The Best Wood Types For Outdoor Saunas

The Best Wood Types For Outdoor Saunas

At Backcountry Recreation, we offer a range of barrel saunas that are designed to provide a relaxing and rejuvenating experience. We understand that the choice of wood is an important factor when it comes to selecting a sauna, and we are proud to offer a variety of high-quality wood types to suit your preferences.

Clear Red Cedar (A or B & Better Grade)

Clear Canadian Western Red Cedar also known as A & Better Cedar, is a type of Western Red Cedar that is mostly free of knots, but not completely knot-free. For a knot-free option, Clear Vertical Grain Cedar is available, but it can be hard to find and expensive.

Western Red Cedar is one of the most valuable wood species commercially. Its outstanding working properties, including its natural resistance to termites, rot, and decay, make it an excellent choice for outdoor applications. Its attractive dark color, lightweight, and soft texture make it ideal for various uses, such as roof shingles, exterior siding, cladding, decking, greenhouses, and saunas. Although there are many grades of red cedar saunas available, Backcountry Recreation only uses the highest quality clear grade cedar, ensuring that our saunas are of the highest quality.

Thanks to its flexibility and versatility, Western Red Cedar is a popular choice for a wide range of applications. However, Backcountry Recreation only uses the best clear grade cedar available, making our saunas stand out from the rest.


  • Lightweight and easy to work with
  • Has a natural resistance to rot, decay, and termites
  • Can be sanded to a smooth satin finish
  • Planes and shapes well
  • Glues easily
  • Contains natural semisynthetic substance that is capable of killing and inhibits the growth of microbes
  • Provides an intense signature cedar aroma
  • Has unparalleled beauty and attractive dark color
  • Can last for many years when properly maintained
  • Suitable for a variety of outdoor applications


  • Can be relatively expensive compared to other types of wood
  • Some people may be allergic to cedar
  • May require regular maintenance to preserve its natural beauty and properties
  • Can be susceptible to staining or discoloration if not properly maintained or protected from weather conditions

Scandinavian Thermowood

Scandinavian Thermowood is a type of Scandinavian softwood that undergoes a heat-treatment process in special chamber kilns for up to 96 hours at temperatures between 180 and 230 degrees Celsius. During treatment, steam is used as a protective gas to prevent the wood from splitting or becoming damaged. This process brings about both chemical and structural changes that alter some of the wood's characteristics and qualities.

One of the most significant benefits of Thermowood is its dimensional stability. The intense heat that the wood is subjected to during production causes all moisture and resin to be removed from the timber, resulting in a wood that doesn't react as severely to changes in humidity as untreated wood. This decreased risk of swelling, cracking, and shrinkage allows Thermowood to maintain its shape far better. Moreover, it doesn't secrete sap or resin even in high temperatures, making it an ideal choice for various applications.


  • Dimensionally stable due to low moisture content, minimizing the risk of warping or twisting
  • Resistant to decay and insects due to the heat treatment process
  • Reduced risk of splitting and cracking due to the release of tension during the heat treatment process
  • Increased durability and lifespan compared to untreated wood
  • Reduced need for maintenance and preservation treatments
  • Increased thermal insulation properties
  • Non-toxic and environmentally friendly production process


  • Can be more expensive than untreated wood due to the specialized production process
  • Limited availability in some regions
  • Requires specialized tools and expertise to work with due to the increased hardness and brittleness of the wood after treatment
  • Limited color options as the heat treatment can cause color variation or a uniform light brown color
  • Not suitable for all types of woodworking projects due to the altered characteristics of the wood after treatment

Select Tight Knot (sometimes called heritage or rustic cedar)

Select tight knot cedar is a type of cedar that contains knots, which are areas of the wood where a branch has grown. While some people may find the appearance of knots to be aesthetically pleasing, they can actually have negative impacts on the quality and durability of the wood. When used to build a sauna, the knots can come loose and fall out over time, leaving the sauna with unplanned ventilation holes. This can be especially problematic in terms of heat retention and can make the sauna seating almost unusable.

Furthermore, the sauna will expand and contract over time due to changes in temperature and humidity. The knots in select tight knot cedar can exacerbate this issue, as they are denser than the surrounding wood and can create uneven expansion and contraction patterns. This can cause the wood to warp, crack, or split, reducing the longevity of the sauna.

While select tight knot cedar may be a cheaper option compared to clear cedar, it is important to consider the trade-offs. A clear cedar sauna may cost more upfront, but it will be of higher quality and have a longer lifespan. Additionally, clear cedar is less likely to contain knots, making it a more stable and reliable material for saunas. Ultimately, investing in a higher quality sauna will provide a better return on investment in terms of beauty, longevity, and long-lasting enjoyment.

Remember, what you save in price, you'll lose in longevity, beauty, and long-lasting enjoyment.


  • Lower cost compared to clear cedar, making it a more affordable option for those on a tight budget.
  • The knots give the wood a rustic and natural look, which may be desirable for some.
  • Can be suitable for walls, as it still retains some of the natural properties of cedar such as being naturally resistant to rot and insects.
  • Can be a good option for those who are not as concerned with longevity and are willing to replace the wood over time.


