Western red cedar is often considered one of the best all-around woods for a sauna, but it isn’t the only good choice. Hemlock, aspen, alder, spruce, and other woods can also work well depending on whether you’re prioritizing durability, appearance, aroma, bench comfort, cost, or resistance to moisture.
Wood is one of the most important materials in a sauna because it affects much more than appearance. The wood you choose will be exposed to repeated cycles of high heat, moisture, and drying. It may also come into direct contact with your skin, particularly on benches and backrests.
For an outdoor sauna, the choice becomes even more important because the exterior must also deal with Minnesota’s changing weather conditions. So, what is the best wood for a sauna? The answer depends on where the wood will be used and what you want from your sauna. Here’s how the most common options compare.
What Makes a Good Sauna Wood?
Not every type of lumber is suitable for use inside a sauna. The environment is considerably different from a typical room in a home.
When comparing sauna woods, consider these characteristics:
- Heat tolerance: The wood should remain comfortable and stable when exposed to high temperatures.
- Thermal conductivity: Lower-conductivity woods generally feel more comfortable against bare skin.
- Moisture resistance: Sauna wood repeatedly encounters sweat, steam, condensation, and drying.
- Dimensional stability: Wood that expands and contracts excessively can warp, split, or develop gaps.
- Resin content: Some woods can release sticky sap when exposed to high temperatures.
- Aroma: Some people love the characteristic scent of cedar, while others prefer nearly odorless wood.
- Appearance: Color and grain can dramatically change the look of a sauna.
- Durability: A frequently used sauna benefits from wood that can withstand years of heat and moisture cycles.
- Cost and availability: Some premium sauna woods can be considerably more expensive or difficult to source.
It’s also important to distinguish between interior and exterior wood. A species that works well for sauna benches isn’t necessarily the best choice for the outside of an outdoor sauna.
Best Sauna Woods at a Glance
| Wood | Best For | Main Advantages | Potential Drawbacks |
| Western Red Cedar | All-around sauna use | Durable, attractive, naturally moisture resistant, distinctive aroma | More expensive; scent isn’t for everyone |
| Hemlock | Affordable interiors | Clean appearance, mild scent, good stability | Less naturally decay-resistant than cedar |
| Aspen | Benches and backrests | Light, low-resin, comfortable against skin | Less resistant to moisture and decay |
| Alder | Traditional-looking interiors | Warm color, smooth appearance, low-resin | Less commonly available in some areas |
| Spruce | Budget-friendly builds | Affordable, light-colored, traditional in Nordic saunas | Can contain more resin and is less decay-resistant |
| Basswood | Benches and interior surfaces | Lightweight, low-resin, comfortable | Softer and less durable for some applications |
| Thermally Modified Wood | Premium builds and exteriors | Improved dimensional stability and moisture resistance | Higher cost |
1. Western Red Cedar: The Classic Choice
If you ask what the best wood for a sauna is, western red cedar will likely be one of the first answers you encounter.
There’s a good reason for its popularity. Western red cedar has a warm reddish-brown appearance, distinctive aroma, and natural resistance to moisture and decay. Its relatively low density also makes it comfortable for sauna interiors compared with many denser woods.
One of cedar’s biggest advantages is its natural durability. Cedar contains extractives that contribute to its resistance to decay, making it particularly useful where wood will experience repeated moisture exposure.
Why choose cedar?
Cedar is a strong choice if you want:
- A traditional sauna appearance
- A distinctive wood aroma
- Good moisture and decay resistance
- Attractive natural grain
- A relatively lightweight wood
- A versatile option for walls, ceilings, and some bench applications
The main disadvantage is price. Clear, high-quality cedar suitable for sauna construction can cost considerably more than alternatives such as hemlock or spruce. Another consideration is the aroma. While many people associate cedar’s scent with the sauna experience, others may prefer a more neutral-smelling wood.
