Tips
Thermally Treated Wood in Pools and SPA Areas: Resistance, Maintenance and Durability
Materials used in pool and SPA environments are exposed to some of the most demanding conditions. Constant humidity, temperature fluctuations and frequent use mean that surfaces must be both durable and visually consistent over time. This is one of the main reasons why thermally treated wood is increasingly chosen for these spaces.
In such environments, not only flooring but also wall finishes play an important role. If you are planning a sauna or relaxation area, it is worth considering how your chosen sauna cladding will perform over the years and what level of maintenance it will require.
Why thermally treated wood performs well in humid environments
Thermally treated wood is modified using heat and steam, which changes its internal structure and reduces its sensitivity to moisture. As a result, the material absorbs less water and reacts less to changes in humidity.
This is particularly important in SPA and pool areas, where untreated wood can expand, contract or even deform over time. Thermally modified timber remains more stable, allowing surfaces to maintain their shape and appearance for longer periods. This makes it a reliable option for wall cladding, where even small changes can become visually noticeable.
Resistance to temperature changes
Saunas and SPA areas often experience strong temperature variations. Surfaces may be exposed to heat and then quickly return to cooler and more humid conditions. These changes can affect many materials over time.
Thermally treated wood handles these conditions more consistently due to its improved structural stability. It reacts less to temperature shifts, which helps maintain the integrity of the cladding. This is one of the reasons why it is used not only outdoors, but also in interior spaces where humidity and temperature levels vary.
Natural feel and visual appearance
In SPA and wellness environments, comfort is just as important as durability. Natural wood brings warmth and a calm atmosphere that other materials often cannot replicate. Thermally treated wood retains its natural texture, creating surfaces that feel pleasant and visually balanced.
This is especially relevant in sauna interiors, where materials are in direct contact with people. Well chosen sauna cladding helps create a space that feels both functional and comfortable, supporting the overall experience.
Maintenance and long-term use
One of the most common questions is related to maintenance. Thermally treated wood does not require complex treatment, but certain care considerations still apply, especially if a specific appearance is desired.
In sauna and indoor SPA areas, surfaces are often left untreated or finished with products suitable for high temperatures. Proper ventilation and correct installation are essential, as they directly influence long-term performance and durability.
Durability in demanding conditions
The durability of thermally treated wood becomes most evident in challenging environments. Where untreated wood may lose stability more quickly, thermally modified timber remains consistent. This makes it suitable for both poolside areas and sauna interiors, where resistance to moisture and long-term stability are equally important.
Long service life depends not only on the material itself, but also on how it is applied. Properly selected and installed sauna cladding can maintain both its structure and appearance for many years.
What to consider before choosing materials
When selecting materials for SPA or sauna spaces, it is important to look beyond initial appearance. Consider how the material will behave in everyday use, how it reacts to moisture and heat, and how it will look after years of exposure.
Thermally treated wood offers a balance between durability and natural aesthetics, making it a versatile solution for both walls and other interior surfaces.
If you are planning a pool or sauna project and want to choose a solution that performs reliably over time, the ESSPO Wood team can help you select the most suitable sauna cladding based on your environment, design and expected use.