Thermo Spruce, Picea Abies & Thermo Pine, Pinus Sylvestris

Are thermally modified spruce and pine good wood types for building a sauna?

Many sauna builders wonder if spruce and pine are good choices for sauna cladding and benches because of the knots and weeping resin typical for these wood types? Thermally modified spruce and pine are great choices for a sauna if you like the rustic look of coniferous sauna woods that spruce and pine create but are looking for something more durable.

Thermo Spruce vs Thermo Pine:

Our thermo spruce is created from thermally modifying spruce, Picea Abies in Latin. Spruce is a coniferous, evergreen wood that belongs to the pine family. The natural tone of spruce is light, almost white. Spruce does not weep as much resin as pine, but it can split more easily in its natural form. It is popular as a material for the exterior walls of a sauna.

After spruce is thermally modified, it gains a durability class 1 and becomes more resistant to rot and decay. As other thermowoods, spruce takes on an attractive, darker colour after it has been treated with heat and steam. Thermo spruce has a natural aesthetic, with a light golden colour. As a raw wood type, pine has similar qualities to spruce and is also commonly used as the outer sauna wall cladding. Pine is a widespread coniferous tree that grows in Asia and Europe. Pine makes an excellent wood for thermal modification. Thermo pine has a unique look, which is slightly darker brown in colouring when compared against thermo spruce.

Both thermo spruce and thermo pine have a pleasant, toasted scent, which many sauna enthusiasts find an important aspect when choosing a wood type for their authentic Finnish home sauna. We recommend treating both thermo pine and thermo spruce sauna wood cladding and benches with paraffin oil to deepen the darker tones and added layer of protection. Finnmark’s thermally modified pine and spruce are sourced from grade A and B timber grown in the Baltic and Nordic countries.

Thermo pine and thermo spruce are used for sauna products including:

• Sauna wood cladding
• Sauna benches
• Sauna Bench framing (Thermo Spruce)
• Sauna Battens
• Sauna Heater Guards
• Barrel Saunas

Thermo Spruce is available in the following sauna wood profiles:

• STP Profile Tongue and Groove Cladding: 15mm thick by 90mm wide
• Sauna Bench Framing Timber: 57mm thick by 57mm wide

Thermo Pine is available in the following sauna wood profiles:

• Kallio Tongue and Groove Cladding: 15mm thick by 90mm and 118mm wide
• Sauna Wood Bench Board: 26mm thick by 92mm wide
• Rainscreen Rhombus Sauna Batten: 26mm thick by 67mm wide

When you are ordering your sauna wood cladding and benches, you should consider the wastage allowance. We recommend a wastage allowance of at least 20% for thermally modified pine and spruce timber products due to its slightly brittle nature when being rough handled, as well as it’s cracking knots and occasional end splits. 

You can find our array of thermo pine and thermo spruce sauna wood products below: