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.

1. 1. Roof
   2. Floor Drain
   3. Air Vents
   4. Wood Species
   5. Screws Not Nails
   6. Ground Prep
   7. 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.

1. 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.
2. 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.
3.  

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.