Can You Use White Cedar for a Sauna?

Saunas are a type of hot-air, low-humidity bath that originated in Finland. Unlike steam baths, which rarely rise above 154 degrees Fahrenheit and have a humidity of around 80 percent, the average temperature in a sauna ranges between 175 and 210 degrees Fahrenheit with a humidity of less than 20 percent. Sauna interiors are constructed out of wood, because wood is more comfortable to sit on in hot temperatures. Several types of wood can be used, including white cedar.

Cedar is a popular wood choice for saunas built in North America. It weathers well, the oils inside the cedar make it resistant to decay, and it releases a pleasing aroma that adds to its attractiveness. Because it's lightweight, it's not as apt to crack as heavier woods are. Cedar also keeps its original shape better than some other woods and won't warp or curve under the harsh sauna atmosphere. Cedar is a better insulator than most other woods, too, because it contains more air spaces. This means the wood won't be too hot to sit on! Some woods can cause skin burns in the sauna when the pitch in them heats up, but cedar produces little or no resin.

There are many types of cedar. Some of them are available only in certain regions. However, both red and white cedars are commonly used when building saunas. Western red cedar is usually more available, but white cedar can cost less because of shipping charges. Both western red and eastern white cedars are moderately soft, lightweight woods that don't shrink much. Southern red cedar is another variety that's very aromatic and repels insects. It's a straight-grained wood that's easy to work. Other types of white cedar include Atlantic white and northern white. Both of these woods are very resistant to decay, but northern white cedar doesn't hold nails or screws very well.

Although western red cedar and eastern white cedar are closely related genetically, there are several differences between them. White cedar trees are smaller and produce a lighter-weight wood that's weaker than red cedar wood. In addition, it contains more knots. Both types of cedar are pretty much the same when it comes to their ability to resist decay. However, red cedar is a stronger wood that has a better ability to hold nails and screws.

Traditionally, Nordic white spruce is used to build saunas in Finland. Although cedar wood is popular in North America, pine, spruce and hemlock are also used, and they often cost less than cedar. Domestic spruce and pine often have large, loose knots that fall out of the wood as it dries. Other woods that can be used include clear aspen and clear all-heart redwood. Redwood is very expensive, however, and darkens quickly. Hardwoods such as oak, ash and maple aren't usually good choices for saunas because they're too dense. Cedar and pine resist decay better and absorb moisture better than hardwoods as well.