Best for: Homeowners and sauna builders who want a durable, traditional, premium-looking sauna interior.
2. Hemlock: A Practical Alternative to Cedar
Hemlock is one of the most common alternatives to cedar, particularly when cost and a neutral appearance are priorities.
It typically has a lighter color and more subtle grain than cedar. It also has a much milder aroma, which can be an advantage if you don’t want your sauna to have a strong wood scent. Hemlock is commonly used for sauna walls, ceilings, benches, and other interior components. Its relatively consistent appearance can also give a sauna a clean, modern look.
The trade-off is that hemlock doesn’t have the same natural decay resistance as western red cedar. That doesn’t make it unsuitable for sauna use—it simply means that proper construction, ventilation, and moisture management are particularly important.
Why choose hemlock?
Hemlock may be a good choice if you want:
- A lighter-colored interior
- Minimal wood aroma
- A clean, understated appearance
- Good performance without paying cedar prices
- A readily available sauna wood
Best for: People who want a practical, attractive alternative to cedar without a strong wood scent.
3. Aspen: Excellent for Sauna Benches
Aspen is particularly popular for sauna benches and backrests. One reason is comfort. Aspen is a relatively lightweight, low-density wood, which means it doesn’t conduct and retain heat in the same way as many denser woods.
It also has a very light, clean appearance and little natural aroma. For someone who doesn’t want the strong scent associated with cedar, this can be a significant advantage.
Another benefit is its low resin content, making it suitable for surfaces that come into direct contact with bare skin.
The biggest downside is durability. Aspen isn’t naturally as resistant to decay as cedar, so moisture management and ventilation are especially important.
Why choose aspen?
Aspen is a good option if you want:
- Comfortable sauna benches
- A light-colored interior
- Minimal aroma
- Low-resin wood
- A clean, Scandinavian-style appearance
You don’t necessarily have to build the entire sauna from one species, either. For example, a builder might use cedar for the walls and aspen for the benches. Mixing species allows you to take advantage of the strengths of each.
Best for: Benches, backrests, and people who prefer a light-colored, low-aroma sauna interior.
4. Alder: Warm, Smooth, and Traditional
Alder is another wood commonly used in sauna construction, particularly in Scandinavian and Baltic sauna traditions.
It has a warm appearance that falls somewhere between the very pale look of aspen and the reddish tones of cedar. Its relatively uniform grain gives it a smooth, refined appearance.
Alder also has little resin, making it suitable for interior sauna applications.
Its main disadvantage for some homeowners is availability. Depending on where you live, finding high-quality, sauna-grade alder may require ordering from a specialty supplier.
Why choose alder?
Alder can be a good choice if you want:
- A warm, natural color
- A relatively subtle grain
- A mild aroma
- Low-resin wood
- A distinctive alternative to cedar or hemlock
Best for: Sauna interiors where appearance and a warm, natural aesthetic are priorities.
5. Spruce: A Traditional Nordic Option
Spruce may seem like an unexpected choice to North American homeowners, but it has a long history in Nordic sauna construction. It’s relatively affordable, lightweight, and has a pale appearance that works well in traditional Scandinavian-style saunas.
Spruce can be an economical option for walls and ceilings, particularly for sauna kits and other budget-conscious projects. However, spruce can contain resin or knots that may become problematic when exposed to high heat. For that reason, the grade and selection of the lumber matter, especially for benches and other surfaces where people will sit or lean.
Why choose spruce?
Spruce may make sense if you want:
- A traditional Nordic appearance
- A light-colored interior
- An affordable material
- A readily available softwood
Best for: Budget-conscious builds and traditional Nordic-style sauna interiors, particularly when appropriate sauna-grade lumber is selected.
6. Basswood: A Comfortable Bench Material
Basswood is another option worth considering, particularly for sauna benches and other surfaces that come into direct contact with the body. It’s lightweight and relatively soft, with a subtle appearance and little natural aroma. These characteristics can make it comfortable for seating and backrests.