  • Not as high quality as clear cedar, with knots that can come loose and fall out over time, potentially causing ventilation holes in the sauna.
  • The knots can be very dense and heat-retentive, which can cause discomfort and potentially burn skin.
  • Not as aesthetically pleasing as clear cedar due to the presence of knots and potential inconsistency in the wood's appearance.
  • May not last as long as clear cedar, requiring more frequent replacement and maintenance.

Western Hemlock

Western Hemlock, when it comes to building a sauna, hemlock falls short in comparison to cedar. Hemlock is known for its tendency to splinter, making it unsuitable for use in a sauna. Cedar, on the other hand, is both pliable and strong, making it a superior choice for all aspects of sauna construction. Hemlock is better suited for framing use within a building, such as a home or barn. Its straight grain can cause it to splinter and even snap, making it an unwise choice for building sauna benches. Unlike cedar, hemlock benches are uncomfortable and rough, offering an unpleasant sauna experience.


  • Hemlock is a more affordable option compared to cedar.
  • Hemlock has a natural resistance to decay and rot, which makes it a durable option for outdoor use.
  • Hemlock has a straight and uniform grain pattern, which can give a more consistent look to the sauna.
  • Hemlock is lightweight, which makes it easier to work with during construction.
  • Hemlock has a pleasant aroma, which can add to the sauna experience.


  • Hemlock is prone to splintering, which can make it a less comfortable option for sauna benches.
  • Hemlock may not be as pliable and strong as cedar, which can affect the longevity of the sauna.
  • Hemlock may not have the same level of natural resistance to insects and pests as cedar, which can lead to potential problems over time.
  • Hemlock may require more maintenance than cedar to maintain its appearance and durability.
  • Hemlock may not have the same aesthetic appeal as cedar, which can be a drawback for those who prioritize the look of their sauna.

Pine or Fir

The pine or fir group, consisting of Engelmann Spruce, Lodgepole Pine, and Subalpine Fir, may seem like a versatile option for construction, but it has its limitations. While SPF boasts a high strength-to-weight ratio, it is not the best choice for outdoor applications when left untreated. This is due to its tendency to warp, rot, and decay when exposed to the elements. Despite being extensively used in the flat-packed furniture industry, SPF falls short when it comes to outdoor construction projects, where durability and resistance to moisture are essential. So, while it may be suitable for interior finishing, pallets, and packaging cases, SPF is not recommended for outdoor use.

  • High strength-to-weight ratio, making it a good choice for structural support
  • Affordable compared to other types of wood
  • Easy to work with, making it a good choice for DIY projects
  • Suitable for flat-packed furniture, modular houses, interior finishing, boxes, pallets, packaging cases, and concrete formwork
  • Widely available in North America


  • Not the best choice for outdoor applications when left untreated due to low natural resistance to moisture and decay
  • Requires regular maintenance and treatment to protect against weathering and rot
  • Can warp, split, or crack over time due to changes in temperature and humidity
  • Not as durable or long-lasting as other types of wood commonly used for saunas, such as cedar or thermowood
  • Can have a more rough or rustic appearance compared to other woods

Nordic Spruce

Nordic Spruce (Picea abies), also known as Norway spruce or European spruce, is a top-of-the-line wood choice for outdoor saunas. This wood is native to Northern, Central and Eastern Europe and is highly sought after for its superior qualities. Its high density and firmly ingrown structure make it extremely durable and perfect for use in saunas. In fact, it is one of the most commonly used woods in traditional Finnish and European saunas. Nordic spruce is also known for its stunning light coloring, which stays mostly white throughout its lifespan. Additionally, this wood has a subtle yet therapeutic aroma that enhances the overall sauna experience. It also contains natural insect-repelling terpenes hydrocarbons, making it an excellent choice for outdoor saunas.

Careful though this is not to be confused with North American spruce which does not container the same properties as Nordic Spruce. Nordic spruce is known for its high density and firmly ingrown structure, which makes it an excellent wood choice for sauna construction. Its density also makes it more resistant to warping and cracking over time, which is important for saunas that are exposed to high levels of heat and humidity.  


  • High density and firmly ingrown structure make it a durable and long-lasting choice for outdoor saunas.
  • Beautiful light coloring that stays mostly white throughout its lifespan.
  • Contains terpenes hydrocarbons which are natural insect repellent.
  • Has a subtle and therapeutic aroma.
  • Has been traditionally used in saunas in Finland and other parts of Europe, indicating its suitability for use in this application.
  • Can be sustainably sourced from forests in Northern, Central, and Eastern Europe.


  • May be more expensive than other types of wood commonly used for saunas.
  • Availability may be limited in certain regions.
  • May require more maintenance than some other types of wood to ensure longevity and durability.
  • May not be as well-known or widely recognized as other sauna woods, which could impact resale value or perception among buyers.

At Backcountry Recreation, we stand by our promise of delivering only the finest quality outdoor saunas that are built to last. We never compromise on the quality of materials we use and only select the highest available wood grades to craft our products. Our commitment to affordable luxury means that we never overprice our saunas, and we strive to offer the best possible pricing every day. While we seldom offer discounts, it's because we already provide unbeatable value for the top-notch products we offer. Now that you have a good understanding of the different wood types, you just need to decide on the heat source - electric or wood-burning. To help with that decision, take a look at our comparison of each below.--
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