thermowood over WPC (wood-polymer composite)?

In today's market, WPC boards have gained immense popularity due to mass production and affordability. They are composed of wood flour and thermoplastic polymer materials such as polyethylene, polypropylene, or polyvinyl chloride. The polymers increase the board's resistance to various negative influences. Despite its popularity, WPC has some drawbacks: • The top layer of the wood-polymer board is susceptible to damage from UV radiation and moisture. • When heated, WPC can release unhealthy vapours due to its polymer content. • WPC products are subject to accelerated wear under the influence of high humidity and temperature changes. • WPC is not resistant to mould and is vulnerable to chemical attack.

What is the difference between thermowood, and normal wood?

Thermo-modification aims to evaporate moisture, resins, and extractive components from wood, making thermowood exceptionally resistant to decay and pathogenic micro-organisms. Thermowood retains the natural beauty of wood, while eliminating its disadvantages. Compared to untreated wood dried without special technologies, thermowood offers increased resistance to environmental factors. Its high density reduces hygroscopicity and prevents moisture absorption, even in direct contact with water. Tests show that thermowood accumulates no more than eight percent moisture when fully immersed in water, demonstrating its resistance to the elements and increasing its versatility. - Stability. Thermowood elements retain their original geometry and dimensions indefinitely, eliminating problems such as twisted boards or irregularities. - High strength. Even the softest species of wood is transformed into a durable, damage-resistant material after high temperature treatment. - Durability. Thermowood products have a much longer lifespan than untreated wood. - Decorative qualities. Thermowood displays the distinctive texture of natural wood, offering vibrant and even colour tones that enhance its decorative appeal. While the main drawback is the higher cost compared to untreated wood, this is outweighed by its almost limitless lifespan. Predictions are that thermowood will become the preferred building and finishing material, replacing outdated alternatives that are susceptible to mould and fungus and pose health risks.

About the technology

What heat treatment technologies are available?

There are several heat treatment technologies for wood. Some of them are designed for soft woods (pine, spruce), others for hard woods (ash, oak, beech). Attempts to heat treat hard species in soft species chambers result in poor quality products with cracks, severe colour heterogeneity, a high percentage of rejects for the manufacturer and in operational problems for the customer. Our focus is on hardwoods (thermo ash, thermo birch) and we process these in American Westwood thermo chambers designed specifically for hardwoods. American Westwood technology This technology was developed in the USA over 20 years ago and has been continuously improved. Westwood equipment is used by the majority of American thermowood producers, with a turnover of more than 200,000 m3 per year. The technology has been refined for heat treatment of valuable hardwoods (ash, oak, beech). Westwood chambers are the most predictable and controllable, ensuring minimal cracking rejects and colour uniformity in finished products. Operating principle: slow heating of wood in an environment of supersaturated water vapour up to a temperature of 220-240°C. Cycle time is up to 48 hours. Finnish Thermowood technology The most popular heat treatment technology. Every year, more than 150,000 m3 of thermowood is produced by companies all over the world using this technology. The main manufacturer and developer of the equipment is Stellac Oy. Among the companies using this technology are Lunawood (Finland), Tekmaheat (Finland), Valutek (Finland), Baschild (Italy), Tretimber (Estonia), Drevmarket (Russia). Characteristics of the technology: thermal treatment of wood in a water vapour atmosphere (protection against combustion) at a temperature of 180-215°C. The process takes 45-96 hours. Thermowood is designed for soft coniferous species, so a high percentage of defects in hardwood (oak, ash) is unavoidable. Dutch PLATO technology PLATO Wood is the developer and manufacturer of this equipment. Their technology is also specialised in softwood and birch. The production process is similar to the Finnish one: the board is gradually heated to 170-210°C in a protective atmosphere of water vapour. The cycle takes 5-8 days. French Rectification Technology The company that manufactures the equipment is called REI and is based in St Etienne. The developer of the technology, the Mining Institute, is located in the same city. The thermal treatment of wood takes place in a protective atmosphere of steam and inert gas (nitrogen) at a temperature of 180-220°C. The process lasts 40-62 hours. The disadvantage of this technology is obvious – the formation of nitrogen salts in the wood is possible. German Menz-Holz technology Developed by the German company Menz-Holz, based on drying wood in an environment of organic (harmless) oils at a temperature of 180-230°C in small chambers (up to 6 m3). The technology is suitable not only for softwoods but also for high quality hardwoods (oak, ash, beech). The cycle time varies between 32 and 54 hours. Danish Fromsseier technology The technology is based on steam drying chambers. It is suitable for soft coniferous woods. The cycle uses the same steam and temperature of 180-220°C, but overpressure is applied in a small (4m3) chamber. The duration of the heat treatment is 2-3 days. Vacuum Plus technology (RF) This technology has been developed and introduced by Vacuum Plus not only in Russian market, but also in many CIS countries. In the first stage, the dry board is vacuum dried at a boiling point of the moisture in the board of 45°C. This gives the whole batch of boards a uniform moisture content of 6%. Then the heat treatment cycle begins at a temperature of 165-190°C. The whole process lasts from 3 to 7 days.

