Our Thermo Aspen interior cladding boards are premium European timber, thermally modified using only heat and steam—no chemicals—to enhance stability, durability, and appearance in sauna environments.
Featuring the STS profile, a specialised cladding system widely used for sauna walls and ceilings, it is characterised by clean, straight edges and a precise tongue-and-groove joint, creating a smooth, continuous surface with a refined linear finish.
The thermal process permanently refines the wood’s cellular structure, improving dimensional stability and resistance to warping, twisting, and moisture movement, ensuring long-lasting performance in high heat and humidity.
Naturally pale in its original form, the aspen is transformed through heat treatment into a warm, golden-brown timber with soft tonal depth, adding warmth and a premium aesthetic to sauna interiors.