7 Reasons Barrel Saunas Fail – What To Look For

Since 2018, we’ve run a free website (SaunaShare.com) for sauna rental companies and mobile saunas. Every week we hear from a new barrel sauna owner who wants to start a business around it.
Over the years, this has become conversation we fear.
We know we will have to tell them why their barrel sauna will fail. We see it over and over again. The barrel shifts, develops cracks, and leaks. Since it doesn’t perform well anymore, it sits neglected and unused for another few years before being given away on Craigslist.
It doesn’t have to be this way.
That’s why were sharing our checklist with you. The things we’ve been telling sauna rental companies for years. With it, you can prevent a bad purchase, build better from scratch, or make the best of the sauna you already have.
Here’s What To Look For, In Order Of Importance
It’s also true that standard barrel saunas don’t evenly heat your body, leaving your feet on the cool floor. #7 solves that but it doesn’t matter how good your sauna performs if it doesn’t last.

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- Roof
- Floor Drain
- Air Vents
- Wood Species
- Screws Not Nails
- Ground Prep
- Upper Benches
#1 All Barrel Saunas Leak (Without a Good Roof)
A barrel sauna is a simple thing. Fitted wooden slats squeezed together around two circular walls. It doesn’t matter how tight it’s squeezed – it will leak water over time. Look for a barrel sauna that includes a roof or plan on adding one.
You can use asphalt shingles, metal, or fitted tarp. We don’t recommend a wood shingle roof. Let’s build something on that will last longer than that.
Good saunas will come with a roof, or at least have it available as an add-on. A company that ignores roofing altogether is a major red flag.
The roof should come down to the widest point of the barrel with an integrated drip edge that ensures the water won’t pool at the base.
This is #1 for a reason. Without a good roof nothing below matters, the sauna will fail.
#2 In Finland, Sauna is a watersport – Where Will It Drain?
So we kept the bulk rainwater out – but you’ll want to pour water on the rocks, wash, or enter dripping wet from the cold plunge. And unless you have a ‘front porch’ model, every barrel sauna leaks through the front door. So you’ll need a floor drain or two.
Most barrel saunas have a drain under the heater, the best have one at the door side as well. These are easy enough to add.
#3 Good Ventilation Makes Everything Better
In addition to drainage, we want the humid air to escape after using the sauna. This is best-achieved with with two vents.
- One air intake vent low on the wall or floor next to the heater. That will bring fresh air into the sauna and ensure the heater can operate properly.
- We also want an adjustable exhaust vent high on the wall. These vents will introduce oxygen, promote air circulation, and dry out the sauna after steamy sessions. Leave this vent open after use.
It’s counterintuitive but these vents also make the sauna hotter by keeping the heaters internal sensor cooler and promoting air movement.
But that’s not all. These vents are also critical to keeping CO2 levels low and oxygen levels high for the bathers.
Like floor drains, these vents are easy enough to add but another red flag if not included or mentioned by the manufacturer.
#4 Wood Species
This one’s interesting and controversial. Until recently, Western Red Cedar (WRC) has been the gold standard in barrel saunas in North America. It has a pleasant aroma and is known for resistance to rot and decay. But we started noticing these were the first to fail.
We think we know why.
The main reason we’ve discovered is that Western Red Cedar today is not your grandpas cedar from old-growth forests. Most of these Cedar forests have been clear-cut, and the ‘second-growth’ cedar has full access to sunlight and nutrients. That may sound good but it grows fast and doesn’t develop the properties we expect from cedar.
Fast growth makes the wood softer, and less aromatic which is OK for the interior cladding of sauna walls. But it’s terrible for a barrel sauna that relies on a straight, single layer of wood for the structure.
The other factor causing cedar barrel saunas to fail is the expansion and contraction of the wood leading to gaps, cracks, and shifting.
Standard wood like cedar expands when it gets hot and/or humid and contracts as it cools or dries. It’s hard to imagine worse conditions for expansion and contraction than a sauna in a cold climate.