Its softness is also a limitation. Basswood can be more susceptible to dents and surface damage than harder woods. For that reason, it’s generally more appropriate for specific interior applications rather than necessarily being the best choice for every part of an outdoor sauna.
Best for: Benches, backrests, and users looking for a light, neutral wood with minimal aroma.
7. Thermally Modified Wood: A Modern Option
Thermally modified wood has become increasingly popular for outdoor construction. The wood is exposed to controlled heat during manufacturing, changing some of its physical properties. Thermal modification can improve dimensional stability and resistance to moisture-related movement and decay.
This makes thermally modified wood particularly interesting for outdoor sauna exteriors, where the wood has to withstand rain, snow, humidity, sunlight, and temperature changes.
It’s also available in different species, so “thermally modified wood” isn’t a single type of lumber.
The primary disadvantage is cost. It’s generally more expensive than conventional options.
Best for: Premium outdoor sauna exteriors and projects where weather resistance and dimensional stability are priorities.
Does the Best Wood Depend on Where You Use It?
Absolutely. One of the most important considerations when choosing sauna wood is where that wood will be installed. The walls and ceiling have different requirements from the benches. The exterior has completely different requirements from the interior.
Sauna walls and ceiling
For walls and ceilings, common options include:
- Western red cedar
- Hemlock
- Aspen
- Alder
- Spruce
- Thermally modified wood
Because these surfaces aren’t constantly in direct contact with bare skin, appearance, durability, aroma, and cost may matter more than how the wood feels to touch.
Sauna benches
Benches deserve special consideration because people sit or lie directly on them.
You generally want wood that:
- Doesn’t become excessively uncomfortable when heated
- Has low resin content
- Is smooth and relatively splinter-free
- Handles repeated moisture exposure
- Can withstand regular use
Aspen, alder, basswood, and carefully selected cedar are common choices.
Sauna exterior
For an outdoor sauna, the exterior has to deal with the weather. This is particularly important in Minnesota, where an outdoor sauna can experience freezing temperatures, snow, rain, humidity, and significant seasonal changes.
Cedar and thermally modified wood can be attractive exterior choices because of their resistance to outdoor conditions. However, the roof, drainage, ventilation, flashing, and installation details are just as important as the species of wood.
A naturally durable wood can still deteriorate prematurely if water is allowed to remain trapped against it.
What Wood Is Best for a Minnesota Outdoor Sauna?
Minnesota presents a unique environment for an outdoor sauna. A sauna might be exposed to hot summer conditions, heavy snowfall, freezing temperatures, spring moisture, and repeated freeze-thaw cycles.
For the exterior, western red cedar is a popular choice because of its natural resistance to decay and its ability to handle outdoor exposure when properly installed and maintained.
Thermally modified wood is another option for homeowners looking for enhanced dimensional stability and a modern appearance.
For the interior, the Minnesota climate matters less because the interior should be protected from direct weather. Here, the choice can come down to comfort, appearance, aroma, durability, and budget. That means you could have a cedar exterior with an aspen or hemlock interior, for example.
Should the Whole Sauna Use the Same Wood?
No. Using the same species throughout is certainly an option, but it’s not a requirement.
A mixed-wood sauna can actually be a practical solution.
For example:
| Sauna Area | Possible Wood Choices |
| Exterior siding | Cedar or thermally modified wood |
| Interior walls | Cedar, hemlock, spruce, or alder |
| Ceiling | Cedar, hemlock, spruce, or alder |
| Benches | Aspen, alder, basswood, or clear cedar |
| Backrests | Aspen, alder, basswood, or cedar |
| Trim | Matching interior wood |
Using different woods can also create visual contrast. A darker cedar wall combined with pale aspen benches, for example, can create a clean and inviting appearance.
What Wood Should You Avoid in a Sauna?
Choosing the right wood isn’t just about finding a species that works. It’s also about selecting the right grade and lumber for the application.
