The wood is the part of a sauna you see and touch, so it gets most of the attention. It deserves some. But the most useful thing a builder can tell you about sauna wood is that the species matters less than how well the room is built and ventilated around it. A well-ventilated hemlock sauna will outlast a poorly built cedar one every time. With that said, the wood you choose shapes the scent, the look, the feel against your skin, and the budget, so here is how the real options compare.
What every good sauna wood has in common
Before the differences, the rules. Sauna wood needs to be low in resin and oils, stay cool to the touch at high heat, and resist warping through thousands of heat-and-moisture cycles. That is why you see the same short list of species again and again, and why pine and fir are generally avoided: their resin can weep sticky sap when heated and even cause burns on a bench. Sauna wood is also left untreated on interior surfaces. Stains and varnishes crack under heat, trap bacteria, and can off-gas. The wood is meant to breathe.
Cedar: the premium standard
Western Red Cedar is the most popular choice for a reason. It has natural oils that resist moisture, mildew, and insects, a distinctive warm aroma many people associate with the sauna experience, and a rich color that reads as premium. It is forgiving in humid conditions and ages beautifully. The trade-offs: it costs more, and that signature scent is exactly what some people want to avoid. If you love the smell of a cedar sauna, this is your wood.
Hemlock: the clean, neutral workhorse
Canadian hemlock is the practical favorite, especially for infrared and for larger builds. It performs well across nearly every metric that matters, with low resin and good thermal comfort, and it typically costs 20 to 40 percent less than cedar. It is nearly odorless, which is a genuine selling point for anyone sensitive to scent or who simply prefers a neutral room. It develops a soft silver patina over time. Its one weak spot is that it lacks cedar’s natural oils, so it relies more on good ventilation and routine drying. In a properly built sauna with real airflow, that is a non-issue.
Thermally modified wood: the stability play
Thermal modification bakes the wood at high heat to drive out moisture and resin, and the result is impressive on paper and in practice. Thermally modified hemlock can be roughly twice as hard as cedar and significantly more dimensionally stable, moving about 25 percent less than comparable cedar through heat cycles. For barrel saunas and outdoor builds, that stability keeps joints tight and weather-tight, which is why European outdoor sauna makers have largely moved to thermally modified species. It also tends to be low-scent and very low in allergens. If your sauna lives outdoors or you want maximum longevity with minimal movement, this is the category to look at.
Aspen and basswood: the gentle, allergen-free option
Worth knowing for benches specifically. Aspen and basswood are nearly odorless, extremely low in resin, sand to a fine splinter-free finish, and stay cool against skin. They are the go-to for anyone with respiratory sensitivity or for a children’s or family sauna. Their limit is durability: neither is as naturally rot-resistant as cedar, so they want good ventilation and are best indoors.
The builder’s move: mix them
Here is the thing few people are told. You do not have to pick one wood for the whole room, and often you should not. A common, smart approach is to use a more affordable wood like hemlock for the walls and ceiling, where you need a lot of square footage, and invest in a premium or skin-friendly wood like cedar or aspen for the benches, where your body is in constant contact. The one rule when mixing: choose woods with similar thermal and moisture behavior so they expand and contract at compatible rates. Done right, you get the look and feel you want where it counts and a sensible budget everywhere else.
How we help clients choose
When we plan a sauna, wood is a conversation about three things: the scent you want or want to avoid, where the sauna lives (indoor versus outdoor changes the answer toward thermally modified), and the budget, including where it makes sense to spend and where to save. There is no single best wood. There is the right combination for your room, and we settle that with you up front.
There’s no single best wood, only the right combination for your room. Tell us the scent you want, where the sauna will live, and your budget, and we’ll spec the rest.
Next step
Start with a conversation.
Tell us about your space and you'll get a clear, honest read on the work, electrical included.