You may have noticed most barrel sauna doors don’t close right after a couple of years and this is why. But it also degrades performance of the sauna as too much air is escaping through growing cracks. These saunas are working themselves apart with every cycle.
Some barrel sauna owners successfully keep the water out of the sauna but stop using it after a couple of years because it doesn’t get hot or perform well anymore. This is why.
We highly recommend thermally modified wood or ‘Thermowood’ for barrel saunas. Thermal modification is a natural process that puts wood through a vacuum with extreme temperatures and humidity to change it at a cellular level.
It results in a darker wood that resists rot and is almost 100% stable. They’ve been doing it in Europe since the time of the Vikings, and they’ve gotten really good at it. But be careful, outside of Europe it’s not regulated or tested. Anyone can put their wood in the sun for a few days and call it ‘thermally modified’ and unfortunately some Chinese and American companies do.
One final note about the wood:
Anything less that 1.5″ is will warp and fail. The best staves are 1.65″ thick which makes a big difference in durability and provides better insulation.
#5 Screws Not Nails
Some barrel saunas expand and contract so much they require nails. This is a sign they will loosen up after a couple of heat cycles. Look for a sauna kit that provides and recommends screws instead.
You’ll be glad you used screws if you ever need to move it.
#6 Ground Prep
You need a solid base for the cradles without foiliage underneath. Direct sunlight and good airflow under the sauna will help keep everything dry. Make sure water cannot collect or pool up around the cradles.
Even with thermally modified wood and a good roof, you may experience some mold or fungus on the exterior of the sauna if it’s in a damp climate in a shaded location. Same as you might expect on fence pickets.
You’ll want to treat the exterior and/or power wash it regularly.
OK, we know that was a lot but now we have a structure that will last. There’s one last thing you need to know about barrel saunas before buying one.
#7 The Cold Feet Problem
The main criticism of barrel saunas is a fair one. It only has a low bench so your feet are always on the cooler floor. It creates a pretty wide temperature distribution between your head and toes.
There’s a low tech solution called ‘putting your feet on the bench’ or ‘laying down’. If you’re on a budget, that’s a perfectly fine solution.
But for years there have been barrel saunas in Europe with upper bench configurations that allow everyone to sit in better, more even temperatures. We think this makes a big difference, and they’re not available in North America.
What Barrel Sauna Should I Buy?
We’ve been working for years to make good barrel saunas from Europe accessible in North America. All the options below are built to last. Check them out or book a planning session below. We’d love to discuss your project.
Barrel Saunas Guaranteed To Last and Perform
SaunaLife CL5G | Outdoor 4-Person Icon Cube Sauna with Panoramic Window
Enjoy the unsurpassed luxury of the SaunaLife Cube-Series Model CL5G outdoor home sauna kit. Its modern Scandinavian design features a full-glass front that showcases an incredibly spacious interior with room for up to 4 bathers and a height of over 6’2”! Walls thickness (1.7″) is thicker than any barrel sauna on the market for superior insulation, sound isolation, and thermal mass.
SaunaLife CL4G | Outdoor 3-Person Cube Sauna Kit with Panoramic Window
The SaunaLife CL4G is a small affordable sauna that doesn’t compromise on durability and performance. The SaunaLife CL Cube Series is the only line in this price range that includes a shingle asphalt roof, thermally modified wood, an upper bench, ventilation, floor drain, and an LED light kit. This all-weather sauna may have a small footprint but the inside still comfortable seats 3 people and feels expansive thanks to the thoughtful layout and full glass front window. This highly efficient sauna fits just about anywhere inside or out.
SaunaLife CL7G | 6-Person Outdoor Cube Sauna Kit with Panoramic Window
You wanted an affordable sauna with exceptional heat and steam that’s built to last a lifetime. Meet the brand new SaunaLife CL7G.
