I always loved physics because it deals with the tangible effects of the forces of nature— the interactions between matter and energy—that explain the things that we feel or see on a daily basis. Specifically, I want to delve into the transfer of heat, which seems to be a hot topic in sauna forums.
There are three methods of heat transfer: conduction, convection, and radiation. In a sauna, (and everywhere else, unless you live on a planet at absolute zero: -460 °F) there are all three. Heat always goes from a warmer object to a cooler one, and a closed system is entropic, that is to say, if you sip too slowly, the ice will melt and your drink will eventually all be the same lukewarm room temperature. The transfer of heat is greater when the temperature difference (ΔT) is greater, and it slows over time, until the temperature equalizes in a system, which, for our study, includes not just inside the sauna, but the environment it sits in. Which is to say, no matter how well you insulate it, eventually the sauna will reach the ambient outdoor temp, unless, like a house (or a sauna in a house,) you keep the heat on. This is a factor in freestanding sauna design as we have to assume the starting point is anywhere from 0 to 100°F (unless it is fired up constantly) and the desired bathing temp is 180-220°F. In a house we are trying to hold the temp at about 70°, in the residential sauna, we need it to hold temp for a few hours, at the most.
Conduction is the transfer of heat from one solid or liquid to another by direct contact. You Grab a (foolishly installed) metal doorknob to the sauna that is either 200°F or 10°F, depending on the season, and which way you are going, and the heat rapidly conducts either to your hand or from it, with a resulting shriek. Same is true if someone pushes you against the hot stove as you try to leave the sauna, burning your butt to the point where sitting was impossible for two weeks, as happened to me once. This is conduction which we typically try to avoid in the sauna, but it happens. Less dense materials, like your towel, mitigate conduction, which is why we look for low density boards like cedar, not hardwood, for the benches, which would feel like a hot iron on your posterior.
Convection is the transfer of heat through the movement of fluids. It is in part driven by gravitational forces whereby warmer gasses or liquids are typically less dense and lighter and thus tend to rise as cooler ones sink. This create a convective loop as the heat is circulated to, say, the walls of the room, or you on the top bench, and then the air cools and falls, creating an endless loop. I say typically, because there is this oddball exception: water close to freezing gets less dense and thus freezes on the top of lake or pond, making hockey, ice plunging after a sauna round, and life on this planet, possible. If the movement of air is stopped, say by the fibers of mineral wool or two close layers of glass, it becomes an insulator. Air itself holds very little heat per volume-more than a thousand time less than water, whereas water holds twice the heat energy of granite and about the same as steel. A large volume of this dense, heat holding material is called a thermal mass, which can mitigate the fickle effects of convection, especially when the air is coming and going, by acting as reservoir of heat. That is why we try to keep the door closed in the sauna—all of the air convecting nice warmth around us is disturbed by the cold air rushing in to take it’s place. But that’s not so bad—as we actually want the fresh air—as long we have some thermal mass to mitigate the swings in temperature.
In home construction, the emphasis is on controlling convection: eliminating it inside wall cavities and not allowing warm air to escape from heated (conditioned) spaces, especially up high where it creates a chimney effect, whereby escaping warm air creates negative pressure and sucks in cold air from wherever it can. In a not-so-old house on a cold night, put your hand over the wall outlets—even on interior walls— and you will likely feel cold air being sucked in. More so if a you have a big cozy, romantic, fireplace with an actual chimney and a roaring fire, which feels great, but sucks the heat right out of house.
In a freestanding wood fired sauna, there will be leaks and cold air coming in. That’s ok because we want fresh air, as long as we control where it comes and goes. Air and steam will move the heat around but eventually it settles into strata: hot up high and cold down low. Air movement can help break up this layering of cold to hot, but it is difficult to control. Thus, the upper bench will always be hotter; unless you have an Aufgussmeister to move the heat around with his swirling towel dance.
The last method of heat transfer is Radiation. Sounds bad, like Chernobyl, but radiation is everywhere; all objects with a temperature above absolute zero emit thermal radiation, mostly in the infrared range that we can see with a special camera. At a certain point heat becomes light you can see and the color of the light corresponds exactly to a temperature. The dull red glow of a poker in the fire ( or the top of my sauna stove when I fire it hot) is 1200°F. The surface of the sun burns at 5772°K, which is the color of the sunlight we bask in on the beach. Fortunately, the sun appears relatively small, otherwise we would burn up instantly. We radiate as well; after getting sunburned, your skin will be hotter than the person next to you and will radiate heat to them. In fact all bodies, especially black bodies, which are not necessarily black, radiate and absorb heat, depending on which is hotter. The only things that are not black bodies are things like foil, which reflects most heat directed at it. Surface area and angle of incidence also matter; the more surface area and the more parallel two surfaces are, the more heat transfer. Temperature difference matters too: too much and the effect is intense, like when I pour bronze and have to stand an arms length away from the pot of molten metal, or stand on a subzero surface in winter and feel the heat being sucked from my body. Too little difference in temperature (ΔT), and radiation is hardly noticeable. Direction is also important. The fireplace heats our front but not our back. I have a story about a cold drizzly camping trip where all we could do to stay dry was to keep putting our jackets on backwards then forwards as we sat by the fire. And in all these situations it is aluminum foil that saves the day: as an apron to wear, a foil surface to stand on, or an emergency blanket over the shoulders. Foil blocks radiation, (but it does need an air gap, lest it become extremely conductive); without any barrier, heat, like light, radio waves and the rest of the electromagnetic spectrum can radiate millions of miles. Those episodes of Leave it to Beaver are still traveling through space.
In the sauna, radiation is really important as it creates this enveloping heat coming at us from everything hotter than 98°F. If the whole room- walls, benches and rocks, is 200° or more, we will feel the heat coming from each of those surfaces. Colder surfaces like a big window, or that guy that just got out of the cold plunge, will suck heat from us. Something too hot—like a blasting fire in a single wall stove pipe— will feel searing. In an electric sauna, the rocks need to cover the elements so we don’t see/feel the searing red heat. The much cooler—but still hot–rocks will then reradiate the softer heat. Foil, behind the cedar wall (or other wood), will reflect the heat back towards the cedar which will re-radiate towards the interior. The walls need to be just so hot. Radiation also mitigates the effect of the constantly changing air. The air may be cool, but the radiation of the hot surfaces will cut through the cold like the winter sun on your face. Speaking of, nothing like a full body sun-bath on a calm, freezing day to boost the sauna experience! The thermal mass mentioned above will continue to radiate heat even as the door is left open. Cool air swirling in will kill the radiation buzz for sure, but as soon as the door is closed that warm fuzzy feeling will come back.
So how does all of this daydreaming back to high school physics class inform how I build my saunas? A lot. I want the radiant heat off of the stove to work for me, warming me just so, like the sweet spot in the campfire where you should put your skewered marshmallow (but never do). I aim for a soft radiant heat, like a ΔT of a few hundred degrees at most (me: 98°, the rocks 400°,) but also omni-directional heat (which gets all the walls and benches up to 200° before taking a sauna) and not too intense (make sure the fire has died down and the stove pipe, if single wall, is not too hot). A big window is pretty to look out of, but not too big, as it will suck the heat away from you and a cold cascade of negative convection will sweep over the floor. Thermal mass is great, but not too much, because the sauna will take forever to heat up, and no one seems to have to time for the daylong ritual sauna used to be. I have my bathers all facing the rocks and typically the stove is fired from outside, so there is no worry about the intense (visible) radiant heat through the firebox glass door, which, as cozy as it sounds, may feel too much sitting around a hot campfire and is not the kind of heat you want in a sauna.
Recently I heard, in an online sauna forum, two seasoned sauna veterans saying you don’t want radiant heat in a sauna. I believe they misspoke. You don’t want high intensity radiant heat, but no radiant heat just is not possible, unless everything has reached a state of equilibrium. That is to say, you are as hot as the rocks, thus cooked like a goose (or the sauna is only 100°F). As long as you are cooler than the rocks, stove, walls and benches, heat will radiate to you. It is said that when you close your eyes in a good sauna, you cannot tell where the stove is.
How do we get there? Fire it hot to get the rocks and the whole sauna hot, but let the intense fire die down before getting in. Use radiant foil behind the wood (with an air gap) so the foil can reflect heat back into the wood, use a high rock capacity stove or heater to hold and radiate the heat, and make sure everyone can see the heater so the radiant heat—which travels as waves, like light— reaches everywhere.
You can always tell when there has been a really good sauna; everyone coming out looks so… radiant!
Having grown up around the waters of Cayuga Lake, whose long finger touched the shores of my childhood stomping grounds, it is no wonder that our dreams often turned to things nautical. Since we first started taking saunas at Podunk in our early teens, the fantasy topic of floating saunas always came up. We loved swimming in the lake, but its waters are only warm enough to swim from the beginning of July to about mid- September. What a better way to extend that season than with a sauna? What a better way to sauna than not just near the water, but on the water (oh, but we did enjoy the naked runs to the creek!)
I’ve had an ongoing affair with boats: I have a love of canoes that goes back to my discovery of the Adirondack waterways which form an almost continuous route from civilization into the deep wilderness, and back; the caveat being that short carries were required.
I started making one years ago: a strip canoe affair. Not strip, as in naked, but “strip” as in thin bands of cedar, all joined and sandwiched between two epoxy and fiberglass layers. I never finished that boat; its progress was aborted midstream after I broke my collar bone in three during a trail running race. The unfinished shell still looms over my shop as a reminder, high up in a loft space. So, suffice it to say, that when a client approached me about building a much bigger boat, I had my hesitations about my luck with boats.
Mark initially wanted a beachfront sauna. Then zoning and other issues steered us to thinking of a floating sauna. My childhood fantasy! Granted it is not a new idea; in fact, there are several in Norway and other places. But on Cayuga Lake? This was to be a first. It made sense, in a fantastical way. He had ample dockage, and limited beach; he was willing to invest in the idea and take the risk, and he was a nice guy with just enough chutzpah to make it happen.
Client Mark and Family on Maiden Voyage of Sauna Boat, Cayuga Lake, New York.
The Design phase took over a year. It was a real challenge because this is not just carpentry but nautical engineering; precision was required, and my hand-drawn methodology needed some sharper pencils. Some 30 pages of drawings later and we were ready to build. We had a great fabricator for the frame, ladder-stair, and railing (Service Machine Tool in Elmira, NY) and some other great help along the way, but the whole thing—all 26 feet of it— was assembled in the shop. It was a challenge as the beast took over—floor to ceiling—and there was a lot of self doubt along the way to trip over.
I am not a boat builder so there was as much learning as doing, but we pulled it off—including the challenging work of four round cedar windows trimmed with real ship-salvage portholes.
There were a lot of other finicky details (I have come to understand that boat building is all finicky details). The biggest challenge was loading and transporting it on an oversize low-boy flatbed truck. At one point we had the 10,000-pound hulk levitating on three forklifts as the low-boy flatbed backed under it. The guys at Lansing Harbor Marina gave us confidence, especially after it passed its initial float test. After a few months of tweaking we took the maiden voyage, complete with a champagne toast.
The unique thing with our sauna is that it is a fully navigational boat with twin Electric motors and the sauna is fired with a gas fired heater and has 12-volt electric lights powered by a solar system. Ideally it will be used on a calm day when you can drift out to the middle of the lake, sauna, jump into the clear waters, cool off on the roof deck, and repeat until the fantasy has been satiated. Maybe even under the stars, or Northern Lights.
Thanks to everyone who helped make this possible, Especially Scarlet, who believed in the dream, and Mark and Karie, who supported it.
The old Sauna at Podunk had two rooms: a small dressing room and the larger hot room. The Old Nippa stove sat between them embedded in a masonry wall. Sitting on the benches we stared at the business end of the stove with its pile of rocks and the stove was tended from the dressing room.
This arrangement always made sense to me and is how I have been building my saunas for 30 years. I learned to weld in art school and set up my own studio soon after. Ozzie would send people my way for their stove repairs. After seeing how other stoves failed, I designed and started making my own stoves using much heavier plate on the top, where the heat would soften the thinner steel and typically lead to collapse under the weight of the rocks. I also kept to the external feed (thru-wall) and designed my stoves to be fired exclusively that way. As kids, we loved to pretend we could speak Finnish by stretching vowels and consonants together and making up Finnish sounding nicknames for each other. I called my stove the Lämpimämpi by combining Lemp and Memp. Finns will chuckle at this because it translates to: “warmer”.
I called my stove the Lämpimämpi by combining Lemp and Memp. Finns will chuckle at this because it translates to: “warmer”.
There are so many reasons for the external feed (thru-wall):
• The fire-tending, and ash debris are kept out of the hot room and you don’t have to tramp in and out with your boots on to tend the fire.
• Venting a small space can be complicated; a sauna stove requires significant combustion air which can create drafts or, worse, rob oxygen from the hot room. The external feed draws air from the dressing room or outside.
• Any stove front requires 36 inches of clearance to combustibles in front of it. This can’t be mitigated by heat shields. This severely limits the layout of the hot room. However, it is easy to get 3 feet in front of the stove in the dressing room.
• Any stove also requires a noncombustible hearth (stone) 18” in front of the stove. Hot ash and coals falling out the stove are a major source of fires. In a crowded and dark sauna room these hot coals can easily be overlooked, fall under duck boards, etc.
•A flickering flame to look at may be romantic but it is the soft heat off the rocks you want, not the searing radiant heat you get from sitting in front of a blazing fire. Typically, the fire may be almost out by the time the sauna is ready. The rocks should be the focal point. Also, following the 36-inch rule above, you can’t have the stove front facing the bathers, unless the sauna is excessively big.
• If you are providing a sauna experience for others, you can discreetly tend the fire without interrupting the bathers or invading their privacy.
•The external feed stove heats the dressing room just enough so that you can hang out and watch the fire while the sauna heats up.
Installing the external feed may seem daunting but it is not that difficult. A firewall with the requisite size opening will be required. This can be solid masonry, which will add thermal mass (and take longer to heat the sauna) or a hollow insulated firewall with steel studs and cement board, and tile or stone facing, or stucco over metal lathe (which I typically use). A metal sleeve will be provided with the stove to dress up this opening and provide further heat shielding. My Lämpimämpi stove has an integrated heat shield / rock basket that works with the wall opening so that fresh air coming in is heated directly by the stove and directed over the rocks, which is an advantage over simply having the rocks sit on top inside a steel box. As with any installation, all listed clearances need to be adhered to, but with this method, the stove will take up less space in the hot room and make for a cleaner presentation. For your next sauna, consider this traditional way of building it.
The emergence of Ai generated content has me worried about the future. People live, dream and work in the digital world and increasingly use Ai to create content, which seems to be the end, not the means to something tangible. As someone who has always worked with my hand’s it’s a mystery how something like Facebook gets valued in the Billions of dollars while those of us who actually produce products that are used in the physical realm rack up value only with each object we make.
There is a real disconnect from the process of making; a few computer clicks is all is takes to have a package show up at your door.