About operation

Will thermowood board burn out in the sun?

Thermowood will burn out naturally if it is not coated with tinted oil. It is the tint that protects it from UV and allows it to retain its colour. However, the board will only burn by a few hundredths of a millimetre and will return to its original appearance after sanding.

Is the installation process the same as for the normal board?

There are a few differences. The main one is that the sealing of the board after the heat treatment process makes it more brittle. It is therefore not recommended to use self-tapping screws and nails without pre-drilling holes. A full list of recommendations for working with thermowood is available on request from our manager.

How and on what is thermowood installed?

The installation methods are the same as for conventional wood (concealed fixing to the joists, exposed fixing, even gluing is possible).

If thermowood is brittle, can it be used for decking?

The brittleness of wood is exaggerated and only becomes noticeable at high modification levels. A number of classical solutions will help to neutralise the problem: - correct selection of wood species; - selection of modes and levels of modification for a specific task; - increasing the cross-section of the finished product; - correct technology of product manufacture. To a greater extent, this is a problem for the manufacturer, not the end user.

Can thermowood be used in residential areas?

Thermowood is used extensively in residential areas, particularly for construction and finishing works. The air and vapour permeability of thermowood is slightly lower than that of conventional wood, which is more than sufficient for normal air exchange.

Why can't thermowood be used in the ground or in contact with the ground?

Information on this subject is contradictory. Most researchers claim that no biodegradation of thermowood has been found in the soil. Tests show its high stability. And the predecessor of thermowood – a tree trunk with a burnt stem – has long been used as a pole for telephone and power lines. But Finnish researchers disagree. According to them, thermowood loses its mechanical properties in the ground. Although the information is ambivalent, it is not recommended to use thermowood in direct contact with the ground.

Can thermowood be used for load-bearing structures in construction?

Thermowood is widely used in construction and finishing works. However, the question of its use as a load-bearing structure has not yet been officially resolved. Preliminary tests of samples have given positive results, but full-scale tests of load-bearing building structures made of thermowood have not been completed and will not be completed in the foreseeable future. The price of the problem is human life and health, therefore it is not recommended to use the material for load-bearing structures.

What is better for a porch or a terrace: ash, birch or pine?

Pine is a soft species and can be crushed under weight. It is not recommended for porches or terraces. A sensible solution is to build them from ash or birch. It should be noted that ash is superior to birch in terms of hardness and more pronounced structure.

How do I sand thermowood?

In the same way as conventional wood. The fact that the sanding surface (e.g. sandpaper) doesn’t become clogged with resin during processing makes it easier to work with thermally treated material.

How do I glue thermowood?

The low water content of thermowood makes it almost impossible for it to absorb moisture. Hence the problems with gluing with water based compounds such as PVA. The best way to ensure a good bond is to press the surfaces for a long time, as the glue needs time to absorb moisture and cure. The percentage of water in the adhesive should be kept to a minimum. Polyurethane based adhesives are recommended. It is important to remember, however, that water is required for quality gluing. A certain amount of wood and air humidity is therefore necessary. It is not recommended to glue normal wood and thermowood together because of their different absorbencies. Such a bond will be unreliable.

Q&A