Why We Build with Cedar? And the Common Question of Cedar vs Hemlock for Saunas.
We have been building saunas that our customers love and get hooked to once they try it. Be it an authentic Finnish sauna built with authentic Finnish design principles (Reference: Trumpkin’s Notes) or an infrared therapy one, indoor or outdoor, residential or commercial, we truly focus on the most minute details so our customers literally have to turn on the sauna and just relax.
As a sauna manufacturer, we know that customers are confused over one question constantly: “Why cedar? Why not other woods?”
Here’s our no-fluff answer, written for people actively comparing builds.
What we want from sauna wood (everything that shows up in your sauna after 100 sessions):
A sauna is basically a wood stress-test: heat + humidity + expansion & contraction + warping + sweat + time.
So for walls/ceilings and especially benches/backrests, we care about:
- Moisture & decay resistance (mold/rot is the sauna longevity enemy)
- Dimensional stability (less warping, gapping, twisting over heat cycles)
- Low resin / low sap (no sticky pitch when things get hot)
- Comfort in high heat (benches that feel warm, not punishing)
- Renewability (can you refresh it years later, or is it a “throw it out and replace it” situation?)
Why cedar checks most boxes
Cedar is naturally suited to humid, hot environments
Cedar has natural compounds that help it resist moisture-related issues over time. In a room that swings between dry heat and steam, that “built-in durability” matters. Yes, cedar can also sometimes be prone to mold and bacteria, but that depends on the quality of the wood itself and whether the sauna has been maintained the way it's supposed to be. And in terms of the least maintenance required, Pacific Northwest (Western Red) cedar is the best suited.
Pacific Northwest Seattle has plenty of cedar trees
In Finland, the Finnish build saunas with the wood from the trees that grow around them in nature - Nordic Spruce (the name says it - grows in the Nordic regions), Alder, Pine, etc. The reason the Finnish don't use cedar for saunas is simply because it does not grow there. At Salt & Cedar, we constantly look to get the best quality of Western Red cedar wood that grows all around us and can last for decades only aging beautifully with time.
It behaves well across thousands of heat cycles
No wood is immune to movement, but cedar generally holds its shape well when it’s properly dried, constructed, and installed. Over the long run, stability is a huge part of whether a sauna keeps feeling tight and solid and cedar is a great choice in this aspect because it experiences less expansion and contraction in response to changes in moisture and temperature compared to many other wood species. This stability helps it resist warping, cracking, and rotting in outdoor or high-humidity. Untreated cedar can naturally last even 30 years outdoors without any chemicals or treatments.
It’s a great “skin-contact” wood
Benches and backrests are where you feel the material most. Cedar tends to stay comfortable even at high sauna temperatures and has a forgiving feel on the skin, which is why it’s been a classic sauna interior choice.
It can be renewed instead of replaced
A well-built cedar interior with thick lumber can often be refreshed years later (with sanding, cleaning, minor refinishing) instead of feeling like a one-and-done purchase.
The aroma is a bonus, not the pitch
Yes, cedar smells like a forest decided to become architecture. But cedar as a scent is highly versatile and blends beautifully with a vast range of other scents from citrus or floral to herbal or woody, if you use essential oils in your sauna experience. However, we do not choose cedar for the fragrance, we choose it for the performance and the scent is just a side benefit.
Cedar vs Hemlock(the common question)
Hemlock is popular, especially in infrared saunas, because it’s often:
- smoother, lighter-looking, and more uniform
- more neutral in aroma
- commonly used in mass-produced panels in factories because it's less expensive
Hemlock can be a totally reasonable choice for infrared saunas. But where cedar often wins is:
- moisture tolerance over time
- comfort for benches/backrests
- overall stability and durability in environments where people will steam, sweat, and repeat like authentic Finnish saunas
If you’re allergic to cedar or have absolutely zero-tolerance for scent, hemlock can be appealing. If you’re optimizing for the long haul (especially outdoors), cedar becomes a strong contender.
The part most people miss: Wood is only half the story
We’ve seen even luxury or expensive saunas built with premium wood underperform because the fundamentals of sauna design weren’t respected:
ventilation (air supply and flow - mechanical, gravity based, active is make-or-break)
heat distribution (placement, reflectivity, interior geometry)
bench height/ergonomics (how the heat stratifies and where you sit can all decide efficiency or a poor performance with hot/cold spots, cold feet in the sauna)
materials inside the sauna (glues, plastics, chemical smells, VOCs)
outdoor weatherproofing (roofing, base, drainage)
Have more questions? Email us at sales@saltandcedarsauna.com or call us at +1(425) 472-7061 to make an appointment to visit our workshop and learn more about how we build beautiful saunas that feel like you.