As a maker who has to rely on an efficient procurement process to keep my shop stocked, I get the impulse, but I also try to remember that there is always a person on the other end. For example, we buy vitahs that are from Estonia; I envision the worn hands that gather and bind the birch. I appreciate it when materials come with a hand written note of thanks or other human touches. The same search for human connection applies to communication. Each time I get an email inquiry I have my Ai filter humming- is this a real person? With the pandemic of spam and spoofing, I typically won’t even answer the phone unless know the caller and I spend way too much time deleting texts I don’t want. I occasionally scan the web to see what other sauna builders are doing; it means wading through a minefield of Ai generated crap. Not only do many sites not have any identifiable person attached to them but their ”product” is simply stolen images of other people’s work. I recently had to send a cease and desist notice to someone marketing a full array of my saunas as their own. Included were photos I took from inside my shop or in my backyard, complete with my sculptures. If someone is going to be so brazen, why not just steal my humanity and include a photo of me ? This is actually happening with deepfake videos that generate real-seeming talking heads of celebrities and public figures.
The good news is that building a sauna takes actual materials and real hands-on work. I can guarantee that each of the images on my web page are real, that the photos were taken by us in locations we were actually at and that they show just a sampling of the 150 or so saunas I have built.
The splinters I pull out of my hands on a near daily basis are real as well.
We are a family run business— basically just the two of us; there are no pushy sales reps or people working phones off site (as in another country). If we do answer your call it is only because the saws stopped running long enough for us to hear it ringing (which why we prefer email) and even though it may take a few days to get back to you, I guarantee it will be a real conversation. Hopefully, one that one leads to face to face meeting and enduring relationship. Saunas, after all, are all about human connections.
As you scan the web on a weekend morning, looking for that perfect sauna experience, be aware that only thing real thing may the aroma of the freshly brewed cup of coffee in your hand. If you don’t yet have your own sauna, find a friend who does or one of the many public saunas that are sprouting up, and immerse yourself in the physical realm, sans digital devices. Thankfully, Ai will never have anything to do with enjoying the blissful bodily experience of taking a real sauna!
One the endearing features of our saunas that falls under the rustic elegant motif that we employ is the use of stick hardware. These also fall under the category of Finnish Pragmatism that is an influence in my design; whereas superfluous embellishment is avoided and using what is at hand is always desired over spending for what you don’t really need. In my head I keep an inventory of all the random parts I have collected over the years that are stowed away in my shop and when a need arises I quickly do a mental scan and see if something in stock will do rather than going to a hardware store or jumping online. Likewise, I often resort to “natures hardware store” when I need things like door pulls and towel hooks.
It is amazing all the parts you can extricate from the intricate workings of tree.
The best is Hickory because of the way branches crook when they take off in a new direction, and it is very hard. After all, they make baseball bats out it. Recently we had to fell a Hickory so I salvaged all the door pulls and towel hooks I could from it.
wood-fired outdoor sauna
The tree will live on as it greets sauna users with a sturdy handshake each time they enter the sauna.
It’s the small personal touches and attention to detail that makes us proud of our work and makes our work fun and enjoyable. By avoiding the cold and the common place, we make each sauna as unique as its owners.
The latest sauna that we built is an indoor electric affair in a new addition that also holds a hot tub and pool, an enviable personal home spa combination. It has an ample window and large 10 kw Harvia Cilindro heater that should make the top bench a real hot spot. A feature of this sauna that I love is the view from that bench. Not just any view, but one that takes me back to my childhood.
The property is located on the eastern shoulder of Cayuga Lake, at a point where the land starts to dip dramatically downward to the long snaking shore. The slope is so steep here, that you don’t see the lake, only the opposite side, a little more than two miles away. Someone unfamiliar with our landscape might not even be aware that the longest of the Finger Lakes fills the glacial trough below. While the scene feels close, it is, in fact, a long journey away.
Most pronounced is Rice Hill: the old ski and sledding hill that, at one time had a rope tow run off of an old tractor motor. At the top of the hill is a warming hut and two shallow ice rinks, where many a hockey game was played. When we were too broke or didn’t have the ambition or means to go to the closest downhill ski area, we would go to Rice Hill and practice our ess turns. I also recall many tobogganing adventures; it was the kind of hill where serious injuries where the mark of a good run.
Just to the north was a ten-acre parcel my parents bought in the 1960’s with the dream of building a house. My dad designed it with all the meticulous detail he employed on his larger architectural projects. It was a three story modernist affair, with a flat roof, and cantilevered balconies that would have commanded a view across the lake to precisely where this sauna is.
In the early 70’s, things turned south for my Dad; there was a recession, he lost his job, increased his drinking, and the dream of the modernist masterpiece overlooking the lake was deflated like a balloon the cat played with. All we were left with was the model of the house my dad crafted out of mat board, with twigs as stand-ins for trees. Later, before my parents had to sell the property as a part a bankruptcy plan, I actually lived there in my tent after I finished Grad school and waited for my dreams to come to life.
I bring all of this up become of the associations of sauna with memory. So many of my clients, who are typically, like myself, aging baby boomers, tell me that they want a sauna because of the wonderful childhood memories they have of taking saunas. Perhaps their family has Finnish roots and they experienced summers in Finland, or they had a camp somewhere with a sauna. Like my experiences at Podunk, these childhood memories start to loom larger with age. Memory acts as a filter; the important things are retained and the trivial is set aside.
Landscape acts as a placeholder for memory. Living where I grew up, I constantly encounter places that stir memory. Working with my past literally out the window on this job, I was constantly reminded of my connection to this magical place in the heart of the Finger Lakes. Sauna is like a keystone in all of this.
Like so many saunas that I build, I dream for a moment; what if it was mine? But then, I hand over the sauna to the new owners so they can ponder their own dreams. In this case, the owner will be looking at the near view of the land he grew up on.
I have always been fascinated by fire. There is a mystery to it that even science cannot unravel. It is more like the fourth state of matter—plasma—than the familiar trio of liquid, gas and solid. I have played with and studied fire since I was a kid, sometimes barely avoiding serious trouble, other times under the guidance of elders, like in Boy Scouts where we boiled a quart of water in five minutes during fire-building competitions. As I grew older, burning wood became a way to heat our home. Wood cutting and splitting became not only a chore but a workout and a way to get my angst out with each strike of the axe.
After I learned metalworking in art school, I started to apply my skills to making wood stoves and thinking about what happens inside of a stove- the mysterious process where tons of wood are reduced to a small amount of ash, carbon dioxide, particulate, and other emissions that are carried away by the wind. The heat is from the atomic bonds of carbon molecules breaking, turning matter back into the energy of the sun that formed those molecules. There is something seductively simple in that balance of carbon in/carbon out, but, as we now know, there is also something deviously complicated about the carbon cycle. I have warmed myself with wood heat over the years in my home, shop, and sauna; each time I light a fire there is still this fascination and allure to the flames that draws me to it and perhaps blinds me to greater issues.
In the past 50 years, wood stoves have gone through several changes. Initially they were simply boxes with a loose-fitting door and a chimney—like the Ben Franklin stove. These stoves burned uncontrollably and inefficiently and needed constant feeding. Later, air-tightness became a thing: dampers were dialed in, rope caulk was added to the doors, and the fires were slowed down so they could burn all night. But as the fire burner longer and cooler, not all the organic matter was burned— more went up the chimney. Flammable wood gasses called creosote condensed on the cool sides of the chimney, building up thick tar-like layers. Eventually that caught on fire, sometimes taking the whole house with it. In the 70’s we went though the energy crises and wood stoves became a very popular way to deal with spiraling oil cost. The 70’s also saw the birth of the environmental movement and the EPA. The EPA stepped in as did Underwriter’s Laboratory (UL). Stoves had to be made safer and cleaner burning. Expensive Catalytic convertors—like on your car—were added to the stove outlet, to capture some of the nasty stuff. But neophytes, in their craze to burn wood, skipped the all-important step of letting firewood dry at least 2 years. The converters clogged up. The cats were dropped, and the focus turned to better engineering. Stoves are now designed with all kinds of baffles to get the wood to burn cleanly; they are complicated affairs, and many don’t work that great- they certainly don’t burn all night, or, as I used to do with mine, burn non-stop, all winter.
But sauna stoves are a different beast. Since they are “occasional use only” (and only one is UL listed) they are, thankfully, technically EPA exempt. But still, I don’t want to be “that guy” that smokes out the neighborhood every time I light my sauna—especially since this past summer when we all got a taste of the Smoke Armageddon. So, despite my years of wood-burning experience, I am always trying to tweak the process and learn the idiosyncrasies of my stove. Every stove fires differently and even a familiar stove can rebel on you when the wind changes or you when move the sauna. When I light mine, I know it will smoke some; my goal is always to get it burning hot as fast as possible so the smoke will be minimal.
The three sides of the fire triangle are heat, fuel, and oxygen. A perfect balance gives a cleaner burn.
You can easily adjust the fuel and air but not so much, the heat. The heat in a wood stove comes from the fire itself, so, you need to get the stove very hot, as quickly as possible, to achieve a good balance. Wood emits gas when is heated above a certain point in a reduced atmosphere; this gas will burn cleaner than the wood itself. If you get your stove so hot that the wood gas burns before the wood, it will burn cleanly. There are cars designed to run on wood gas: a heated tank of wood chips creates the gas that runs the engine. Most stoves have a baffle or two and an upper chamber where the hot gasses will hopefully combust when mixed with additional air; the real heat is at the top of stove, before it exits the flue. In my Lämpimämpi stove, the top plate, that the rocks sit on, is 3/8” steel. I will get this steel glowing a dull cherry red (about 1300°F). Any gasses passing through this chamber will be burned. But until the upper chamber is hot, gasses and particulate will escape up the chimney and the sauna will smoke. Having a brick-lined fire chamber will help the fire get hotter faster. Wet cool days will make it worse as will a down-draft caused by the sauna being in the lee of nearby trees or structures. Wet wood doesn’t help either.
Up until this week my process has been to get a small fire going briskly, with the ash drawer open, and stove door open until it starts to roar (I have an external feed, so no worries about embers falling out.) Then I add larger sticks in one or two loadings until I fill the fire chamber (nothing bigger than my arm–scrap 2×4’s are perfect) topping it with one or two small hardwood logs. The problem is, when I add the fresh wood on top of the fire, there is a period of incomplete combustion as the wood heats up, and the stove smokes a lot. If the wind is wrong, my neighbors will get smoked out. I tinker with the ash drawer or open the stove door to blast in more air until the smoke clears (another advantage of an external feed: I can watch the chimney.) I can add more air to balance the fuel, but I can’t add more heat. Think of it like the carburetor on an old car. Too open, it won’t run well, too closed, it sputters and smokes and clogs the engine. Not enough heat, and it won’t burn well either. I try to find the sweet spot. Unlike a wood stove in a house, I’m not worried about things getting too hot- better than too cool. It’s not uncommon for my stove pipe to glow red for a while—that’s ok, because I know my installation is safe.
Recently, after reading an online post, I tried a new way to fire the stove (yes, old dogs can learn new tricks): from the top down! I load up the stove with larger sticks at the bottom, then smaller, with short sticks crisscrossing between them. Then on top of this stack I put the wads of newspaper with a handful of kindling and light that. The fire immediately starts heating the baffle and upper chamber as the fire slowly works it way down. This way the flames aren’t cooking the larger sticks before they are ready to burn. This solves the too much wood/not enough heat problem. Amazingly it only takes 5-10 minutes for the fire to reach the bottom and a hot bed of coals forms quickly. I leave the ash drawer slightly for twenty minutes and then add more wood. After that you can’t even see any smoke. When we take our sauna to one of the local parks, we can be clandestine; with no tell-tale smoke; passersby have no idea that our sauna is cranking hot inside.
I know there is a whole argument for decreasing our carbon footprint as much as possible and not burning any wood; but there is an opposing argument that says we need to maintain our ties to nature to want to save it. Controlling fire is not only as old as mankind but one of our defining traits.
Without getting into the debate, which I’ll admit I don’t lose sleep over, I will admit that I don’t want to be “that guy”. I want to remain sensitive to others and burn my stove as cleanly as I can. Learning how to master the art of fire building is one small step to take if I am going to cling to tradition and enjoy a really smokin’ hot sauna.
In order to save it, the old Sauna at Podunk had to be taken down. The squirrels had taken over and filled the dressing room with a cache of nuts. The building was slowly sinking into the earth and the safety of the chimney, a heavy cast cement affair supported in the ceiling by a rusty homemade contraption, was questionable. The gaping mouth of stove door was rusted open in a permanent state of whoa. If this sauna was ever to make löyly again, work would have to be done. So, a month ago, after careful consideration and much debate, Scarlet and I joined members of the Heila family for a day of deconstruction.
As you may recall from earlier posts, (Sauna Time, Sauna Ritual,Homecoming, Back to Podunk) this is the 90 year-old sauna where many of us locals were initiated in the joys of sauna during the heyday of the 70’s when the Podunk Ski Center was a mecca for Nordic Skiing and all things Finnish. Its simple rustic character, which addressed the basic functionality of the sauna with what I call Finnish pragmatism, is the inspiration behind much of my sauna building. The demolition would give me the chance to dissect it and uncover some the secrets of its original design.
We always thought it was the perfect sauna: hot but airy, it made good löyly, and was roomy enough for an intimate crowd of 8.
What I did not know was how the materials related to its function: how well it heat up, how it held a good Löyly and never felt stuffy, and why it never burned down. Aesthetics aside, these are essential components to a good functioning sauna. We often debated whether it had any insulation at all, so I was especially curious about that.
It was a drizzly morning with a chill to the air; ironically, a perfect day for sauna. Our plan was to document the existing structure and take it down methodically, saving what we could and carting the rest away. Eventually the structure will be rebuilt, as close to the existing as possible, on the same site. We proceeded quickly, each of us attacking an area. Beloved details like the doors and little shelves in the dressing room were labeled, wrapped and carefully stored. The barn board siding was carefully removed board by board, and the whole front facade was Sawzalled off and preserved. As the layers were peeled back, we discovered not only that there had been several incarnations to the structure but we uncovered the answers to some of the questions I had been pondering. There were several surprises.
As the walls were removed from the outside in, we uncovered many layers and each wall was different. On the east wall, under the vertical reclaimed barn boards (installed in the 1970’s?) was a layer of Inselbric, the ubiquitous and horribly ugly asphalt siding that was used starting in the 1930’s. It was easy to use and durable and is still found on many “economy” (or as my Dad would call it: “Early American Poverty”) style homes dating between 1930 and 1960, until aluminum siding became popular. This was over a layer of horizontal 1×6 pine boards, loosely spaced, which went around most of the building. Under this was the big surprise: flattened cardboard boxes, several layers deep, between rough sawn vertical framing members about two feet on center.
The cardboard was in good shape and the labels were easily read: cereal case boxes from Wheaties, Corn Flakes and others. This was the insulation we all wondered about!
A web search of the logo style led to verification of the 1935 date of construction. Interspersed with the cardboard were vertical boards with no apparent purpose. Was this to add thermal mass to the walls? The interior surface was initially all Beaverboard, an early fiber board, which was covered with a thin veneer of plaster (real plaster, not joint compound) which was painted. This was akin to the plaster and tile block sauna of Van Buskirk Gulf I wrote about in a previous blog. This would have provided a vapor resistant barrier that would have held the Löyly steam for the right amount of time. Later, in the 1970’s, this was covered with 1×6 tongue and groove knotty pine. With our current obsession over cedar (or other wood) interior walls wonder if a more authentic sauna might be simply plaster with wooden benches and back rests? The plaster and paint layers (probably lead) were vapor semi-impermeable and thus capable of holding some of the moisture. Surely all the outer layers in the walls were breathable, that is, allowing vapor to easily escape and not collect as condensation, which is a very important consideration in any kind of construction. But I did notice one corner post had signs of severe rot. Did the plaster layer crack here and allow moisture to saturate the wood, setting the stage for a colony of carpenter ants to move in?
