Specification
Wood built to last. The timber and materials used in the Regenerum sauna line.
Materials
Two woods, one sauna
We build the shell and floor from ThermoWood – thermally modified spruce of exceptional durability. Benches are premium aspen wood, with aspen headrests (2 pcs.) – pleasant against the skin even at high temperatures.
Shell & floor
ThermoWood
We build the sauna shell and floor from ThermoWood – thermally modified spruce. It is the same fine spruce, heat-treated at 180–230°C using only steam, with no chemicals. The result is outstanding moisture resistance, dimensional stability and a material made for the demanding conditions inside a sauna for many years.
Made from this wood
Sauna shell
Made from this wood
Floor
Benches & aspen headrests (2 pcs.)
Aspen
We make the benches from premium aspen wood and include aspen headrests (2 pcs.) as standard – a gentle wood that's remarkably pleasant to the touch and stays cool enough not to burn skin even at high temperatures. Aspen has a smooth, even grain with little resin, so it won't mark your skin and sheds moisture well, staying fresh for years.
Made from this wood
Benches & aspen headrests (2 pcs.)
ThermoWood
ThermoWood – thermally modified spruce made for premium saunas
In RoyalSauna Regenerum saunas we use the highest-quality ThermoWood – spruce refined through advanced thermal modification. It combines the natural beauty of spruce with exceptional durability. Treatment uses only high temperature (180–230°C) and steam – with no chemicals whatsoever. The result is a material with far better performance, ideally suited to the demanding conditions inside a sauna.
Natural beauty and outstanding durability
The ThermoWood process significantly increases resistance to moisture, temperature swings and the elements. With reduced absorbency the material stays stable for years, resists warping and is far less prone to cracking or twisting. High heat also removes resin, so the surface stays attractive and comfortable in use.
Why ThermoWood?
100% natural
No chemical impregnants or additives – only wood treated with heat and steam.
Exceptionally durable
Resistant to moisture, fungi, mould and changing weather conditions.
Dimensionally stable
Up to 90% less prone to twisting and deformation than traditional timber.
Better insulation
Up to 25% better thermal insulation – greater energy efficiency and heat that lasts longer.
Insect resistant
Low moisture content effectively limits the risk of pests.
Beautiful, even colour
Thermal treatment gives the wood a deep, refined tone and improves the durability of protective finishes.
Ecological
Sourced from renewable forests and fully environmentally friendly.
Safer
The altered structure increases fire resistance compared with traditional timber.
A material built to last
Choosing ThermoWood means investing in timber made for long-term use. It is valued in premium construction for durability, elegant looks and resistance to demanding conditions. In RoyalSauna Regenerum saunas it preserves not only exceptional aesthetics, but above all comfort, safety and reliability through years of everyday use.
Construction
What a sauna is built from
We break the sauna down into its parts – each element is timber matched to its role.
Sauna shell
ThermoWood (thermally modified spruce) – bent, multi-layer arches that give the sauna its signature rounded shape.
Walls
ThermoWood (thermally modified spruce) – solid walls with enhanced resistance to moisture and temperature swings.
Benches
Premium aspen wood – smooth and cool to the touch, comfortable even at high sauna temperatures. Aspen headrests (2 pcs.) included as standard.
Floor
ThermoWood (thermally modified spruce) – flooring timber that won't burn your feet.
Sauna shell
ThermoWood (thermally modified spruce) – bent, multi-layer arches that give the sauna its signature rounded shape.
Walls
ThermoWood (thermally modified spruce) – solid walls with enhanced resistance to moisture and temperature swings.
Benches
Premium aspen wood – smooth and cool to the touch, comfortable even at high sauna temperatures. Aspen headrests (2 pcs.) included as standard.
Floor
ThermoWood (thermally modified spruce) – flooring timber that won't burn your feet.