Exterior Finish for Barrel Sauna

The cedar used in our barrel saunas is a great wood for any outdoor construction. It’s made up long fibrous strands that are full of cellulose. This gives it great insulation value but also gives it stability against warping and twisting. However, like any wood the exterior of the wood is subject to an oxidation reaction when directly exposed to sunlight and oxygen. As such when cedar is left in the sun it will bleach out its natural red color causing it to turn a light grey color.

Type of sealant to use- If you choose to apply a sealant, you should consider the quality you use. A properly sealed sauna requires at least two coats, and this can take a half a day of labor. So, spending a little extra on the quality will mean ultimately more year’s in-between re-applications! Sikkens and Cabot are two of the higher end sealants that are preferred choices for cedar and log homes.

The sealant will always come with a tint. It is the tint that provides the UV protection. There are many choices, so it is best to ask to see a sample of the sealant on the type of wood you choose. A good paint supply shop should have samples of each color on cedar as well as pine or other popular outdoor woods. When buying a stain we recommend a semi-translucent stain versus a solid stain. The difference is that a semi-transparent stain will still allow the wood grains and natural color of the wood to show through. A solid stain will take the appearance of paint, completely hiding the natural grains and colors of the wood.

Never stain the interior of the sauna! A sauna room whether indoor or outdoor sauna should never have an exterior stain applied to the inside. Exterior stains tend to off gas and can produce Volatile Organic Compounds or VOC. This can cause health issues and should be reserved for the outside of the sauna. There are interior preservatives for the interior of a sauna that can be used. These are 100% water based and designed to be 100% VOC free and will never off gas especially in the high temperature environment of an interior sauna room.

The number of years in-between coats will vary depending on the quality of the exterior sauna stain you purchase. However, the location of the sauna and the local environment will also influence the ageing effects on the wood. A sauna in direct sunlight will tend to need more frequent applications. 

Whether you choose to stain the exterior finish of a barrel sauna or not, the choice is ultimately up to you. If you love the beautiful color of Western Red Cedar and want to keep the rich color then definitely stain the wood. If you want to minimize your labor or create the grey aged look then let the barrel sauna room naturally age!