THE LOOK AND FEATURES

Wood cannot be ignored when building a sauna. For these purposes, it must not be resinous and should have the highest coefficient of heat conductivity and the ability to absorb steam. It must be well manufactured and not change form even at 100°C. From experience we can state that in our conditions spruce is the ideal wood to use, and we always recommend builders and manufacturers of sauna cabins to utilise its highly practical qualities. Although such qualities may not fully compare with those of, for example, northern fir or Canadian larch, when taking into consideration its lower cost, it is very suitable as panelling. Today people do not pay attention so much to the regular structural appearance of panelling, but rather to the rich natural designs of wood. Many manufacturers of saunas, however, are able to utilise only the small financial difference between imported and domestic wood, especially concerning the African wood abaschi, which is suitable for making sauna benches.

SPRUCE WOOD

Many builders are afraid to use spruce because it exudes resin. In practice, it has been shown that this happens in a limited form only occasionally, and only if sap channels are disturbed when it is being cut. Then, in hot conditions it exudes several drops of resin and then it finishes. The exuded resin can easily be scraped off. Pine and spruce act quite differently. These woods are highly resinous and in a heated sauna cabin the resin diffuses so that within a short time, a sort of polish is created on the panelling. This naturally impedes the absorption of humidity and so such panelling loses its basic functions and must often be sanded down.

SOFT WOOD OF LEAFY TREES

A similar situation occurs with the use of softer deciduous wood. It is porous, does not have the necessary ability to absorb humidity and degrades far more quickly than spruce. With harder deciduous wood, the absorption ability is even further limited and its hardness does not prevent degradation. Deciduous wood is not sufficiently resistant to heat. (I had the opportunity to see beech panelling after 10 years of use, and I thought I was in a gingerbread house as the wood was burnt to a brown colour and was crumbly to the touch.)

POPLAR WOOD

One exception to these types of wood for wall and ceiling panelling is poplar, which has proven absorption qualities, basically does not differ from spruce and is mainly prized for its attractive appearance. It does not appear in Scandinavian sauna brochures, as it does not grow there. Scandinavian, Canadian and African wood, which are used by foreign and some Czech firms, are not the only wood that can be used, even though they can be cheaper. Wood here has even lower levels of resin (e.g. poplar.) I am very glad that I have Czech spruce, even with knots, as panelling in my sauna. It is my silent friend, I look at it whilst warming up as if it were a link with multi-hued nature, best represented by wood, and it shortens the time to warm up. My grandchildren count the number of boards and improve their school marks! Austerely arranged boards are best seen around a football pitch as a fence.

Source: MUDr. A. Mikolášek, Czech sauna, (GRADA Publishing, 1999)