Sauna wood types

Walls

Finnleo says Nordic white spruce is the traditional sauna interior wood, chosen for its light colour, clean lines and scent. Finnleo uses Nordic white spruce as its standard, offers hemlock and cedar, and uses abachi, hemlock or cedar for benches and backrests. (Finnleo)

Thermory describes western red cedar as resin-free, slow to overheat and water repellent, with a rich aroma and reddish colour. Thermory describes Canadian hemlock as durable and knot-free, and says it does not warp inside a sauna.

Almost Heaven describes its rustic red cedar as naturally weather-resistant, with tight knots and a sweet aroma. Almost Heaven notes that Nordic spruce, as a conifer, can show a small amount of pitch (sap) in the heat, which does not return once scraped off. (Almost Heaven Saunas; Almost Heaven Saunas)

Benches

Thermory's general rule is bench woods that do not overheat or secrete resin, and interior materials that resist heat and moisture. Thermory recommends aspen for benches because it does not secrete resin, splinter or get too hot.

Heat-treated wood

Thermory says it thermally modifies sauna timber with only heat and steam, and no chemicals, for durability, moisture resistance and stability.

Harvia says heat-treated wood is a little more fragile and porous than untreated wood, so it takes up moisture more easily.

Moisture

Harvia rates spruce best at handling moisture, followed by pine, alder, aspen and heat-treated alder.

Read next

• Sauna bench layout
• Sauna maintenance
• Sauna insulation and vapor barrier