I also noticed that, other than the entire building sinking into the earth, the walls were structurally sound. So much so that when Tom hooked up the tractor to pull the north wall off, the whole remaining building (already missing its east and south wall) simple hopped along the foundation slab behind the tractor, taking the chimney with it and sending me into a fit of laughter. All those random layers of heavy boards were keeping things together. It’s not a recommended practice, but sometimes just heaping layers of wood into a structure creates enough redundancy to make it solid. I prefer the more efficient approach of building more with less.
The ceiling was like the walls, with plastered Beaverboard covered by pine. The tiny attic space was filled with a layer of cellulose interspersed with rodent droppings, walnuts, empty boxes of rat poison and a few old bottles, which probably once contained hooch. One was verified as being from 1938 by its unique design. Probably teenagers hiding their stash after a sauna; but, quite possibly, offerings to the sauna Gods to protect it from burning down.
As for fire safety, it was a miracle that the sauna never did burn down. There was a lot of charred wood throughout the attic, especially around the iron chimney supports.
Again, there were a lot of heavy boards, which seemed to have no structural significance, perhaps only adding thermal mass or insulation. The roof rafters were so heavy and the roof so strong that after it was lying on the ground like a low pup-tent, Tom had to drive the tractor over it to break it apart. The metal standing seam roof, with its many coats of black tar, was in surprisingly good shape, but leakage was occurring where the heavy, cast refractory cement chimney penetrated it. The stove below, welded by me in the 1990’s, was so rusted it was deemed to be scrap.
The cement floor had sloped to a drain but was cracked and broken. The original cement pour seemed hodgepodge and lacked any re-bar. Woodchucks had tunneled voids underneath it. The drain allowed for bathing— something the early Finnish farmers needed as the house probably lacked plumbing; bathing, to me, is an essential part of the sauna experience; that function of the sauna informs my designs. The floor will be replaced with an edge- thickened slab as the foundation; with a solid gravel base over undisturbed earth and with steel reinforcement.
The one component that perhaps was a factor in why the sauna felt so good was all the brick work around the stove, which was fired through the dressing room wall—a traditional design I frequently use. This added about a thousand pounds of thermal mass around the stove. Thermal mass holds the heat and radiates it back into the room but also means it will take longer to heat up. I typically use a lightweight fire wall so the sauna will heat quickly and to lessen the load on the building structure, but perhaps I should re-think that and revert to the solid masonry I started building with in the ‘90s. Ironically, the brick work at Podunk was added in the 70’s. The old Finns around here commonly relied on asbestos board for fire protection.
By the end of the day, we had a pile of barn boards and other parts stacked and labeled in the old ski lodge, and a dumpster overflowed with the rest. Although most of the sauna was discarded, the lessons learned will live on in the saunas I continue to build. Next year, we will rebuild Podunk with modern efficiency but in the same basic footprint as the original. Hopefully the entire facade will be replaced and the lilac tree where the sauna bell hung replanted. We’ll probably skip the lead paint and asbestos board and use a modern, UL listed chimney support in lieu of the home-made rig that was there. Fire safety will be based on science, not luck. Cedar over foil (with an air gap!) will line the walls and the functionality will be the same, and hopefully, better.
Family and friends will gather there to sweat and bathe and run naked to the creek for generations to come.
If you look “Podunk” up in the dictionary, it will tell you that it is a hypothetical or insignificant town. The folks who live there think otherwise. Podunk is actually a place name on the map a short ski south of Trumansburg, New York, where I grew up. Despite having only a smattering of residents, they will all tell you that is very real and very significant.
In the 1960’s Ozzie Heila settled there with this family on an old farmstead established by an even older Finn who first built his sauna (above) before the house in the 1930’s. It is also where I learned of all the important things in life. In the 1970’s I spent countless winter hours there at the ski center that Ozzie established, becoming a become a damn good Nordic skier and developing a life-long passion for the sport.
In the summers I explored the creek with his son, my good friend Daniel, and learned the value of immersing one’s self in nature. Daniel’s mother, Ethel, was my art teacher in middle school; she helped me become the artist I am today and we still have wonderful conversations about color theory and art composition. And at the heart of the complex of dated farm buildings was the sauna; there I learned to channel my need to experience extremes into something healthy and life affirming. We loved going from the hot to the cold.
Jumping in the creek in the dead of winter after a searing round in the sauna, we felt more alive than ever. That feeling has never died; each cold plunge I take during sauna takes me back to that creek.
Today, Daniel and his family were back in the area and we went to Podunk to visit the old homestead once again. This time we took our Finnish Blue mobile sauna and parked it next to the ramshackle old sauna, which is now defunct and awaiting a rebirth. Many things have changed but some things are the same. The trees have grown huge or even died, the old purple Lilac, with the rusty sauna bell hanging from its branches, is gone and the brush has been cleared away from the old sauna, revealing the sagging bones of the century-old structure. But the building itself is as recognizable as the last day I took a sauna there about 25 years ago. The inside is a sadder story—it turns out that squirrels like the sauna too and they have made it theirs. As if in a expression of horror at the mess, the Lämpimämpi stove I welded up for Ozzie in the 90’s sits with it’s mouth rusted wide open.
The path through the field to the creek is the same but with a detour to the left towards a new dipping hole: a bathtub in the midst of the rushing current with a strategically placed rock to help keep your butt moored. The run down to the creek had the same awkwardness … trying to run all out before you cooled off but trying to maintain stable footing the same. And the sensation! The whoops and hollers of 12-year-old boys came out of us as we braved the icy April stream.
Real or not, Podunk is the same as it will always be. What are memories but unreal fragments in our minds, ready to be stirred up by whirling waters of a cold stream, or by the hot steam of a sauna? The old next to the new will always appear old, until we make it new again and live our lives in the now, to the fullest, with no regrets, and dreams, not of memories, but of tomorrows.
New sauna and parked it next to the old sauna near the creek.
Learn how to build saunas and gain expert knowledge from master builder Rob Licht in an intensive 4-day class experience
Dates: SPRING class! May 1-4, 2025
This is a comprehensive sauna building class and workshop with demonstrations, lectures and some hands-on experience. We will cover many aspects of building saunas including:
Design and layout of saunas: Freestanding & Electric Saunas
Selection of the proper wood and other materials
Insulation principles
Interior wood paneling
The kiuas or sauna stove (emphasis on wood burning)
Safe clearances and chimney installation
Floor and stove wall masonry construction.
Mobile saunas
Benches, doors, windows and other sauna details
Using the sauna: usage, custom and etiquette
sauna culture, business, construction challenges and more… !
Total Class Fee: $900 individual $1700 couple/family rate
A $100 non-refundable deposit is due at registration and applied to the class fee.
Location: At the Shop of Rob Licht Custom Saunas 8 Verizon Lane, Unit 1, Lansing, NY 14882
Class size will be limited to 12. There will be a waitlist. Please email us at contact@roblichtcustomsaunas.com to get on the early registration list and we will let you know the dates asap.
Class Schedule: Thursday: 10AM to 5PM, lunch provided Friday: 9AM to 5PM, lunch provided Saturday: 9AM to 5PM, lunch provided Sunday: 9AM to 1PM, lite brunch provided
Throughout the intensive days we will have break-out work sessions, time to answer questions, and coffee breaks. There will be opportunities for socializing after class and the option to take sauna at the shop and by the lake.One evening, we will sauna and picnic at a local park on Cayuga Lake. Significant others are welcome to join us for this event.
Recommended prerequisite: We’re not covering basic carpentry (exterior framing), and basic metal working. If you lack these skills it is advised that you take a hands-on carpentry class.
About the Teacher: Rob Licht has been taking sauna for 50 years and has built and designed hundreds of custom saunas. Rob readily dispenses his knowledge to students and hopes to share his enthusiasm and expert knowledge of sauna with you.
Rob Licht grew up near Ithaca, N.Y., inspired by the bucolic landscape of the Finger Lakes region. He fell in love with sauna and Finnish culture as a teenager at a local cross-country ski center run by a Finnish family. He has a Master of Fine Arts Degree from Cornell University and has been a practicing artist and teacher for over 30 years. He taught art at Ithaca College for 12 years and has also taught adult education classes in welding, art, and design. He began combining his love of sauna, his practice as an artist, and his skills acquired from working in the building trades into a sauna building business in 1995. Today sauna building is his primary focus and he is one of the leading east coast sauna builders and sauna building educator offering a plethora of information to his clients, and now students, from around the world.
Terms & Info: A $100 non refundable deposit is due at registration payable paypal/venmo and applied to total class fee. Your balance is due (via mailed check) at least 45 days before class in order to attend. We realize that check writing may be a thing of the past, so are other options via paypal but ask that you cover the 3% paypal fee. We will also accept cash for the balance when you arrive, just let us know if you are planning on that so we can plan for your attendance. In the event the class is under enrolled (6 or less), you will be informed and your deposit of $100 will be refunded. In the case the class is over enrolled (12+) we will put you on a waitlist and we will let you know asap if you can attend. Because of the overwhelming popularity of the class, there is a waitlist, so if you do need to cancel please keep that in mind so we have time to fulfill your spot. Class size will be limited to 12. Class attendees will have the opportunity to buy our sauna building plans at 50% off.
About the Shop: 3000 sq ft with 16 ft ceilings and two large overhead doors and outdoor spaces to ensure good air quality.
Lunch is included: Lunches will be delivered to the shop. We will accommodate basic dietary restrictions with options. Coffee, Tea and snacks will also be available throughout the days of the class.
Sauna etiquette: We allow about 4 people at a time in the sauna. Bathing suits are required; please bring 2 towels (free from perfumed detergents) to sit on in the sauna. Towels will also be provided everyday. Everyone will get a chance to sauna most days after class.
WHAT PEOPLE ARE SAYING…
“This was the best weekend. I learned so much and left feeling full of inspiration and conviction. We can do this y’all- the revolution is happening! I am so grateful to you, Rob and Scarlet, for working so hard to put together such a clear and digestible roadmap for all of us. And I am so grateful for having four days with the loveliest people to talk sauna. What a dream.” —Erin, NC
“What an amazing weekend of sauna immersion. It was something special to be in an intimate group of like-minded folk focused on something that brings us such joy. Rob and Scarlet so well prepared and so packed with knowledge and hands-on experience! I was so impressed with the smooth and thoughtful delivery of information. Possibly the biggest take away I got was that there are many right and not so right ways to do things, in the end sauna building is an art as much as it is a science, which is why my sauna is so authentic in the experience.” —Mark, MA
Rob and Scarlet are the real deal! I’m a professional carpenter and builder. I bought and adapted Rob’s mobile sauna plans, and I also did a consult with him. Two years later, and I’ve just had the pleasure of spending 4 days in the shop with Rob, Scarlet, and about a dozen other students, drinking from the firehose of knowledge and experience. They make a great team, both as builders and educators, and they’re just great people to be around. I couldn’t be more pleased and impressed with the experience, and I’m eager to get back to building saunas back on the west coast with my business, Sauna Väki. —Josiah, OR
Traveling with one of our mobile saunas to the lake and delivering to new owners.
We have been building mobile saunas for the past 10 years! and because of their growing popularity and versatility, they now make up most of our business. Each unit is still handcrafted with many layers of details. The owners each get a unique product tailored to their specifications. It’s also an easy way to avoid zoning and permitting restrictions while avoiding the hassles of a site-built project. Investing in your dream sauna makes more sense if you know you can take it with you!
We hear from our customers all the time that their friends, family, and neighbors are as excited as they are to have a sauna!
mobile sauna, wood-fired sauna on a trailer
For many people, owning a sauna feels like a bare necessity during the winter months!
This recent sauna build is just steps from the owner’s historic New England homestead. Our saunas are designed to blend in with the home and environment. The classic details of this historic house are elegant rustic with dramatic rock outcroppings and a fire pit, making for a perfect gathering spot.Our wood-fired mobile saunas travel well and can be parked in beautiful placesScarlet by the lake ready for a cold plunge
Having a sauna at home is a life upgrade that is low-maintenance.
Our 5×8 ft Mobile Sauna parked in town with 100 gallon cold plunge tank.Interior of our larger mobile sauna. Our saunas can get as hot as you like with a large pile of rocks. We aim for 100°C / 212°F We build many mobile saunas in our shop in Ithaca, NY. Working in our 3000 square foot shop is more efficient than building on-site.Two sizes of mobile Saunas on display at our shop in Ithaca, NY
We offer building plans for DIY sauna builders or your local builder for one-time usage only. Thanks to our valued sauna plan customers, and the growing popularity of DIY sauna building, we have taken the opportunity to launch our new & improved mobile sauna building plans! Our sauna plans are 50+ pages and include detailed notes, drawings, photos, and material lists for a wood-fired 5’x8’/6.5’x10′. If you are thinking about purchasing our plans or building a sauna, we offer you an opportunity to build your own sauna using construction plans. Rob Licht has developed the best practices of sauna building with 30+ years of experience.
When we think of Sauna, we generally think of a wood-lined room heated by an electric or wood-fired kiuas (even though my last post was on the discovery of an old smooth plastered sauna.) The wood is integral to the experience—for the aesthetics of its look, its pleasant smell, and ability to take the humidity and temperature extremes. But all wood is not alike, and the question of what kind of wood to use always arises. The answer to that question, like everything else these days, is changing.
Typically in the US, especially in the generic gym and hotel saunas, and home kit saunas, Western Red Cedar is used. As its name implies, it is from the western US and Canada. All lumber is graded and each board is stamped as it runs through the mill. The grade indicates species, appearance, mill, and strength of the wood. The letters A-D are modified by Select, Clear and STK (select tight knots). For cedar saunas, it will be either a clear select grade or STK, the latter being almost half the price of the former. Cedar is also produced mainly for exterior siding applications and comes with a textured surface on one side that, unlike the sawing pattern of rough sawn lumber, is applied in the mill after sawing. This rough surface is considered the “good” side to which the grade applies. A big frustration with cedar is that I want the smooth side facing out and, since the board is graded to the other side, there is no guarantee that the smooth side has the appearance that the grade indicates.
Western Red Cedar, graded clear select with many variations of color
Color in cedar varies a lot: one side can be red and the other have annoying stripes of white wood. Clear select grade A boards will be better, but they come at a premium price, currently about $12-15 a board foot (12’x1 ft x1” thick, nominal dimensions). For years I have typically used Western Red STK for the walls and maybe Clear Select grade on the benches. This wood comes from either Idaho or British Columbia (BC). STK is likely from managed (regenerated) forest plantations and Clear Select is from larger old growth trees in BC. There is a guilt factor here I consider, so I veer towards STK whenever possible. (I also use Northern White Cedar frequently in freestanding saunas and our mobile saunas but that is the topic of another post.)
Cedar has been touted for its stability in the heat—which is true, and because of its low density, it doesn’t get hot to the touch—an important feature in a hot room with bare flesh touching the walls and benches.
Wood is a global commodity affected by the stock markets, inflation, building trends, shipping woes, fire seasons and the whims of political leaders who set tariffs as a way to taunt each other. You can make a career (and people do) out of studying the ebb and flow of lumber supply and prices. Add to this mix the pandemic and you have a roller coaster of unpredictability. The information I gleaned from building ten or twenty years ago I can no longer rely on. Suppliers have come and gone, quality has gone down and prices go mostly up.
