When the sauna, bathroom and living spaces are clad with the same wood, a home or holiday house looks calm and consistent. Conditions in these spaces vary a lot, though: in the sauna, temperature and humidity change quickly, while in the living room the air is stable and dry in winter. This article explains how to choose the wood species, panel and surface treatment so that the same surface works in every space.
1. Know what each space demands
We divide interiors into four applications, and every product we make is labelled for each of them:
- Dry interiors: living rooms, bedrooms, hallways and lobbies. Almost any species works, and you can choose the finish freely by appearance.
- Wet room ceilings: moisture rises to the ceiling, but water does not splash directly onto the surface.
- Wet room walls: a more demanding application, where the wood has to withstand splashes and rapid changes in humidity.
- Saunas: the toughest conditions. The wood must be resin-free and conduct heat slowly.
The labels also show whether the wood can be used as it is or whether surface treatment is recommended. They are based on our wood species suitability table.
2. Choose a species that works in every space
If you want the same species from the sauna to the living room, choose it for the most demanding space – the sauna.
- Spruce is light and affordable. In the sauna it needs a sauna protective finish or paraffin oil.
- Aspen is resin-free, almost knot-free and light. It creates a fresh, bright feel and has a mild scent.
- Alder is resin-free with a warm reddish-brown tone that darkens beautifully over time.
- Western red cedar is a light, aromatic speciality wood that suits saunas.
- Thermally modified species, such as thermo aspen, thermo alder, thermo pine and thermally modified radiata pine, are dimensionally stable and dark. They are especially well suited to wet rooms and saunas.
Remember two exceptions: thermally modified aspen is not suitable for a continuously heated sauna – choose thermally modified alder or thermally modified radiata pine instead, which we offer in a wide range – and untreated pine releases resin in the sauna. The tone changes over time: light wood darkens and dark thermally modified wood lightens.
3. Choose the profile, width and direction
Narrow panels create a rhythmic surface, wide panels a calm one. A sharp-edged profile casts strong shadows, a rounder one gives a softer look. A batten panel looks like separate battens but installs like a panel.
Different profiles of the same species can set spaces apart without breaking the whole.
Consistency comes from running the panels in the same direction from one space to the next. Or make the sauna a space of its own by switching from horizontal to vertical panels. On ceilings, run the panels in the direction of the light.
Panels can be installed horizontally, vertically or diagonally.
4. Match the finish to the space
The same wood can get a different treatment in each space, as long as the tone stays the same:
- Sauna: spruce, aspen and alder with a sauna protective finish or paraffin oil; thermally modified species with paraffin oil. A sauna protective finish can also be tinted.
- Wet rooms: a moisture-resistant finish made for wet rooms.
- Dry interiors: paint, oil, wax or lacquer. A semi-transparent finish leaves the grain visible; opaque paint gives an even colour. For panelled ceilings, choose a matt paint.
Good to know: light wood darkens and yellows in daylight. To keep a light tone, choose a white-pigmented or UV-protective, non-yellowing product.
You can also order the panels pre-finished. When the treatment is applied at the factory before installation, the tongues and edges are treated too, so no light stripes appear at the joints when the wood shrinks in winter.
Treat new wood before fixing it, so the tongues and ends are treated as well.
5. Install it right and the surface stays neat
- Let the panels acclimatise in the installation space for 1–2 weeks at about +20 °C and 40–60% relative humidity.
- Allow 10–15% for waste and choose panels at least 5 cm longer than you need.
- Fix the battens at right angles to the panels, at most 600 mm apart.
- Allow for movement: about 10 mm between the panel and the wall in dry spaces, about 15 mm in the sauna.
- In the sauna, install horizontal panels tongue up, leave a ventilation gap behind the panels and always use stainless steel fixings.
Vertical battens for horizontal panels, horizontal battens for vertical panels.
Face nailing is the easiest and most secure method. Panels with a concealed-nail tongue are fixed through the groove.
Example combinations
Need help choosing?
We send samples of wood species and finishes so you can see the tones in your own light. Contact our sales team, explore our wood species or browse the product catalogue.