Every sauna design is different – some are focused on practicality while others offer more decorative appeal. Whatever choices you make for your sauna, there are certain universal principles, like using woods that don’t overheat or secrete resin for the benches and selecting interior materials that are resistant to heat and moisture.
We also use thermal-modification of timber to enhance its durability, moisture resistance, and stability. Our highly specialized process also transforms the look and feel of this natural building material to add character to your sauna. Some woods retain their cozy and warm light brown tones, while others – like magnolia, radiata pine, and ash – darken for an elegant finish. This process in completely chemical-free. Wood is being modified with just heat and steam.
Here’s a guide to the ten most popular woods we provide for use in the sauna.
Common aspen (Populus tremula)
Common aspen is a deciduous tree in the willow family that grows around Europe and Asia, as well as northern Africa. It makes an ideal material for sauna benches because it doesn’t secrete resin, create splinters, or get too hot. Its characteristic light tone and smooth texture also give it an attractive look and make it perfect for painting, so it can be used for interior and exterior walls too. We offer a number of interior sauna elements in both natural and thermally modified aspen.
Thermory brushed pine and natural aspen sauna
Western red cedar (Thuja plicata)
The western red cedar, an evergreen coniferous tree in the cypress family that is also known as Pacific red cedar, is perfect for sauna benches and interiors because it doesn’t secrete resin or overheat, and it is also water repellent. Growing primarily in the western part of North America, Red cedar is known for its pleasantly rich aroma and its exquisite reddish color with a range of natural shades, which also make it an attractive option for exterior paneling.
Canadian hemlock (Tsuga canadensis)
The wood of Tsuga canadensis, also known as Canadian hemlock or eastern hemlock, is soft, with a coarse grain and a light buff color making it well suited to exterior walls. As well as being durable and knot-free, wood from this coniferous North American tree of the pine family is ideal for use inside saunas because it doesn’t warp and it radiates heat evenly. Canadian hemlock also produces a delicate, relaxing aroma.
Common alder or black alder (Alnus glutinosa)
Thanks to its reddish tone and pleasant texture, wood from the common alder, also known as black alder, is popular as a finishing material in saunas. Growing around Europe, southwestern Asia and northern Africa, this perennial deciduous tree from the birch family produces a hardy, water-repellent wood that doesn’t overheat. We use alder to produce a variety of interior sauna materials and products, with thermally modified and brushed finishes available.
Thermory alder sauna
Scots pine (Pinus sylvestris)
Scots pine is a coniferous tree in the pine family, and in saunas it is most commonly used for outer walls. It is the most widespread species of pine, grown across Europe and Asia. The wood responds well to thermal modification to produce an exclusive look, and we additionally offer sauna materials in natural, untreated Scots pine. The natural pattern of the timber can be highlighted using a special brushing technique.
Norway Spruce (Picea abies)
The wood of the Norway spruce, an evergreen coniferous tree of the pine family also known as European spruce, is almost white, with a light yellowish undertone – it is one of the lightest colored coniferous woods. Grown in northern, central, and eastern Europe, Spruce is often used as timber, and for saunas it is generally preferred for exterior walls. We can also brush the wood to further enhance its attractive natural pattern.
American ash or white ash (Fraxinus americana)
American ash is a perennial deciduous tree in the olive family that grows in North America. It produces a wood that is valuable, durable, strong, and decorative, with an attractive texture that beautifully complements exterior sauna walls. Our thermally modified ash takes on a dark brown color, giving an exclusive look, and it can be brushed to further highlight its distinctive pattern.
Thermory ash sauna
Radiata pine (Pinus radiata)
The radiata pine is a coniferous tree of the pine family. Its rapid growth and excellent quality make it among the most cultivated coniferous species in many parts of the world. With no exposed knots, the wood doesn’t secrete resin, splinter, or overheat, making it great for sauna benches. Wide boards, brushing to bring out the natural pattern, and the darker hue from thermal modification offer a touch of luxury for interior and exterior paneling too.
Thermory radiata sauna
Poplar, part of the willow family, is naturally pale yellow in color, with a smooth texture. Common in the Northern Hemisphere, it belongs to the same genus as aspen (Populus tremula), and it’s similarly ideal for sauna benches and interiors – the wood has no exposed knots and it doesn’t splinter, secrete resin, or overheat. The warm look from thermal modification and the wide boards make for a cozy, luxurious finish that also suits exterior walls.
Magnolia (Liriodendron tulipifera)
Magnolia, also known as the tulip tree, belongs to the magnolia family and has a creamy, golden hue with darker areas, and a characteristic pattern with similarities to ash and radiata pine. Along with its low density, this makes it perfect for sauna benches, interiors, and exterior paneling. Wide boards and the dark shade achieved by thermal modification give this wood, which can be found in parts of North America, a luxurious, exclusive finish.
Thermory magnolia sauna