The Pandemic created a real change in the labor force as well. There was never a shortage of raw lumber-logs but as workers and truck drivers got sick or just quit, mills shut down and logs piled up. The calculus used to predict building trends was skewed by everyone staying home and building decks with their pandemic relief money and we all saw prices soar while availability of lumber, especially cedar, shrank. In the meantime, the cedar I could get has been showing up with major defects, some from the mill, some from very poor handing: fork lift stabs are so common I have to over-order for very job. I assume this is the result of experienced older workers leaving the work force and being replaced by a cohort too inexperience to understand that the 6-board bundle they just mangled cost me more than what they make in two days. Some days I feel like all I make is very expensive kindling.
Cedar, graded side up (rough) with shipping damage
The truth is, in Finland, the source of my sauna inspiration, they don’t even have Western Red Cedar. They have soft wood species similar to what we have—spruce, pine, fir (SPF) but, in general, the quality and nature of wood varies by region. Wood from northern climates grows slower and has a denser grain.
As in Scandinavia, trees in uniformly dense forests have straighter grain as the trees race to reach up for the sun. Compare a “lone wolf” white oak, with its sprawling branches, to a deep forest oak.
Norway Spruce is the wood choice for many Finns, as are Alder and Aspen, which are soft hardwoods. The latter grow bigger there than our typical Aspen and Alder which rarely found at local mills. Cedar has been touted for its stability in the heat—because of its low density, it doesn’t get hot to the touch. But now Scandinavians have started using a thermal process of using heat and steam to modify wood and make it more stable and rot resistant (or so the web pages claim). I suspect there is also a Scandinavian work ethic at play: working in the trades there does not carry the same stigma of being a high school dropout, as it does here, and attention to detail and quality are paramount. Call it the IKEA effect.
Thermory and Lunawood are two brands available now in the US. The shipping crisis (highlighted by a boat getting stuck sidewise in the Suez Canal) has calmed down so now the economy of having quality wood freighted in containers from the Baltic’s to you (via a US distributor) probably makes more sense than wasting your time perusing the aisles of a big box store (or several) to glean out a few good cedar boards from a pile of fork lift-stabbed firewood. I also measure the time I spend trying to hide defects as I install the wood. While I still want to get all of my materials as locally sourced as possible, we are now in a global economy and looking abroad is certainly starting to make more sense to me. —Rob
Beautiful samples of thermally modified wood using heat and steam
The town of Newfield, just south of where I live, is known for its rolling hills, deep gullies and rugged forest. When I used to live there I’d ramble about the woods and back roads that thread their way through sparsely populated forest. Just south of there is Spencer, known for its many Finns who settled there in the early 1900’s. Mostly these Finns came east from Michigan in search of better farmland and a life that did not include mining. You can still make out saunas behind the old farms: small wooden outbuildings with a tell-tale-chimney. Some are still in use; others are slowly falling apart, as rural structures tend to do.
At the bottom of Van Buskirk Gulf, on a stretch of seasonal road, next to the creek, is a curious arrangement of structures. One is a beautiful old stone bridge dating to 1818— the oldest in the county— that was restored several years ago. Overlooking this is an abandoned stone house; the windows shuttered with plywood and the insides littered with graffiti. Although it echoes the stonework of the bridge, county records show it was built in 1865.
Across from the house and alongside the creek sits the main object of my curiosity— an old steam sauna or banya.
Unlike the old wooden saunas, this building is built from tile block and concrete with a beautifully plastered interior. The plaster, which is over metal lathe, has a smooth eggshell finish that is only typically found in high end homes that predate the use of drywall or plaster board. The metal lathe came after the use of wood lathe. My Guess is the 1930’s-40’s. The layout has an entryway where one would undress and relax. A room to the side has a small door in its far end leading to a fire chamber below the sauna room. This is where the firewood must have been stored and the fire tended to. Beyond the dressing room, up three steps, was the bathing room. It is all plastered, including the bench, with an arched ceiling and soft curves. In the center along the interior wall, above the fire chamber, is the heater that features a large rock chamber.
The fire would pass over these rocks until they were ready to use, then, once the fire died down, the iron lid was lifted and water would be thrown on the rocks to produce steam.
This is the same as modern heat storage heaters. A side door from the dressing leads directly to the creek. Remnants of a heat exchanger tell me that hot water was also available to bathe with.
Up the creek is the remains of a large dam structure. Was this a work camp of some sort? Were Finns (or Russians) employed nearby? Was it a mill site? Perhaps it was built during the CCC (Civilian Conservation Corps) era of the 1930’s when many trails were built in nearby parks. I can imagine a group of workers enjoying the steam bath after a hard day’s work and plunging into the creek. I can also imagine fixing it up and returning it to use. If anyone has any answers, please share them!
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Reference: Melissa Ladenheim, The Sauna in Central New York, Dewitt Historical Society of Tompkins County. Ithaca, NY 1986.
Mobile Sauna Interior with the Lämpimämpi sauna stove, tiered benches and large window with a beautiful view of the fall foliage. Wood-fired from the outsideLämpimämpi sauna stoveStick hardware by Rob Licht
Stay posted on the latest Finnish-blue mobile sauna outings on Instagram @saunasbyrob and facebook @custom-saunas We’ll be using this one for pop-up and promotional events in the Finger Lakes region of New York State to share our saunas and promote sauna culture.
PRESS INQUIRIES: Contact Scarlet at contact@roblichtcustomsaunas.com
We just finished this sweet sauna: an eight by eighteen-foot building with an ample dressing room, large hot room, and wood storage on one end, all on a 12×20 raised deck. The site is near a cabin and a nice pond, all on a remote hilltop in the Finger Lakes.
The design and the craftsmanship were driven by the concept: a weekend retreat from the bustle of life, removed from technology and the stress of the 21st century. Nestled in nature, the sauna has windows to let the light in and open the view to the woods and pond.
We kept it simple, yet well crafted and elegant. The sauna functions as a centerpiece to the family gathering place and also serves as the bath house—since they are eschewing modern conveniences like running water.
Henry David Thoreau may have had his pond, but what he really needed was a sauna.
The landscape of Upstate NY is punctuated by the rural agrarian architecture typical of an area rooted in 19th-century traditions. Massive old barns reign supreme and are typically surrounded by a cluster of smaller accessory buildings: smaller barns and equipment sheds, dairies, smokehouses, and, occasionally, if one looks hard enough, a sauna. Sadly, many of the wood-sided buildings have either burned or fallen into abstract heaps of their formal selves. Their replacements— metal-sided Morton buildings and giant fabric-covered hoop structures—are strictly utilitarian and lack the romantic appeal of the old barns. It is the former that inspires the creative in me.
When I was an aspiring young artist, old barns were often my subject matter. My father and I would go for drives in the country and stop to draw landscapes with a barn as the focal point. Now, when I build my saunas, the vernacular of old farm structures is never out of my mind. In particular, I am drawn to the older simple gable roof structures, rather than the more efficient gambrel roof. There is something pleasing about the simple geometry and the formal balance in earlier barns. When additions were made they typically created a hodge-podge of shapes and the formal symmetry was lost.
Rob stands next to and old saw blade waiting to be refurbished.Rough cut 1×12 Pine for Sauna exterior
The barns were typically sided with local pine, nailed vertically with green boards nailed closely but with gaps that would open as the wood dried. These gaps were often covered with narrow battens that were nailed so that the boards could shrink and swell. This is the beauty of board and batten siding: it takes into account that the wood is alive and not a fixed entity. It is this board and batten technique, or variations of it, like reverse board and batten or vertical shiplap, that I often employ. Nailed correctly so it can move, the wood will last for one hundred years, as is evident in many of the old barns still standing.
The best part of this style of siding is that it typically employs local lumber. Most rural towns have a sawmill nearby. In our region mills typically cut White Pine and Hemlock. I rely on a sawmill that has been in operation for 50 years: Collins lumber in Alpine NY. It was started by Bob Collins and continues to be operated by his nephew. The same saw has provided siding for hundreds of barns, sheds, and other outbuildings in the area. What is distinct about the operation is that they use a traditional circular saw. Many newer sawyers use a bandsaw mill, perhaps even a portable unit they can bring to you. What I like about the wood I have been getting from Collins for the past 30 years is that there is a character to it. The circular saw marks on the rough sawn boards create a pattern that has repetition but also pleasing randomness—like jazz. Certain saw teeth will mark more than others. No two boards are alike. It’s not like metal siding, cement board siding, or any manufactured material typically used in construction these days. It speaks of the trees, the mill, and the rural landscape.
It’s the kind of thing you might never notice, except when you come out of the sauna and have time to stare at the inconsequential things in life while you cool off in the fading light of day with the sunbeams raking across the swirling marks left by an old saw blade.
If the heart of the sauna is the kiuas, or sauna heater, then the soul is the rocks.
—Rob Licht
Every brand of heater I’ve installed has a different approach to the rocks. Some, like a wall hanging 6 or 8 kilowatt unit, use less- maybe 40 pounds, and some, like the Harvia Cilindro or Club heaters use more— up to 200 pounds. Wood burners vary too, Kuuma’s heater takes 150 pounds or so, but you have to provide your own. My own custom built stoves ( Lämpimämpi ) take a similar amount and like the Kuuma stove, the rocks are piled on top, mounded as high as you can. The Harvia Legend, an elegant wood burner from Finland, basically has a cage that surrounds the stove. By the time you are finished loading it, you won’t see the stove. There is even an optional cage that surrounds the stove-pipe to hold even more rocks.
The Finnish and Swedish heaters use Olivine Diabase or Peridotite, igneous rock found in Scandinavia. All of the rocks I have used that come with the electric heaters look the same: grayish chunks, some flatter, some chunky, all in the size range you’d find in a bag of potatoes. These are amazingly cheap considering that they come all the way from some quarry in Finland or Sweden. The UPS driver has stopped asking what is in the boxes (“yup, rocks”). Once I found a note in one from a young Swede hoping that I was happy with my rocks.
My favorite rocks are hand selected glacial erratics: various igneous granitic and metamorphic stones that I find in places where glacial melt-waters sluiced out potato sized rocks. (shown below) These are heavier and denser than our native shale, which is worthless for the sauna since it tends to explode when heated. They have a crystalline structure that you can usually see and a solidity and heft that is evident when you pick them and bang them together (they are not easy to chip.)
Lämpimämpi with Glacial Erratic RocksLämpimämpi with Jagged Olivine Diabase Rocks
A big consideration when selecting a heater is the rock capacity. The more rocks, the longer you should let your sauna heat up. Clients always ask:” how long should we let it heat up?” While I usually say “about 45 minutes” I really want to answer with the same sort of retort I give when someone asks how long will take for paint to dry (as long as it takes). The correct answer should always be: the sauna is ready when the rocks are hot enough to produce good löyly or steam—löyly is the soul of the sauna’s mysterious expression. And how hot is that? 450° Fahrenheit, more or less. If you want more steam, then you want more rocks.
Löyly is the soul of the sauna’s mysterious expression.
—Rob licht
If you expect several rounds or people coming and going, then more rocks are good. No one wants to pour water on the rocks expecting a stimulating burst of steam (but not too sharp) only to hear the fizzle of water barely boiling. That’s like trying to make an omelet in a pan that is barely hot. Disappointing, to say the least, but also bad for the heater. There’s Finnish saying that goes something like this: when you leave the sauna put another log on for the sauna elf or he will pee on your stove. Which means, don’t keep throwing water on the stove, especially at the end, if the rocks are not hot. The warm water will just sit on the steel stove and rust it. When you throw water on the rocks, it should all turn to steam and when you are done, the stove should dry quickly. When I finish eating my omelet, I rinse my cast iron skillet and let it dry over the flame, I don’t let it languish all wet in the dish rack; same principle applies to the sauna stove.
Jagged rocks will catch and momentarily hold more water, allowing less to get past the rocks and into the heater. The dense roundish rocks I use produce a nice soft steam but they have to be hot. I’m not so worried about water getting down to my stove, which is always very hot (and mine have 3/8” steel plate on top so they will never rust out). By the way, always use clean water and be wary of city water with chlorine or even country water with minerals or methane. We use only use filtered water for löyly at home. Spring water or distilled water might be prudent in some cases. Never use pool water or worse, let some disrespecting novice wring out their bathing suit over the rocks, as I have seen happen in a gym. Pleasant smells should emanate from the rocks. Special sauna oils or even Sauna Brew can be added to the löyly water for aromatic effect. Heck, we used to add beer to the water (cheap lager was always best).
Custom Sauna with Harvia Cilindro with carefully placed olivine rocks.
If your electric heater comes with the grey jagged olivine rocks, I suggest using them. They are selected to fit between and around the elements. When setting the stones first I rinse them, then I take care to arrange the rocks one by one. It can take me 45 minutes to fill a large capacity heater. For the Cilindro, I place large rocks at the bottom to hold up the others and then work a flattish layer against the cage wall. I then backfill the rocks against the elements with smaller and irregular rocks. On the smaller wall-mounted units I try to fit the flat stones between the elements without forcing or bending them. The goal is loosely fill the cage so there is good airflow and to completely conceal the elements. Lastly, I top off the heater with larger stones and try to arrange them so they will catch water and force it inward, not splashing it out. In Finland there might a “spirit stone” placed here: a special stone or stones from a favorite place (make sure it is igneous or metamorphic—test it in a campfire first if not sure). The top might even have a layer of more decorative stones, which in Finland you can buy from sauna dealers, but here in the US, I have only seem the same dull grey stones. The Harvia web page has a good section on stones and how to place them into the pillar.
Once you have the sauna going and have been using it for a year or so, expect the stones to settle and flake off. You should remove them, vacuum out the heater and replace the rocks loosely, discarding the broken ones and adding more if needed. Failure to do so will cause the heater to eventually overheat and lead to the elements failing.
Care in selecting and placing the rocks will ensure that your sauna…. Rocks!
Wood-Fired Mobile Sauna by Rob Licht Custom Saunas.
Although Glamping is a term that was coined in the early 2000’s, the concept of an adventure in nature bolstered by all of the modern conveniences one could muster, or have mustered for them, has been around for well over a century and a half. In 1869, writer William H.H. Murray of Boston, extolled on the virtues of experiencing the Adirondack backwoods in his book Adventures in the Wilderness. This inspired an avalanche of urban neophytes to flock to the woods in search of adventure and commune with nature. These were known as “Murray’s fools”.
People traveled great distances and endured great hardships such as days of travel over log roads (which were literally made of logs placed side by side) to get to the heart of the Adirondacks. Once they arrived, they sought out the services of guides who did everything for them—transporting them in their guide boats, making camp, catching and cooking their meals. In essence, these early Glampers brought with them from the city every expectation of service they would get at the finest hotel.
“The mountains call you, and the vales: The woods, the streams, and each ambrosial breeze that fans the ever-undulating sky.”
—Armstrong, Art of Preserving Health
Glamping experience enhanced with a sauna (banya) in tow.
While part of me chuckles at the concept of Glamping with it’s pretense of tender-footedness, part of me is drawn to concept of rustic luxury. Although I am as far from a camping neophyte as one can be, with years of deep woods experience and many a night sleeping on hard ground, the concept of luxury camping does have certain appeal to me now. I’ll sleep in a tent on a platform—with lights and heat and maybe a commode. But better yet, with a sauna.
