What is the best wood for sauna benches? | Lauta.fi

The benches are where you spend the best moments in the sauna, and they are in constant contact with bare skin. Good bench wood does not get too hot, does not release resin and withstands rapid changes in temperature and humidity. This article explains which wood species suit sauna benches, how to size and fix the benches, and how to keep them beautiful for years.

What makes good bench wood?

• Low thermal conductivity. Wood that conducts heat slowly feels cool even in hot steam.
• No resin. Resinous wood releases hot, sticky resin as the sauna heats up.
• Moisture resistance. The benches get wet and dry every time you use the sauna, so the wood has to cope with the changes without cracking.

Wood species for sauna benches

• Aspen is a resin-free, light and almost knot-free hardwood. It conducts heat slowly and has a mild scent, which makes it many people's first choice for benches. For example aspen bench board 28x90 and aspen bench board 28x120.
• Alder is resin-free with a warm reddish-brown tone. It also feels pleasant against the skin.
• Thermally modified species, such as thermo aspen, thermo alder, thermo pine and thermally modified radiata pine, are dark and dimensionally stable. Thermal modification is carried out at high temperature using steam, and it removes the resin. For example thermo pine bench board 26x118 SHP.

Continuously heated sauna: thermally modified aspen is not suitable for a continuously heated sauna. Choose thermally modified alder instead – its tone is close to thermo aspen – or thermally modified radiata pine, which we offer in a wide range of products.

Thermally modified radiata pine: newly installed radiata pine can have a strong smell at first. Ventilate the sauna well, and the smell will fade.

Avoid untreated pine. Resin seeps out when the surface heats up. Thermally modified pine works well in the sauna because thermal modification removes the resin.

Width and direction define the look

Narrow boards create a traditional, rhythmic surface; wide boards a calm, modern one. You can use one or several widths and combine different species. A wide glued plank bench gives a minimalist look – for example aspen plank bench board 43x200 or alder plank bench board 43x200.

Match the benches to the colour, width and profile of the wall panels. Benches are usually left in their natural colour, so the species largely defines the look of the sauna.

Size the benches correctly

Good steam comes from benches at the right height.

• Leave 100–120 cm between the upper bench and the ceiling.
• The height difference between the upper and lower bench is usually 40–45 cm.
• The upper bench is usually 55–60 cm deep.
• Allow at least 60 cm of seating per person.
• Check the safety distances between the heater and the benches in the heater manufacturer's instructions.

Fix the boards from below

• Let the boards acclimatise in the sauna for 1–2 weeks before installation.
• Support the benches properly. Fix the brackets to the wall battens or to extra supports installed behind the panels. Support long benches in the middle as well.
• Leave a gap between the bench and the wall (about 5–10 mm) and between the boards, so air can circulate and the wood can dry.
• Always fix the boards from below with stainless steel screws, so no screw heads end up on the seating surface where they would get hot. Pre-drill the holes so the boards do not split.

Always treat the benches before use

Temperature and humidity in the sauna change quickly and a lot, so benches always need a surface treatment. Treat them with paraffin oil or sauna wax before the first use. For thermally modified benches we recommend paraffin oil only.

• Paraffin oil soaks into the wood, makes it harder for water to penetrate and repels dirt. It slightly deepens the tone of the wood.
• Test the oil on an inconspicuous spot first to see how the tone changes.
• Apply the oil with a sponge or cloth along the grain, and treat the board ends too. The surface is ready for the sauna after about 12 hours.

How to keep the benches beautiful

• Dry the sauna after every use. Lift removable bench sections upright and keep the heater on for about half an hour with the door closed and the vent open.
• Use a bench towel, and take textiles out of the sauna afterwards.
• Do not hose down the benches after every use. Wash them 1–4 times a year depending on use, with a mild sauna cleaner and a soft brush along the grain.
• Renew the oil treatment 1–5 times a year, when the surface starts to look dull.
• Tighten the screws once or twice during the first year, as the wood shrinks.

Choose your bench wood with a sample

We send samples of bench boards so you can see the tone in your own sauna. Contact our sales team or read more about our wood species.