Most sauna manufacturers recommend using only pure paraffin oil or specialized sealants that they endorse to preserve the wood in saunas. Standard wood sealants and varnish tend to break down in the heat generated by saunas, releasing harmful gases.Continue Reading
Another reason that sauna companies caution against using traditional wood sealants and varnishes is that sauna wood must remain untreated to gradually absorb heat and moisture when the sauna is in use, and then release it as the enclosure cools. The safest way to protect sauna wood is to apply pure paraffin oil, a non-toxic substance, to wood paneling and benches.
Sauna sealants should be natural and not release volatile organic compounds. Although they are not necessary, they do help protect the wood from any mold or mildew that might grow in such a humid environment. Sealants also help prevent discoloration. It is best to wash cedar benches with a solution of water and mild liquid detergent prior to applying the sealant.
The type of wood used to build a sauna is also an important factor in its durability. Wood should be soft and free of knots, which are capable of absorbing more heat and burning people who are using the sauna. The best type of wood for building saunas is Western red cedar, which is not only soft, but naturally resistant to decay.Learn more about Building Materials