The idea of communing with nature combined with sauna is perfection—and something, I bet, even the luckiest of Murray’s fools never had.
View of the mobile sauna looking out through the dressing room to the campsite. Pile of rocks sit on the Lämpimämpi stove.
Most people glorify the act of building, as in being able to transform a humble pile of building materials into a noble sauna or house or shed. I like to think that too: that my profession is a noble one, with an emphasis of craftsmanship and attention to detail that can only be honed by decades of working with fine materials. But the truth is, on any given day, on any given project, especially for on-site work, where I take my tools and materials, my truck and trailer, my lunch and my laptop and various other accoutrements, is that I am often just a professional schlepper. And I bet any other contractor reading this just now nodded his or her head.
I love doing saunas that are removed from the house, perhaps beyond the garden gates or down by the lake or out in the woods next to a pond. I like to work immersed in nature, take lunch by the water, and contemplate the finer things in life while I toil at my craft.
Sauna on a PondSauna on a LakeSauna in the Woods
But, when I bid jobs like these, I have learned to think of the schlep— that is the sum total distance from truck to the site. I think of thousands of steps back and forth to carry lumber, to retrieve the pencil or glasses from the cab, of the steps I have to climb or the potential for slipping and falling with a 100 pound load on my shoulder. I have literally carried an entire eight by twelve sauna on my shoulders, load by load. Some days I count the steps and do the math—how many miles I wonder? Other times I count the load— a ton of concrete mix, how much work was that?
I don’t mind the schlep. The key is to embrace it. If I know from the start and plan for it: clear the path, remove obstacles, make ramps, then I can proceed slowly but with the steadiness of a Yoga master moving through a progression of poses. Each repeated carry is perfected in the same way a bobsled driver learns to lean through each curve.
With two or people it is a choreographed movement. Go left here, stoop here, K- turn at the end and dosey-do before we enter the door. Perfecting the movement makes it almost enjoyable.
At 60 I have to protect my body. I know my strengths and limits and my strength is knowing how to carry and move heavy objects. Always keep one hand free- you never know when you’ll have counter an off- balance step. Always be relaxed and take smaller loads— there is no race. It is amazing what you can in an hour of honest schlepping. Ironically when I do have spells of days or weeks when my back is “out” and the chiropractor is needed, it always the stupid stuff that gets me: desk work (I stand at my desk now), shoveling snow or that heroic effort to rake all the leaves in one Sunday. These are unintentional actions. Work with intention and you will become stronger. Work smarter and you will avoid injury. I really like those 60 pound concrete bags— and I’m eyeing those forty’s. At 19, everything came in 100’s.
Rob – der schlep
I’ve had jobs where the schlep caught me, like the sauna-cabin in the woods where I was promised an ATV to haul everything. After the first week, 3 feet of snow put the brakes on that. Everything had to be hauled on a sled with me in snowshoes. Good thing I Loved those Jack London stories as a kid.
But then, I’ve been pleasantly surprised too- like a recent job on the lake where the haul was several hundred feet down steep stairs or a windy path. Then the owners produced a golf cart. It became my mini-truck and my morning joy as I breezed down the hill silently. There is a beauty to electric vehicles: the joy of still hearing nature as you whizz through it.
I’ve thought of offering classes on Schlepping—or even rigging—which is a specialized form of schlep that involves more weight, more dance, more cooperation. We would move things each day. And then maybe move them back again. Everyone has it wrong about Sisyphus. If the enjoyment of the act of moving becomes the goal, rather the completion of the act, then he could be seen as a master perfecting his craft. Like a cat that keeps hitting the toy away only to chase it again, a worker who carries load after load and enjoys the process will reach the goal of enjoying his or her work.
And only when a worker enjoys his or her work is true craftsmanship possible.
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Recently I posted a picture of the sauna fire burning hot and mentioned Sam McGee. For those who don’t know, Sam McGee was the sad character from Tennessee who could not take the cold of the Yukon in the poem by Robert Service: The Cremation of Sam McGee. His last wish was to be cremated, a task his friend dutifully tried to complete. The ending had the narrator peeking into the make-do crematorium in the boiler of the derelict ship stuck in the ice on Lake Lebarge and finding his late friend as warm as could be and calling out to shut the door.
Whenever it is extremely cold out, as it has been recently, I think of this poem and the warming power of a hot fire. I love it when the mercury dips below zero. There is something invigorating about having your snot freeze when you breath hard or having sweat icicles dangling off of your brow. I love cross-country skiing in the dark, in the cold, when two hats and two pairs of gloves are needed. One false move and the night might end like “To Build a Fire” by Jack London, another favorite read from Middle school—when I would dream about all of the great explorers who ventured into the frozen lands.
walking through the snow towards a hot sauna fire
I remember my senior year of high school when Cayuga Lake last froze over. That was a cold year. We did a lot of cross-country ski races that year. With our skimpy race suits and tiny boots we had no protection other than the fire in our hearts to keep us from freezing to death. During the Canadian Ski Marathon that year it was minus 40 at the 8 a.m. start. Celsius and Fahrenheit. If you blinked too long your eyes would literally freeze shut. Old lady volunteers would slap our cheeks at checkpoints to make sure we didn’t have frostbite (and we still wore our skimpy suits.) By the end of that year my parents had moved to the heart of the lower Adirondacks. Our house, in the Black River valley, was often the coldest spot in the lower 48. It was minus 25°F for days on end. Thunder would boom from the river each night as the ice expanded. The ice was several feet thick; I have no idea how the fish survived. I loved to be out in that: skating, skiing, or snowshoeing. It was the cold of a Jack London Story. Your spit would literally freeze in mid air and hit the ground with a crackle.
I had a hot sauna to crawl into after our ski races during that cold winter in high school but not in the years after. When I moved back to the area after college, I went back to that sauna at Podunk weekly until I could build my own and have kept up the ritual ever since. On these freezing nights it is never too cold for a sauna; in fact I relish those times when you can experience the 200° (or more) difference as you go from the hot room to the night air. Your feet freeze to the ground and your hair forms punky icicles.
There’s no need to wait until you are cremated to be truly warm; Poor Sam McGee, if only he had a sauna!
It’s been a busy year at Rob Licht Custom Saunas and as the holidays approach it is a good time to look back everything that’s been accomplished, the hurdles we’ve gotten over, and to be thankful for the blessings we’ve received.
We started the year in the midst of the pandemic which made for some challenges but mostly the pandemic has meant a huge uptick in the sauna business as we all became more centered on home life and more reluctant to go out into public for things like gyms and saunas. Besides the several projects I have completed locally and around central New York I have fielded calls and emails from folks desperate to have their own saunas from as far away as Europe and Australia. I never set out to become a sauna expert, but here I am, 25 years into making them, and people are seeking out my knowledge from all over. In the process I feel like I have made many new friends. The global sauna community is alive and well. At the same time, due to the pandemic, I have mostly refrained from seeing all but my closest friends and family. It’s a strange new world but I am thankful to be connecting to so many people, if only on Zoom.
For my new friends I have designed and consulted on saunas from Maine to California— that has kept me busy when I was not getting my hands dirty. But whenever I can, I am working with my hands, either in my 3000 square foot shop, which I am ever grateful for, or I am on jobsites. It used to be that builders would simply stop in the winter and spend the dark months sitting around the woodstove reading back issues of Fine Homebuilding, but now we all seem to be out there in any weather. My cut off is 10° F; any colder and I want to be by a fire, in the sauna, preferably. Good gear helps; I’m especially grateful for my boot warmer and insulated pants.
Mobile Saunas showcased in the shop. Lansing, NY
Nothing I do is cookie cutter—I would die of boredom is life was too easy— thus the custom in my business moniker. This year I seemed to run the gamut of sauna permutations: First, a garage retrofit to a Yoga and sauna retreat, then a quiet walkout basement electric affair, then a classic one room wood burning sauna on a idyllic creek, then a more urban collaboration in Syracuse, followed by a tiny personal electric sauna in a bathroom, a rustic elegant wood burning retreat in the trees, and a distance job downstate. Currently I’m finishing up an electric sauna in a historic boathouse on Cayuga lake. I’m hoping to take it for a test drive, with a jump in the frigid water, by Christmas.
Garage Retrofit for Hot Yoga and SaunaClassic Creekside Sauna set 50 ft from swimming hole. Idyllic.Walkout Basement Electric Sauna BlissBackyard Sauna Design, Urban Collaboration in Syracuse, NYRustic elegant wood burning saunaCozy interior of a backyard sauna
In between all of these I have sold a few of my Lämpimämpi sauna stoves and many sauna plans. DIY interests, especially in the mobile saunas which are really big now. I get a kick out seeing my designs being brought to life by many different hands. It is also fun to see all of the other builders following in my steps. The more builders, the better. There is plenty of work to go around and I encourage anyone who wants to take the work seriously to pursue it with a passion. I did offer a sauna building class this year but had to cancel; Covid has thrown a wrench into a lot of plans. But stay tuned: perhaps 2022 will be the year.
Covid also threw into a wrench into the supply chain. We’ve all heard the phrase “supply chain disruption” by now. I bid jobs in the beginning of the year only see to prices on materials I quoted go up by 250%. Some materials simply vanished from the shelves. But now things have settled down and I also started ordering and stock piling materials well in advance. I can keep several saunas worth lumber and supplies in my big shop and insulate myself from some of the inflation—another reason to be grateful for the big work space.
Rob at the shop!
I’ve been working alone for most of the year, which actually suits me fine, especially with Covid lurking. Workers are hard to come by: not only are the skilled trades losing new blood, but, I think, the pandemic relief made a lot people lazy and unwilling to get off the couch. Scarlet, now my partner in everything, has been my greatest blessing. When she can escape childcare duties she has proven to be the hardest worker I could wish for. I could use a few more workers like her: eager to learn, unafraid of dust and dirt and willing to sweat. She also manages all of the marketing, so give her the kudos for the web media you see. The business feels like it wants to grow so if anyone is seriously interested in building saunas and wants to relocate to Ithaca, drop me a line.
For those of you lucky enough to have a sauna, I hope you get to celebrate the New Year in it for there is no better way to bring in the new and shake out the old. It’s been my tradition for four decades now and I hope to continue for four more.
Taking Sauna with Scarlet by the Lake, December 2021.
Lately I have been thinking about the application of the foil I use in my saunas as a radiant vapor barrier. Perhaps this is because it almost Christmas and I was thinking of how we decorated the tree each year. The final touch would be to drape foil tinsel over everything; our mother would have to constantly damp down our enthusiasm by reminding us to place it carefully on each branch, not to throw it.
This suspicious “sauna” foil is Aluminum-coated Plastic—upper working temperature of only 55-120° C.
There are tricks to using the foil but the first and most important step is to buy the right stuff. Like the tinsel we put on the tree, the foil may actually be aluminum-coated plastic— which you don’t want to use. That plastic is likely polyethylene which, if you look it up on the material specification sheet that every product has, it has an upper working temperature of 55-120° C, meaning it will likely melt at typical sauna temps. Sauna Foil, available from any of the familiar sauna suppliers, is aluminum foil on a kraft paper backing. I used to find it with fiberglass reinforcing thread, which is helpful because the stuff tears easily. Also helpful is 4 ft. rolls, rather than 3 ft so you can do a wall in 2 passes, but I have trouble finding this too. I recently tried a new supplier selling 4 ft rolls of “sauna” foil, but upon opening it had a suspicious plastic look to it. That night I put it in the sauna and within seconds it began to distort and curl up like the polyethylene I suspected it was made of. (See illustration above)
The second thing is to design the wall correctly. I read and see a lot of misinformation that touts using no air gap with foil. The air gap is essential. The foil works by reflecting radiant heat. All “black bodies” give off and absorb radiant heat that travels in a straight line from one hotter object to another cooler one, the hotter the body, the more heat it emits. The sauna rocks radiate a “soft” heat to you, the walls, and the benches, and that is why you want the sauna to be laid out so that everyone has a view of the rocks. The fire, if seen through a clear glass door, also radiates heat— but at a higher intensity. Too high for a comfortable sauna (but great for ambiance.) When that heat hits foil, it is reflected back into the room or the backside of the cedar—if there is an air gap of at least 1/2″. If it touches the backside of the cedar the foil— also a perfect conductor—pulls the heat away from the cedar and transfers to the wall space behind.
Air Gap. A Sauna Building Best Practice.
I’ve understood this for along time. The first semester of college I took a class: Solar Design and the Energy Efficient Home. We learned all about insulation, heat transfer and basic building skills. The first day of lab, where we were building a timber frame house, I was handed a Makita 12″ circular saw. My building career started right then and there.
With the web of misinformation out there I had to think of a way to illustrate this basic principle of thermodynamics that I learned my freshman year. So, one slow day in the shop I rigged up an experiment and photographed it. (see illustration below) I set up a section of cedar wall about 18″ from my infrared shop heater and fastened 2 pieces of foil to the back, one with a 3/4″ air gap, and one with no gap. After an hour the cedar was 250°F on the front—like it is often is in my sauna. The back of the cedar was 121° F, which is impressive by itself. The back of the foil with no gap was 115°F, meaning it was acting as a perfect conductor, and the back of the foil with an air gap was 71°F: room temp. The air gap was clearly making a difference, 45° in this case.
The thermodynamic experiment begins.
After an hour on cedar
back of cedar
back of foil, no gap
air gap makes big difference!
The foil is a perfect vapor barrier rated at zero perms— meaning no vapor moves through it. But unless you layer it properly, with insulation behind it, the moisture will condense on it, or the first cold surface it hits. Even in a perfect build, there might be cold spots in the insulation (typically about the size of a mouse hole), so there likely be some condensation, but not a problem if there is air movement. The air gap behind the cedar allows air to circulate around the cedar, removing any moisture and ensuring that the wood heats and dries evenly and remains stable. Heating one side of a board and wetting or cooling the other is how you make curved boat staves.
There are other tricks to using the foil- like unrolling it and re-rolling it foil-in, or using temporary magnets when working a commercial job with metal studs, but the key is to use care. Use plenty of hi-temp foil tape and patch tears as you go and work with a partner if possible.
I suppose you could build a sauna by putting a heater in a refrigerator box- but that would last about a day and be incredibly wasteful. Cedar touching foil won’t ruin your sauna and neither will plastic melting in the walls where you don’t see it. But if you are going to take the time and bear the expense of building a sauna, you might as well do it right and so it will last generations. I guess my mother was right: applying foil carefully and not just throwing it up is the way to work.
Building a sauna requires many skills. Basically it is a small house; there are windows and doors, a roof and a foundation; framing, sheathing, subfloor, and the like. It also requires a design, and many cases, a permit, which will include drawings such as a site plan, showing required set backs and orientation. All of this I can do— from plans and permit applications to foundation to chimney. I pride my self on being able to do it all and to being as comfortable holding a drafting pencil ( yes, I do drawings old-school) as I am a pick-axe or nail-gun. But the truth is, sometimes it is best to let others do the work they do best so I can focus on what I do best, which is the sauna.
Recently I had a job where distance made it much more efficient for the owners to use a local contractor to build the shell while I did only the sauna interior and the overall design. It turned out that Tim and his crew were much more adept than me at not only building the shell but carefully replicating the trim details of the 150 year-old adjacent main house. By the time I got to the job site the interior was ready for my sauna work.