Some common construction lumber may not be appropriate for sauna interiors, particularly areas that experience the highest temperatures or direct skin contact.
Be cautious with resinous woods
Some pine and spruce products can contain significant amounts of resin. When exposed to high temperatures, resin can soften or bleed from knots.
That doesn’t mean every pine or spruce product is automatically unsuitable for a sauna. Nordic saunas have traditionally used spruce, for example. The important factor is using appropriate, properly selected sauna-grade material rather than assuming any board from a lumberyard will work.
Avoid treated lumber inside the sauna
Pressure-treated lumber and other chemically treated construction materials should not be used as exposed interior sauna surfaces. Sauna interiors operate at high temperatures, so material selection should follow the specifications of the sauna manufacturer and heater system.
Don’t choose wood based only on appearance
A beautiful board isn’t necessarily a good sauna board.
Look at the species, grade, moisture condition, knots, intended application, and manufacturer recommendations before making a decision.
Does Sauna Wood Need to Be Sealed?
Interior sauna wood is generally treated differently from ordinary household woodwork. Because the sauna repeatedly heats and cools, the interior should be able to handle changes in moisture and temperature appropriately. Applying an inappropriate finish can change the way the wood behaves and may create unwanted odors when heated.
Some sauna-specific products can be used on benches or other surfaces, but you should always follow the recommendations of the sauna manufacturer and the finish manufacturer.
Outdoor wood is different.
Exterior siding may benefit from an appropriate exterior finish or UV-protective treatment depending on the species, desired appearance, and exposure.
In other words, don’t treat the inside and outside of an outdoor sauna as if they’re the same environment.
Cedar vs. Hemlock vs. Aspen: Which One Should You Choose?
If you’re deciding between the three most commonly discussed options, here’s a simple way to think about them:
Choose cedar if:
- You want the classic sauna experience
- You enjoy a natural wood aroma
- Durability is a priority
- You like a warm, reddish appearance
- You’re willing to spend more
Choose hemlock if:
- You want a clean, light appearance
- You prefer little or no wood aroma
- You want a practical alternative to cedar
- Keeping costs reasonable matters
Choose aspen if:
- Bench comfort is a priority
- You want a pale interior
- You prefer very little aroma
- You’re interested in a traditional Scandinavian look
- You’re willing to pay more attention to moisture management
There isn’t a universal winner. The “best” option depends on what matters most to you.
What Is the Best Wood for Sauna Benches?
For benches specifically, aspen, alder, basswood, and carefully selected cedar are among the options worth considering.
The most important qualities are comfort, low resin content, smoothness, and durability. Because benches come into direct contact with skin, you generally want to avoid wood that becomes excessively hot or has significant amounts of resin that could bleed when heated.
This is also one reason that choosing the cheapest available construction lumber isn’t necessarily a good strategy for sauna benches.
What Is the Best Wood for a Sauna?
For many homeowners, western red cedar is the best all-around sauna wood because it combines durability, appearance, moisture resistance, and a traditional sauna aroma.
But that doesn’t make cedar the right answer for every sauna.
Hemlock is a strong alternative for a clean, neutral-looking interior. Aspen is particularly appealing for benches and people who prefer a light, low-aroma wood. Alder offers a warm, distinctive appearance, while spruce can be a cost-effective choice when properly selected for sauna use. For outdoor applications, thermally modified wood can provide another option where weather resistance and dimensional stability are priorities.
Ultimately, the best sauna isn’t necessarily the one made entirely from the most expensive wood. Proper ventilation, construction, moisture management, insulation, heater selection, and maintenance all have a major impact on how well the sauna performs.
For an outdoor sauna in Minnesota, think about the project as a whole: choose durable materials for the exterior, comfortable wood for the interior, and construction methods that allow the sauna to dry properly after use. That approach will matter far more over the long term than simply choosing the most expensive species available.
