Outdoor saunas live in rain, snow, and sun, so buyers naturally look for the sturdiest build. Wall thickness is one of the few construction numbers manufacturers publish, and it’s easy to assume thicker is always better.
This article looks only at what wall thickness does and doesn’t change. Wood species is a separate question with its own answer. For the full buying process, start with the home sauna buying guide.
Short answer: thicker solid-wood walls add stiffness and hold heat better, but they don’t stop rot on their own. Treat thickness as one sign of build quality, not the deciding factor.
Thickness in current outdoor cabins
| Cabin | Wall | Wood |
|---|---|---|
| Almost Heaven Salem (barrel) | 1⅜ in. | North American cedar, ball-and-socket staves |
| SaunaLife G2 (cabin) | 1.65 in. | Nordic Spruce |
| SaunaLife G4 (cabin) | 1.75 in. | Thermally modified Nordic Spruce |
From manufacturer and dealer listings, checked October 1, 2026.
What thicker walls give you
You get more stiffness. Thicker staves and boards resist warping and hold their shape as the wood swells and dries through the seasons.
You get more heat retention. Solid wood is a modest insulator, so a thicker wall holds warmth a bit longer once the cabin is hot, which helps on cold days.
What thickness doesn’t fix
It doesn’t stop decay. Rot depends on moisture and on the wood species or treatment. A thick wall of a decay-prone wood still needs a good roof, a raised base, and maintenance.
It doesn’t set heat-up time by itself. That depends mostly on heater size relative to room volume, plus glass area and air leaks. Heater sizing guides recommend upsizing 25–50% for outdoor and barrel saunas for exactly that reason (2026 sizing guide).
How to judge an outdoor build
Here’s what the spec sheet won’t tell you directly: thickness is a clue, not a verdict. Look at it together with the wood species, the roof (shingles or a membrane), whether the base lifts the sauna off the ground, and the warranty length. The SaunaLife G2, for example, pairs its 1.65-inch walls with a limited lifetime warranty for the original buyer.
More thicknesses from our catalog
| Sauna | Wall | Wood |
|---|---|---|
| Almost Heaven Grandview (barrel) | 1⅜ in. | North American cedar |
| SaunaLife Ergo E7 (barrel) | 1.65 in. | Thermo-Spruce |
| SaunaLife Model X7 (indoor cabin) | 1½ in. | Nordic Spruce |
| Almost Heaven Sutton (indoor cabin) | 1⅜ in. finished | Tongue-and-groove |
From manufacturer and dealer listings, checked September–October 2026.
Indoor cabins use walls about as thick as outdoor ones. So thickness isn’t only about weather. It is how solid-wood saunas are built.
Run the numbers
In millimeters, 1⅜ inches is about 35mm, 1.65 inches is about 42mm, and 1.75 inches is about 44mm. The thickest wall here is about 27% thicker than the thinnest. That is a visible difference in a stave, and a modest one in insulation terms. It won’t turn a slow-heating sauna into a fast one.
Several listings don’t publish wall thickness at all, including the Dundalk barrels and the Redwood Outdoors barrel in our data. Ask for it.
Warranty as a cross-check
If thicker walls meant a longer life, you’d expect warranties to follow thickness. They don’t.
- Almost Heaven’s 1⅜-inch barrels carry a limited lifetime warranty on the cabin.
- SaunaLife’s 1.65-inch Ergo E7 has a limited lifetime residential warranty that excludes normal wear and weathering.
- Redwood Outdoors lists 1 year on the structure of its barrel.
- Dundalk lists 3 years, parts only, on its barrels.
The thinnest walls in the first table have one of the longest warranties. Read the exclusions as well as the length: “weathering” is most of what happens to an outdoor sauna.
Thickness you can check on delivery
When the sauna arrives, measure a stave or wall board with a tape before you assemble it. It takes a minute, and it is the one construction claim on the listing you can verify yourself.
For how these builds compare on price and wiring, see the traditional sauna buying guide.
Bottom line: a thicker wall is a good sign, but the wood it’s made of and how you keep it dry decide how long it lasts.
Sources
- The Sauna Republic, “What Size Sauna Heater Do I Need?” 2026: thesaunarepublic.com
- Wall thickness, wood, and warranty: Almost Heaven and SaunaLife listings via Select Saunas, checked October 1, 2026
- Wall thickness and warranty terms: Almost Heaven, SaunaLife, Redwood Outdoors, and Dundalk Leisurecraft listings, checked September–October 2026