Enjoy the unsurpassed luxury of the SaunaLife Cube-Series Model CL7G outdoor home sauna kit. Its modern Scandinavian design features a full-glass front that showcases an incredibly spacious interior with room for up to 6 bathers and a height of over 7 feet!
SaunaLife EE6G 4-Person Barrel Sauna with Back Wall Benches
Looking for a high-performing, modern barrel sauna with a massive view? One that was built for comfort, thermal performance, and long-term durability? The SaunaLife EE6G Barrel Sauna Kit delivers.
The EE6G is the less deep little brother to the groundbreaking EE8G – but with the same 91″ diameter, full glass front, and flat-back seating against the back wall. These trusted European layouts get your feet above the cool and avoid any awkward knee-to-knee encounters.
Both models use sustainably sourced Nordic Spruce that’s been naturally thermally modified to outlast cedar. It’s considerably thicker than the industry standard to improve insulation, rigidity, and longevity.
Simply, the SaunaLife EE6G is an epic barrel sauna ideal for backyards, decks, and vacation rentals.
SaunaLife EE8G Upper Bench Barrel Sauna
Experience truly elevated heat and steam with the extra large SaunaLife EE8G barrel sauna kit. Its remarkable 91″ in diameter and included flat floor creates an inspiring space for stretching out or enjoying the views without bumping knees with the person across from you.
Upper benches mean your feet will rise above the cool floor and take comfort in ergonomic clear aspen benches, approximately 20 inches in depth to invite laying down.
Like all SaunaLife barrel saunas, the thermalwood is sourced and milled in Northern Europe with thermally modified Nordic spruce that’s been treated with heat and steam. The result is a beautiful warm tone that lasts longer than cedar without expanding and contracting.
The EE8G comes standard with a full glass front wall, extra thick 1.65″ staves, asphalt shingles, flat floor kit, and an LED light kit. The SaunaLife EE8G may be the best performing, longest lasting, most spacious barrel sauna ever.
SaunaLife Ergo Premium Barrel Sauna Kit
SaunaLife has set a new standard for barrel saunas in North America with the SaunaLife Ergo Series. In stock from Northern Europe, these easy-to-assemble sauna kits are built to last a lifetime with thick thermally modified wood that lasts twice as long as cedar, a shingle roof kit, and clear aspen benches. The Ergo comes in 3 sizes (SaunaLife E6, E7, and E8) with two window options (W = Back Window, G = Glass front wall). For extra wide diameter with upper benches for the best performance, check out the EE6G and EE8G.
Currently shipping with LED Light Bar.
Thermory Ignite Black Barrel Sauna
$7,170.00 – $9,000.00Good luck looking away from these showstoppers. Thermory Ignite skillfully emulates the burnt aesthetic of shou sugi ban, yet delivers the resilience and constancy only achievable through natural thermal modification. The resulting blend of old-world tradition and modern appeal could last for decades.
Based on our best-selling Thermory Barrel Saunas.
Sauna Squares by Thermory
Where expansive views and rolling steam come easy! The Thermory Square is the ideal sauna for hosting friends, stretching out, or laying down. The L-Bench comfortably seats six, all on the upper benches where optimal heat and steam envelop the bather, guided by the curved contours. It’s remarkably sturdy, and assembly is a breeze. How do we know? Our founder still has the first Square #40 that came over from Europe. Book a free consultation below and we’ll walk you through it.
Thermory Barrel Sauna Kit | 60 Series with Optional Porch and Panoramic Window
Experience the barrel sauna that changed everything. Crafted from the world’s best thermally modified Nordic spruce for unmatched durability and moisture resistance, these saunas feature a curved design for efficient heat circulation, ensuring continuous warmth with less energy. Designed for easy assembly, they come with pre-cut and pre-milled components, allowing quick setup. Available in various configurations, including options with windows and porches, each model provides a spacious and comfortable environment for relaxation and socialization, free from technological distractions.