Just like everyone else during the pandemic, planning sessions happened on the web or via text; we only actually all met once. Despite that, or maybe because we weren’t in each other’s hair (a sauna is, after all, a very small space), things flowed very smoothly once we got over the scheduling speed bump caused by the pandemic-induced supply chain upheaval. The sauna sits perfectly between the historical architecture of the house and the modern look of a contemporary sauna. It was a team effort that paid off.
When building a sauna the first and possibly most important consideration is the location. With a wood-burning sauna, which is free from the tether of an electrical connection, it can be away from the house—not just for safety but also to create a separation from the electrical buzz of modern life. Simple and inexpensive solar options make it easy to provide needed lighting. It should have some of the comfort of home but be integrated into nature; near a body of water is always a good choice.
My latest sauna does all of that and more. The site is fairly close to the house but lies outside the garden gates. It all but hangs on the edge of a small gorge that contains a lively creek in its serpentine confines. Like the basswood and cherry trees that cling to the sides of the gorge, firmly rooted in the ground, the sauna is anchored to the 300 million year old shale bedrock with concrete and steel. The owners built a steep stair down to where small waterfall flows into a perfect bathtub sized hole. Descending it may be slightly perilous but that only adds to the adrenaline to rushing from the steaming of the sauna and plunging in the ever-cold water.
As I build I tweak my design to allow nature into the sauna. Framed and without sheathing I could see the perfect view up the ravine from the upper bench, suggesting the optimum location for a small candle window. The large window allows a view of the wooded hill and brings in ample afternoon light and the view down into the creek through the framing allowed me to imagine the possibility of a small square creek view porthole below knee level that would let in the ambient sound of the rushing creek. Exiting the sauna one faces the woods, not the house; a crude stair-path leads the eye up into the forest while the other leads to the creek.
The sauna is visible from the road and the house, but neither is evident from the sanctuary within. All you hear is the babble of the creek and all you feel is the relaxing heat of the sauna. Finishing a few rounds in the sauna with a dunk in the massaging water is pure bliss.
The site not only perfect for the sauna but it was a joy to work there, listening to and watching the water flow. Daily I took dips in the creek to beat the steamy summer heat. Having a site that allows me to enjoy the process of building lends means I can build a better sauna—one that is infused with the spirit of the place and connected to nature.
Increasingly I hear from clients who want their sauna as a way to enhance their hot yoga (Bikram) practice. It’s a perfect pairing: what better way to follow up (or warm up for) a yoga session than with an even hotter sauna!
Recently a couple asked me to convert an old dingy freestanding cinder block garage into a sauna/ hot yoga studio. First I made sure the cinderblock wall was stable and did some minimal repairs. Then I isolated the block wall from the warm, humid space by adhering expanded polystyrene (XPS) foam board to the walls. This is critical as it prevents moist air from hitting the cold cinder blocks and condensing. Then I framed in the space, insulated the walls with mineral wool batts and finished the yoga space with drywall and the sauna with cedar (with the requisite radiant sauna foil layer and air gap). New windows replaced the old; the dramatic deep window recesses a result of the thick walls. Bamboo flooring over floating sleepers over foam board created just the right bounce for the yoga space, while the sauna has traditional duck boards. LED lighting added just the right ambiance. The heart of the sauna is the Harvia Cilindro heater with it’s 200 pound rock capacity. Amazingly, the old building was plumb and square— the original masons did a good job. Fighting an out-of-square space is the bane of all renovators.
This project was a complete transformation for this building (see below), turning it from a creaky old, under-utilized garage into a revitalized space for self-transformation. Make an inventory of the neglected spaces on your property awaiting transformation and give me a call!
You’ve probably heard that I’ve spent a lot of time in the sauna but another hot spot I’ve spent a lot of time around is kilns. Specifically foundry kilns and ceramic kilns. Unsurprisingly there is a strong relationship between the two as they both involve getting things hot. In the lost wax casting process, investment or ceramic shell molds are heated to roughly 1500° F, which burns off the wax original- thus the “lost wax” of lost wax casting. This can take hours or even days depending on the mold type and size. A ceramic kiln can get much hotter- up to 3000° F. That is hot enough to melt steel and many other metals.
I learned how to do bronze casting in Art School. It is an ancient process and we did it pretty much the same way that it was done thousands of year ago. We learned to figure how hot things were by using our senses. All objects emit radiation when heated but at about 1100-1300° it become visible. Peering into a hot kiln (safety glasses strongly suggested) is like looking at another world, perhaps on some alien gaseous planet. Solid objects look like they are transparent. Heat and light become the same thing, the heated molds don’t reflect light but emit light. The blast of heat through the spy-hole is like a ray gun. We rarely used pyrometers (hi temp thermometers) and when we did it was only to affirm what our senses were telling us. We would record the smells of things burning off. When the smells were gone, the molds were clean and ready to accept the molten bronze.
When loading the kiln there is always discussion about the hot spots- certain delicate molds need to avoid the heat while larger molds might need it more. There is always conjecture about how the heat circulates; a whole aspect of kiln building is dedicated to controlling the flow of heat within the kiln. Some of this conjecture is borne out in the results of a firing—whether things fire correctly or not. Ceramicist use cones: small tapering forms that bend at specific temperatures. After a firing these will give a true telling of how the firing went. But, despite the science, there is still a lot of mystery and art to the process, so much so that a firing of a large kiln can take on a ritualistic feeling. Staying up late to tend the kiln, as is done with wood fired and other non-automated kilns, drinking beer and heating up pizza on the kiln, tends to add to the aura.
Thinking of all of this makes me think of sauna. Both have been done pretty the same way for millennia with an aura of ritual and involving community. Both have a focus on fire and heat, and, as well studied and commonly practiced as they both are, there is still a bit of mystery involved in each.
A kiln is like a sauna on steroids. The heat is so amplified that its flow and effects are unmistakable. Observing one is a lesson in thermodynamics. In the sauna building culture there is a lot of banter about how to best heat, insulate, and vent a sauna, yet all of it is conjecture based on theory until one sits in a sauna and feels the heat radiating off of the rocks and the wave of löyly hitting you on the sensitive tops of your ears.
When I design a sauna I draw from my years of kiln experience; I think of the heat as visceral substance, almost visible, as in a kiln. I relish the use of my senses to discern quality rather than depending on technology. Even if the sauna is electric with a digital control panel I rely on feel, not the number on the display. I imagine the flow of heat like the way it flows in a kiln. My foundry experience has informed my understanding of sauna in ways that are hard to describe but suffice it say that I have always been drawn to fire and to the mysteries that it holds.
COVID sure has made life strange and difficult for all of us. Patterns of living have been upended and new norms have emerged that will probably stay with us. One pattern that became very clear was that many people have decided to make their homes more livable, especially when it comes to outdoor spaces. Fortunately for me, this includes home saunas, which have seen a huge spike in demand which I am tying to keep up with. But, there has also been a huge increase in demand for materials associated with these types of projects causing me delays and headaches. Like the toilet paper that disappeared early in the pandemic, framing lumber, cedar, and pressure treated decking have all but vanished in some stores. Not only are people buying more for their home improvement projects but the triple whammy of last years wild fires, Covid taking out some of the workforce, and tariffs on Canadian lumber has caused major shortfalls and huge price increases in building supplies. Yesterday I bought a single sheet of OSB (oriented strand board— the most ubiquitous of building materials and the sheathing on virtually very house) and it cost me over $27—$20 more than what I paid 18 months ago. Everything else from 2×4’s to steel plate has doubled.
The contracting business depends a lot on giving a solid price well ahead of time so that the buyer can plan and budget. I’m working on projects I bid 6 months ago at prices I thought I could expect to pay when I got to the checkout. How can I give quotes when the prices are going up like that? Often, I have to eat those unexpected cost increases. Maybe the prices will fall, but I think, like wearing masks in grocery stores, we have hit a new norm.
I can’t absorb all this pricing mayhem so I’ll have to pass some of it on to you- my valued customer. If you are doing a DIY project and using a book written ten or more years ago, be sure to check prices; the big box stores do a pretty good job of posting it all online. And when you ask me how much something cost remember that cost, like time is a fleeting thing.
The most important thing to remember though is: how much is a sauna worth to you? It is measured not in dollars but in real value added to the quality of your life. In other words: priceless.
With over 30 years experience working in the building trade, Rob readily dispenses his knowledge to clients, a clear, professional communication style. If you need in-depth information on how to build your own sauna or need drawings/plans whether you are a builder, DIY builder or architectural firm I offer plans and consults. BOOK A CONSULT HERE >
Candle windows hark back to my time at Podunk where the light in the sauna came from a bare bulb in a porcelain fixture outside a little square window into the dressing room. The sauna i s too hot for a standard light fixture, so this arrangement made sense. Later, after I started building saunas, I learned that this was a more modern incarnation of the original candle window, which was literally a window into the dressing room with a shelf for a candle to sit on. These are common in Finland in freestanding saunas away from the house. The window allows for a special kind of spiritual, summoning light into the sauna. Especially on those dark winter nights.
In the sauna tradition, we slow down. The flickering candle light seen from the bench in the sauna, lures you to relax and reflect. Life and relativity. Could there be a more tranquil way to release the stresses of the day?
Although it is this quality of the light that is so important, the candle is totally pragmatic in a very Finnish way. A candle in the sauna room would melt even if not lit, so this was an obvious solution to the problem of lighting the dark interior of the hot room. Despite its pragmatic origins, I find it is also a chance for a little expressive design: it can be round or square, arched or colored. It can have an organic flare to it. Now, with cheap, battery-operated, multi colored LED lights and even fake candles that look real, the light can be more than a simple bulb on a pull-chain porcelain fixture, and be safe. Even if the sauna has built-in electric lighting, the candle window can be a signature element, one that distinguishes a personalized custom sauna from a generic kit.
It’s in the details.
Finnish pragmatic design inspiration comes from making use of what is available at hand and letting that material influence your design. There are many places to incorporate little details and personal touches: stick hardware towel pegs, stone faced stove wall with stones from your backyard, thresholds of locally cut locust, round windows, etc. Think of decorative elements you can hang above the mantle. In my sauna building plans you can purchase and download, there is more about windows, framing information as well as tips on using windows safely in mobile saunas.
wood burning sauna with candle window to dressing room
Here is a collection of the candle window design and builds over the years in and around the Finger Lakes and New York State.
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A lot of building science is pretty theoretical because, no matter how much research you do, at the end of the job most of the work is hidden in the walls. Unless you come back to do renovations, or worse, get a dreaded “call back” for something gone seriously wrong, you rarely get the opportunity to see how your work performs. I am not talking about cosmetic details like nail holes that don’t get filled or rough edges that didn’t get sanded, but about how well materials hold up to the heat or how well you have managed moisture movement through the walls, either as precipitation working its way in, or the more mysterious way that water vapor works its way out. (or inwards in some climates). This moisture is driven by vapor pressure, which can drive water molecules through most any material given the right humidity and heat differentials— something a sauna has a lot of. I learned about vapor pressure when I realized that my hollow steel yard sculptures were inexplicably filling up with water. My welds are very solid and water-tight but somehow moisture was penetrating the steel, condensing and not getting out. Cutting holes in the bottoms to let trapped water out solved that problem. There’s a bit of molecular science involved here, but suffice it say that vapor pressure is very strong- strong enough that when I throw water on the hot rocks my sauna door pops open as if the löyly has scared a ghost out of hiding. (Read previous post about Insulating Saunas)
Thinking about all of this has left me wondering what is happening in my sauna walls; am I doing a good job? is the insulation holding up? is water getting trapped?
Yesterday I had to do some retrofitting on the first mobile sauna I built in 2013. I exchanged the Scandia gas heater for a wood burner and got to peer into the dark interior of the walls. This is a sauna that has seen heavy and very hot (200°+) usage. The walls were built with cedar inside and out with only a 1″ layer of foil faced polyioscyanurate foam board in between the studs.
Here is what I found:
There was no damage from trapped moisture and the foam board looked as good as new; the foil facing still shiny! There was some high-temp fiber fax insulation used around the gas heater; a rodent had gotten into this (despite my filling gaps around the gas line with steel wool) and made a stinky little nest.
So this confirmed my use of the polyisocyanurate board, which has a service temperature of 250°F and my disdain of fiberglass type materials (because rodents love it).
polyisocyanurate board, original state
fiberfax mouse nest
Melted EXP (expanded polysytrene) foam
On my desk I have a piece of EXP (expanded polysytrene) foam I pulled out of a failed sauna I was asked to repair. It looks like one of my steel sculptures from my Landform series – a flowing, green landscape (of melted plastic). Its service temp is listed as 150° F. All materials have material data sheets, usually available on the manufacturers web pages. I consult these whenever I am unsure about materials, especially given that the extremes of the sauna are like the extremes NASA engineers have to deal with. Clearly there is a correlation between science and reality, even if it is happening unseen inside the walls of your sauna. So when choosing materials, listen to the science, learn from observation and don’t just buy the cheapest materials or use only the easiest approach. Consult with the experts. Sometimes there is more to it than meets the eye.
See more building science tips and pics on Instagram @SaunasByRob Facebook @customsaunas
The New England coast is beautiful and varied, from the dramatic rocky shores of Maine, to the sandy beaches of Cape Cod to the rocky moraine of Long Island’s north shore. The one thing New England’s coastal waters are not is warm. I remember swimming in Maine when I was in art school in Portland: I would get all hot and sweaty by running or biking to the beach, and jump in and swim a brisk few hundred yards to the astonishment of onlookers who dared not go in past their knees. For most people the swimming season in Maine consist of two weeks in August.
It is no wonder that my last several mobile saunas have found homes near the coast—what a perfect way to extend the swimming season! Cold water and saunas traditionally go together. Ideally the sauna is situated so one can plunge into a lake, pond, stream, or the ocean after each round. With a sauna on wheels you can pull up to your favorite dipping spot and indulge yourself anytime of year. There is nothing like the thrill of jumping through a hole in the ice or plunging next to waterfall in the whiteness of winter.
The mobile unit is fairly clandestine – once the stove reaches temperature the chimney smoke is invisible; no one will suspect you are nearly naked inside basking until you burst out and head for the water. I haven’t had the pleasure of sauna-ing next to the ocean but one of these days I’ll have to travel back to Higgin’s Beach in Maine, sauna in tow, and give onlookers as thrill as I defy the icy winter water with a post-sauna dip.
You ask how or why electric mobile? There are a number of reasons why going mobile makes sense, especially if you rent. You need no permits or special permissions. You just park it in your yard and use it. You can take it with you on vacations or just for a Saturday down by the lake, you can even enter it in a parade. But why electric? Electric is no longer the inefficient dark horse of the energy world that it once was. It can be generated cleanly by wind or solar and is cheaper, cleaner, and easier to use than gas or oil. Although any purist will tell you a wood-burning sauna is the real deal, in some places wood is not so easy-—firewood may be hard to come by and to difficult store, and your neighbors may too close for comfort or offended by the occasional whiff of smoke. Since I’ve eliminated gas burners from my repertoire (for reasons I won’t go into here) an electric mobile sauna is the next best thing. All you need is a place to plug it in.
When clients ask me to create a sauna they often push me to do things I might have never considered doing. I’ve been requested to make saunas in spaces I thought were too tiny, on trailers, deep in the woods next to a pond, or to convert a cheap shed or laundry room. The most recent project to leave the shop is an electric mobile sauna. The owner has a Tesla electric car so an electric sauna just seemed to make sense. She also wanted the benches to flip up so it could be a mobile hot-yoga studio. The colors were more of an emotional choice: I painted it Sea Reflections blue like the ocean, where she likes to swim all year, with a Bonfire Red door to beckon her into the warmth of its interior, and Vanilla Ice Cream trim because, well, who doesn’t like ice cream, especially after a sauna?
The how, is simple: an 8 KW heater with a standard RV type hook up and a fifty-foot very-heavy extension cord that connects to standard car charging port (or special outdoor outlet). This will also work in many campgrounds with RV hook-ups. In a pinch, it can also be run off an 8500-watt generator.
This sauna also has a solar powered low-voltage lighting system, just so there can always be light and because low voltage systems are safer and more versatile than 120 volt lighting. I’ve been using these in some mobile wood burners and freestanding units. The neat little solar panel is a conversation starter; people are suddenly aware that the unit is more than a fancy tool shed trailer. When I tell them it’s an electric sauna, the little 25 watt solar panel gets a second glance.
What I envision next (but probably won’t consider doing unless a client pushes me) is a fully solar electric sauna. It would have to use Tesla’s 270-pound Powerwall home battery, which has an 8kw output capacity. I imagine the entire sauna roof would a have to be a solar panel but I haven’t done the engineering on this. This would not be cheap, but if there is someone out there who wants to be the first…. give me a call…
The other evening I came home from work, stressed out about the Coronavirus, as many of us are, and decided to light the sauna to ease my anxiety. As it was a nice day, I decided to use the time it took the heat sauna to rake up those leaves that got matted into the lawn under a November snowfall. The breeze was out of the south which helped push the leaves into the hedgerow, but it also apparently helped fan the fire on my mobile wood- fired unit. By the time I put my rake down and stripped down for a relaxing sauna, the thermometer was pinned at 235 degrees! Not one to shy way from heat, I jumped on in anyhow.
Always inquisitive, I use such opportunities to add to my knowledge about the sauna. I wondered how hot different surfaces really were with the heat so high so, with only a towel on, I ran to the shop and grabbed my digital temperature gun. I use this gadget to test my saunas to make sure they are hot but also safe. The ceiling and walls were close to 300° near the stove, the walls were 230-250° above the bench, the benches were °200 and the lower benches were about 175°. The rocks were 450°- perfect for a good löyly- and the stove body glowing visibly red in the afternoon light, so about 1000° (the brightness of the glow corresponds to specific temperatures). The floor was predictably the coolest surface at 125°.
According to the Center for Disease Control, viruses cannot tolerate heat above about 167° F. Therefore, everything in a hot sauna from the lower bench up is guaranteed to be virus free! No fears or worries as I bask in the heat.
That being said, despite what we all wish, the sauna will not kill a virus that has already infected you, nor will it likely destroy a virus ejected in a sneeze. The sauna will not cure you or protect you if your sauna mates are sick; in these desperate times, it’s probably best to avoid group saunas with strangers. But, taking a regular sauna will lower your stress level, boost your immunity and help you sleep better- all in a virus free space. Maybe it’s time to think about having your own sauna so you can create your own virus-free and worry-free sanctuary.
Sauna is an interesting word. It is both the noun describing the little structures that I spend my days making and the action of how one uses that building. Mostly, I focus on the details of building and let the details of how one uses the Sauna fall to the individual taste of my clients. I don’t adhere to a dogmatic approach; everyone has his or her own experiences and memories to draw from. Different countries have subtle variations: wetter, drier, hotter, timed sessions, birch Vihta, etc. My memories stem from my time at Podunk, in the old Finnish Sauna. I remember the 5 gallon joint-compound buckets for gathering water from the creek, and the various cheap plastic wash tubs, brushes, loofa, and other bathing implements. There was some sort of ladle (which we always called a kipper in some mis-appropriation of Finnish-ness) for pouring water on the rocks. And there would be various soaps and shampoos–some common, some not so common, like the Finnish pine tar soap, which, despite its comparison to the sticky pine tar we would out on our skis, actually feels pretty good.
Podunk
Once the sauna got good and hot we would strip down as unceremoniously as possible and go in. The first round would always be pretty talkative and end with a healthy ladle-full or two of water on the hot rocks until we had to bolt out the door and head to the creek. If someone were annoyingly loud sometimes a good löyly would be timed so as to quiet things down. In the second and third round we might take great pleasure in thrashing each other (gently) with a birch vihta if someone bothered to make one from the birch tree outside the Podunk sauna. The old Finns would make them in the spring out of the fresh soft leaves and keep them in the freezer. Now you can actually buy them from Finland—dried and vacuum packed for a reasonable sum. After softening them in water for twenty minutes they smell just like a fresh birch tree.
The last round in the sauna
would be time to wash: after getting hot again we would take turns on the
little washing bench scrubbing ourselves (or each other) with the loofa or
stiff sauna brushes and some sauna soap. Finally a rinse with some warm water
would wash off all of that dead skin and residue of a week’s hard work and we
would leave the sauna all fresh sand natural smelling. None of us ever had to
wear deodorant or poufy colognes.
pouring water on the rocks
how to have a sauna “bath”
simple beauty of an ice lantern
Sometimes I sauna with friends, sometimes alone. Always it is the same: get hot until sweat just pours out of me, cool off, repeat; scrub my skin, maybe switch my back with the Vihta, wash up, rinse down the sauna. It’s a ritual of sorts but not like the way a ritual in the church is dictated to you. As in church, there are ritual objects that create focus help and direct the actions, but instead of incense and gold, they are plastic and wood. And unlike church, there is no sin in doing it anyway you want to. The brushes, basins, ladle, soap, and vihta are there just to help establish the flow of the sauna experience. To the uninitiated it may seem all strange, but after a few times, it all makes sense. It is just a bath house, after all.
Lately, I have found that the top of my noggin does not have so much insulation from the heat of a good löyly so I have taken to wearing a felt sauna hat, which is sort of like a Shriner’s Fez, which is to say that it makes you feel just a little goofy. But, then again, I wouldn’t want to be accused of taking the sauna ritual too seriously!
I just completed this bright blue, yellow and white gem of a sauna situated on a red deck. The color was the client’s choice; he wanted something that would brighten things up and be in stark contrast with usual suspects of taupe, dull brown, and moldy blues that afflict his neighborhood and so many other American housing developments. Why are builders so afraid of color?
The use of bright color in homes is often associated with places like seaside Baltic towns and Reykjavíc, Iceland—and for good reason. In the deep of winter these places are plunged into darkness as the sun hovers near the horizon or barely makes an appearance at all. Battling the winter blues should make the use of bright colors almost mandatory. Of course these places all have saunas too (or in the case of Reykjavíc, massive public hot springs), another way to survive the depth of winter. I also learned, when I was an artist-in-residence in Nova Scotia, that fishermen traditionally used bright colors in their houses simply because it’s left-over boat paint. Boats are painted brightly so they can be uniquely identified at sea, so, in a way, the colors express something unique about the individuals who live in there. Now, of course, the brightly colored fishing village is almost a tourist mandate.
Looking back on recent sauna projects, I see a shifting trend in color choices made by my clients. From authentic dark brown Viking tar, to blue-grey, then, brighter reds and blues and greens, and now, this latest color feast. There is also a trend in design to use more bright colors such as on the running shoes I saw in the gym yesterday that were an eye-popping florescent orange. I have been following the designer Ingrid Fetell Lee who writes about creating joy with color in her book The Aesthetics of Joy. She is persuasive about using more color for the simple reason that it creates joy. Although I teach color theory, I have a tendency to stick to blacks, grays and low intensity colors in my art, a trend that I have been to trying evolve out of. Perhaps I can take some cues from my clients and take some color risks in my own work. This latest sauna project actually makes me think of a late Mondrian painting such as Broadway Boogie Woogie in which he reduced his palette to the three primary colors and sought to use color as the basis for expression.
In this latest sauna project my interest in sauna and art actually converged. The warm interior heats your body and the colorful exterior warms your spirit. Thanks, Karl!
I just completed a large (9×12 foot ) sauna at Silverlaken Glampground near Letchworth State Park. This is such an ideal setting for quiet retreats or group gatherings: a main lodge in a historic cottage, private cabins and luxury tents next to sparkling Silver Lake just miles from one of the most popular state parks in New York. The sauna is the perfect centerpiece for small or large gatherings. A group sauna is different than a small intimate home sauna; it is a unique social situation where you may commune with strangers and make new friends all while stripped bare of the trappings of social status, class or superficiality. It can be a perfect setting for friends to solemnly celebrate life’s important moments: a reunion, a wedding, a men’s retreat or whatever occasion that will be enhanced by closeness and shared exhilaration. The sauna easily holds a dozen or more bathers and is a stone’s throw from the lake.
As I always do, I tested the sauna before leaving a finished project. The new owner was elated as a I brought it up to temperature while I explained the intricacies of sauna; after a round we jumped in the brisk lake. It was the perfect way to end an exhausting effort and make my long haul home a relaxing one.
If you are in Western New York and looking for a unique place to stay and want a sauna experience, I recommend you checkSilverlakenout! (listed on Airbnb)
The Kiuas, or heater, is the heart of the sauna. In a wood-burner, it is commonly referred to as the sauna stove, but a wood stove it is not! There is a lot of misconception around the kiuas and how it is different from a wood stove that you might use in your house.
First, some history. The modern house stove is really a heating device designed to add comfort to your home while conforming to certain safety and smoke emission rules. Typically they are not used as primary heating appliances, unless you live in a cabin off-grid somewhere. Back in 70’s, during the energy crisis, woodstoves become popular as a way to save money. They were pretty much unregulated and varied in design from a kit that consisted of a door and a flue collar you could slap onto a used fifty-gallon drum, to a more complex Vermont Castings wood stove. Earlier stoves had little control over combustion; these evolved into airtight units that could keep a smoldering fire all night, if not for an entire season. I had one of these and didn’t let the fire go out all winter except to clean it. Cleaning the chimneys on these was imperative: when wood—especially if it is not cured for two years— is burned slowly by reducing the combustion air to near nil, creosote forms as the result of the resinous gasses condensing on inside of the cool chimney walls. As a result of the slow burning, these stoves emitted a lot of smoke. After many houses were lost to chimney fires, safety regulations were put into place and stoves were required to use catalytic converters, much like on your car, that reduced emissions. These required a religious adherence to the use of dry wood, lest your catalytic converter clogged up, which most of them did. Those evolved into today’s stoves that use a carefully designed system of baffles and airflow to make stoves burn efficiently. Now, all wood burning home heating device installed in the US must comply with UL (Underwriters Laboratory) safety standards and increasingly stringent EPA standards for particulate emissions. The stoves work well and are very cozy but, by design, they don’t get very hot fast, nor are they meant to burn all night long, not to mention all season long. Because they are intricate with interconnected parts, they are all cast iron. The exception is some stoves made in the pre- catalytic converter era, which were welded steel.
So, that is a wood stove. You may find a used one and think you can build a sauna around it, but the truth is, with the rare exception of one of those 70’s all welded steel (but not a barrel!) stoves, you can’t. You can build a small hot room with a wood stove, but it will never be a real sauna; here is why: A sauna stove, or kiuas, is designed to do one thing: heat sauna rocks. It is the hot rocks that heat the sauna, that produce the burst of löyly steam and that are true heart of the sauna. Early saunas did not have a metal stove- they did not even have the technology to make a metal stove- all they had was wood, earth and rocks. The kiuas was essentially a hollowed out a pile of rocks. The fire was lit within, the room filled with smoke, and, after the rocks got hot, the fire was extinguished and the room cleared of smoke and then the rocks heated the room. The closer you can get to that smoke or Savusauna experience, the better.
A sauna stove is not a wood stove; it fires hot and fast, it burns sticks, not logs. It’s job is to heat rocks. If fired correctly, you will never have to clean the chimney- a hot fire will combust all of the sticky wood gas. It is welded steel—which can have water poured over it while red-hot. Cast iron cracks or explodes when subjected to this. It can take the weight of a hundred or more pounds of rocks sitting on top of it when cherry red. Ferrous metal takes on specific color when heated; at 1400° F. it is cherry red. At that temperature, an 1/8 inch plate of steel is as malleable as taffy on a hot summer day at the beach. I repaired many sauna stoves where the top looked like an egg carton from the stones pressing down on the hot metal, so I started making stoves with half-inch thick plate at the top. I fire my stove so hot that I see dark cherry red glowing underneath the stones. If you fired your home heating wood stove like that, you would be crazy. I swear that sometimes I could read a book by the glow coming off of my sauna stove. I like to push the limits so that I know it is safe.
When you light a sauna stove, you want to fire it, that is, to bring it up to temperature quickly. Use paper and dry kindling and then stuff it full of sticks, not logs (wood scraps from building saunas work great). Because they are for intermittent use, they are exempt from the EPA particulate rules but, the truth is, once it gets going—after about ten minutes—it should burn so hot that there is no smoke at all. Other than the shimmering light from the heat, I can’t tell my sauna is heating up by looking at the chimney. House woodstoves are tame devices, meant to be safe. Sauna heaters are another beast; that is why I will never install a wood burning kiuas in a sauna in or attached to a house. They do burn down now and then.
If you are building your own wood-burning sauna, you may have a building inspector involved or have to get a wood burning appliance inspection for your home insurance and that may require a UL listing. The only heater with UL label on it is the Lamppa Kuuma stove; most of the others are made for the European or Canadian market, which uses different standards, so before you click on “buy” you should have a conversation with any inspectors involved. They may love the idea of a sauna or they may think you are crazy to sit in a small hot room and throw water on a red- hot wood stove, in which case you’ll have to convince them that it’s something that’s been done millions of times without incident. In any case you will need to make a safe installation of your Kiuas – there are clearances and heat shields and floor hearths; none of these can be cheated on, unless you don’t mind owning one of the ones that burns down. There is also combustion air to consider- which is why I like to fire mine from the outside. The sauna stove sucks up fuel and oxygen, better to not be sucking the air out of the tiny room you and your friends will be in. Not such a problem with a house wood stove (but with newer air tight construction and tiny homes, it is).
So, before you get that old woodstove you find on Craigslist, do your research and think about investing in a real sauna stove because the kiuas is the heart of the sauna and the kiuas is not a wood stove!
My stove pipe will get cherry red!
After ten minutes, a hot fire fire should burn clean and smoke-less
All stoves will smoke initially
Nothing bigger than arm your arm!
This armload of ash (the wood) will fire the sauna
Fill it and let it burn hot before closing the ash drawer
My latest mobile sauna project started when a customer contacted me wanting a mobile sauna she could use for hot yoga. It’s my standard five by eight foot trailer sauna but without the benches. The arched roof allows for plenty of room for stretching out and the floor is soft cedar. The heat comes from a Scandia propane-fired heater. It’s a cute little unit that weighs under 2000 pounds. Tow it to the next yoga retreat and show off your downward facing dog
When the client for my latest mobile sauna project contacted me, he told me he needed something that would look and feel like a sauna from back home in Finland. He wanted it to be wood-fired and to get really hot. He wanted the clean lines and rustic charm of Finnish design and even requested a traditional pine tar finish like what the Vikings used on their boats. As small as it was to be, it was to have the standard two rooms- the sauna room and a dressing room. He also wanted to use the latest solar technology to light it with a soft glow.
But, working for an American company, where he might get moved from time to time, he wanted it to be un-tethered to his house, to be portable so he could always bring it with him, like a cherished possession.
I enjoy challenges–in fact, I thrive on them. One of the advantages of having my own company is that I get to decide how much to put into each project and which projects to really focus on. On some projects, like this one, I get to expand my repertoire. The goal, as always, was to bring my client’s dreams into reality. The result: a mobile sauna on a 81 by 120 inch trailer, under 3000 pounds, with two rooms, solar powered lighting, custom wood stove, northern white cedar interior, and pine tar exterior finish, did just that. I created a little oasis— a reminder of Finland—to park in his back yard, a dream come true.
Saunas are like that. When you have your own, it is a dream come true, a special place to escape into, to relax and unwind. It is tied to old traditions but for many, it is a new experience and can be life-changing. As designer and builder I get to be the midwife for people’s dreams and help them usher in a new way of living or rekindle a past love. As we turn the page to a new year and think about resolutions, what dreams do you want to come true?
mobile sauna by rob licht Custom SaunasSolar powered lights on mobile sauna by Rob Licht Custom Saunas
I get a lot of questions regarding sauna insulating details and thought I’d shed some light on a few issues. A caveat before I start: heat transfer science gets pretty complicated and I am grossly simplifying things here. I’m not an engineer but I rely on experience and am constantly probing and measuring my own saunas to see what works. A building inspector may want an engineer’s input, but just make sure the engineer understands what happens in a sauna.
If you are building an electric sauna, either in your house or as a stand-alone building, you’ll naturally want to insulate it for efficiency. Normally builders (and building inspectors) think of R-value (printed on every insulation product label) as the golden metric, and the R- values of a wall assembly are typically added up to get a number that either complies with code or satisfies a self imposed trade-off between cost, efficiency and practicality. R Value is the resistance to heat transfer but measures conduction and convection, not radiation, which is not much of a factor at lower temperature differentials. R values are calculated with normal living spaces and long term heat retention in mind, which in a typical home is calculated using an average temperature differential of 24°C (between heated and outside space). Since R= Delta T/ QA , (where QA is the ability of the material to transfer heat) and in a hot sauna Delta T might be 100°C, the use of labeled R factors is totally skewed!
The second factor is time. Heat loss is measured in BTU/ hr. With the sauna only on for few hours a week (bravo if it’s more!) your heat loss will be minimal and hopefully, in the cold months, will contribute to heating the house. So, in terms of cost vs. efficiency, a lot of insulation may be over kill.
At the higher temps of the sauna, the radiant effect of heat is more of a factor and the use of a radiant foil barrier comes into play. The heat you feel radiating from a wood stove is the long wave radiation. This radiation can move through common building materials but foil stops it dead in it’s tracks. Anyone who has nestled under an emergency blanket or protected himself from the fiery of a blast furnace, like when I pour bronze, understands the effectiveness of foil to bounce radiation back towards the heat source. But if the heat source contacts the foil layer, the aluminum superbly conducts the heat, defeating the purpose. So, when building a sauna, it is the radiant foil layer, with an air gap (on the hot side) that is crucial to holding the heat in. This should be backed by as much standard insulation as is practical, but don’t worry about attaining super R – value. The exception being if the wall is an outside wall of the house and a part of the building envelope- then, R-value must be a minimum of what the rest of the house has. I prefer Mineral wool, but in any case do not use XPS or EPS foam directly behind the foil, as they will melt at sauna temps!
Vapor control in an interior sauna is really important especially in modern tight houses, which tend to trap moisture, both for the damage vapor can cause that you can see, such as peeling paint, but more for the damage you won’t see, like moisture condensing in a wall cavity. Radiant foil barrier, when carefully taped at the seams, is also a perfect vapor barrier. When I build interior saunas I think about all of that moisture and imagine where it can get to and wreak havoc. I then seal off those spaces but provide a vented path for it to escape. Some enthusiastic löyly action will turn ladles of water into steam which fills the sauna but then escapes into the house— like when you forget a kettle on the stove and all your windows fog up. The best thing is to build your sauna next to a shower area and then vent that area with a decent bath fan to the outside or via the household HRV system. The sauna should then have an air intake under the heater as per manufacturer’s instructions and via a gap under the door so sauna gets a healthy exchange of fresh air. Never connect the sauna directly to a mechanical ventilation system.
With careful planning of layout, insulation, ventilation moisture control, and a heater that makes good löyly, your indoor electric sauna can feel like a wood burner on a pond’s edge but also be an integral part of your efficient home. (Read more about Sauna foam and best sauna building materials at Sauna Insulation, Revisited)
Sauna is all about perfection. Not over-the-top polished perfection, but a perfect way of being: simple, pure, functional; perfect living. Harmonious. After all, you enter the sauna naked, our perfectly imperfect bodies exposed but hidden in the dim light. You sweat out the toxins of life and leave with a clean aura. Like the Japanese concept of Wabi-Sabi, the sauna encourages acceptance of the imperfect as natural and beautiful.
When I work on my saunas I am constantly aware of this. Too much perfection will ruin the relaxed atmosphere; too many crisp details will hold tension in the materials. I relax when I work, become one with my materials and try to imbue the building with a human inexactness.
It’s all made by hand or by nature: the pulls on the doors (hickory branches), the handle on the stove (me, wrapping stainless rod—like wrestling a snake); the benches (massaged with sand paper) and the funny round window (imperfectly round like the eye of a whale). The stone facing on the wall around the stove was pulled from a hundred-and-fifty year old barn foundation and carefully split with whacks from the hammer my great grandfather used to carve head-stones. The dressing room floor: reclaimed fir, every bit as tough as the day the trees were felled. I use some new materials but never looking like I just pulled them off the shelf in some big box store.
I’ve touched it all many times—each board, each stone, each piece of metal. I carry slivers of each project in my hands for weeks—a constant reminder of the work I do. I think of our physical world built by hands. Every brick in every building handled, touched and in the memory of some callus; everything we think of as solid and real created by someone’s toil. Even the rocks that mark the hedgerow at the back of the sauna were placed by hand almost two centuries ago; the sweat of that farmer’s labor infused with this thick clay soil.
This last project was nearly perfect—which is as close to perfect as I want it to be. Great client, perfect site, easy access, and nice new pond with a beautiful dock and deck. Ok, I did order the wrong color roof but the multiple drives back and forth to Mid Lakes Metal, down the spine of the ridge between the lakes was perfect. With my windows wide open, I could taste the salt of the earth and was reminded of why I call this place home.
All summer long I have eagerly anticipated this week; we have a cottage rental on the lake. It’s the highlight of my summer and a much-needed break from all of the projects I have going on. This year, in addition to the usual activities—swimming, canoeing, beach fires, collecting beach glass and just staring the waves while sipping wine—I’ve added one more: sauna! I’ve brought my wood-fired trailer sauna with me and parked it ten feet from the water’s edge. Nothing beats coming out from the hot steam of a good löyly and jumping into the cool, refreshing lake. It is perfection.
Mobile Sauna by Rob Licht Custom Saunas on Cayuga Lake
My good friend Daniel has come home for a few days so we decided to take the trailer sauna down to Podunk, his family’s homestead, where, as a youth, I was indoctrinated in the way of the sauna. The old shack built by the original Finnish owner of the property has long since gone to the squirrels, but our memories of saunaing on cool summer evenings are still as vivid as the lush green canopies of the giant poplar trees that stand as sentinels in the field by the riverbank, keeping the creek from advancing any further as it swishes across the valley. On a geologic scale, the creek— the same that carved the falls at Taughannock— slithers like a snake, back and forth, carving a new path every few years. In our short lives we can remember when it made this turn or that, turning a rocky bank into an inviting swim hole or turning the old dipping spot—the one we would run down to from that old sauna, hooting and hollering— into a rocky shallow.
There is a new swim hole now. It’s an Olympic sized pool compared to what we used to dip in, allowing for real swimming as opposed to the slow rolls we used to take in the knee deep water just below where the pipeline crosses. As we lay there with our heads pulsing from the effect we called “sauna stoned,” minnows would nibble on our fresh cooked skin. With this new hole, the creek is more perfect for a sauna now than it was then.
I parked the trailer just on the edge of the bank and fired it up. The fact it was close to the creek where the spring high water often lapped the trunks of the poplars did not matter; this was a temporary affair, a brief encounter with our own youth, a dip into the pool of nostalgia. Once it was hot we climbed aboard and were transported back in time some forty years. My little stove holds a hundred pounds of rocks, all glacial erratics, transported here by the great river of ice in a time before memory. When heated, those rocks are capable of producing the best löyly, letting off a burst of steam that sends us out the door and clambering down the banks to the sweet cool water of the creek. It’s impossible not to let out a few whoops.
As a respite to the maddening distractions and over-stimulation of our times, people often seek out “authentic” experiences. There is often an understated desire to eschew technology and the associated flotsam that pollutes our memories of a simpler time. We laugh when we try to remember when phones were attached to the wall and being accessible meant you checked your answering machine only once a day. Life was slower and I don’t think there is anyone over 40 who can’t appreciate that. As far as traditions go, not much can beat the sauna, which has a 2000-plus year history.
Often, clients come to me seeking some sort of authentic experience—often tied to some childhood sauna at a summer lake-house or a weekly family ritual. They don’t want just an ordinary gym or hotel sauna; they want something deeper and more profound, something central to this notion of life slowing down. I imagine Sauna as a slow moving cinematic experience that is the complete antithesis to Godfrey Reggio’s Koyaanisqatsi film about life out of balance. In the sauna, the heat should melt not only the bodily stress of the day but also the sense of time itself. To be authentic, the experience should not follow a prescribed formula but be should simply be what naturally evolves in a Zen-like way of intentional non-intention.
What evolves naturally depends upon the built environment. Like cathedrals, which were designed to encourage spirituality, I build my saunas to encourage contemplation. It’s not just the temperature of the room, but the details that your hand or eye will settle on. The arched roof, view out the window and selected grain of the boards provide visual distraction so your mind can settle into the experience while your body adjusts to the heat. The surfaces, sounds and smells of the sauna are meant to awaken your senses.
When I am in the sauna I think about this, but I also try to think about nothing! I simply do what comes naturally- sweat, pour water on the rocks, cool down, look at the night sky, repeat, and then wash up. There is no magical order to the ritual, no rules to adhere to; the point is to create your own. I cannot create for my clients an authentic experience, but I can provide the catalyst in the form of a little magical space.
I’m excited about my latest project: a woodburning mobile sauna.
Unlike all of my other projects, which I design and build to meet the needs of my customers, this one is for myself. Over the past five years, I have been without my own sauna. It’s a long story: basically, I sold my house (and sauna) expecting to buy another and build a new sauna, but because the lending rules changed after the housing crisis, with a bias against self-employed folks, I have been stuck in renter’s hell. So, while my customers have been basking in the warmth of my creations, I have been languishing in a sauna-less purgatory, dependent on the generosity of my clients for the too-infrequent sauna. Like the proverbial cobbler whose kids have no shoes, I have been the sauna builder without my own. For renters like myself, the mobile sauna is the perfect solution.
It is a 5×8 sauna built onto to a commercial utility trailer. It is lined with northern white cedar and fired by one of my custom Lämpimämpi wood stoves. It has an arched roof using laminated bent cedar supports and aluminum sheet. It feels a lot roomier inside than you would think and comfortably holds 4 people. And, yes, it meets the 2,000 pound gross vehicle weight restriction of the trailer so it doesn’t require a huge truck to haul it.
I’ll use this sauna for promotion—look for it at various venues, festivals, including the Ithaca Festival parade (again! with our first appearance of a mobile sauna back in 2014). I’ll be taking this one with me on vacation or to my favorite park or forest stop. So, if you see it, feel free to stop and ask me to show it to you. Who knows, if it is hot I might even have a few spare towels.
The heart of the sauna is the stove, heater, or as the Finns call it, the kiuas. The role of the kiuas is to heat the room. Not like a wood stove, but to heat the sauna rocks, which, in turn, provide the heat and the löyly or steam that make a sauna what it is. In the savusauna, or smoke sauna, which arguably, offers the most authentic experience, there is neither stove nor chimney. There is simply a pile of rocks made into a hearth. A fire is burned within until the rocks are hot (filling the room with smoke) and then, once the fire is extinguished and the room cleared of smoke, the pile of rocks does its thing. Likewise, any sauna, whether it is wood fired or electric, is only ready when the rocks are hot.
When building a sauna, the heater is important. But the rocks are even more important. A good heater will hold a hundred pounds, thus, make good löyly. A cheap heater will provide a few decorative stones and you will feel like you are sitting in an electric oven. I have seen many well-designed saunas in my years and I have seen many poorly built saunas, as well. The worst use some variant of a cheap wood-burning stove with a dented pot of rubble or brick on top. In the best, the rocks are the focal point and they get red-hot. Pick one up and drop it into a pot of water and you can make tea.
Left: Rocks Shipped thousands of miles—only to explode in the sauna! Right: Cayuga Lake beach stones— can you spot the erratics?
The type of rock is critical: they should be igneous in origin, formed deep in the hot earth or in the furnace of a volcano. Think of these rocks as heat loving. Granite, grabbro and basalt are typical examples. The Finnish and Swedish units might use grey peridotite. Then there is shape: smooth and round potato shaped rocks or jagged and broken pieces. I prefer the smoother rocks, but there is argument for using the jagged (more surface area). You can order a box of the latter from Tylö that will come all the way from Sweden. Once I opened a box to find a nice hand written note from the fellow who packed them. Another heater company sent me a box from their supplier in Central America. Apparently they needed a geology lesson. The polished siltstone rocks, once heated, started exploding! If you don’t want to have a box of rocks shipped half way around the world or risk getting impaled by rock shards, you can try to find your own.
Unfortunately, our local stone, meaning the rock that is cemented to the landscape here in Central New York, makes horrible sauna rocks. It is all sedimentary: shale, limestone and sandstone. Born in the bottom of ancient oceans, it does not love fire and will complain by exploding if thrown into one. By the way, baptism by fire is a good way to test your rocks if geology eludes you—a good rock will happily glow red-hot. Thankfully, the glaciers that plowed through here brought with them piles of stone from places north that serve the sauna well. These are glacial erratics. As the glaciers retreated and melted, these stones were left behind. The resulting floods that carved our landscape left piles of these smoothed rocks (mixed in with plenty of local stone) in deltas, drumlins or moraines. I find them in the local gravel pit, which mines an ancient delta, or along the lake at my favorite park (another delta) when the water is low. Sometimes I take milk crates with me when I travel through the Adirondacks and fill them with potato-sized anorthosite rocks—which is what the moon is made of—and other pretty granites.
More important than the geology is the significance of the rocks. A Finn, even if they are using a heater with rocks packed in Sweden, will add a spirit stone or two: stones that come from home or some other special place. Stones all have distinct place markers and are borne of this earth and tied to a particular landscape. Except erratics—these have been swept from their homes in a geologic diaspora and found new homes as immigrants, oddities and beautiful accents against the dull grey of the indigenous rocks. Even though I am made of local stone, coming from generations of Central New Yorkers, I have always related to the erratics: the outsiders, the immigrants, the atypical people. They bring us diversity, new culture and traditions like the sauna. In my next sauna you will certainly find plenty of erractics.
Red Hot Adirondack rocks / My Lämpimämpi stove / Stove wall faced with local field stone including shale.
Finishing a job is always a sweet endeavor. I usually budget in one day of fussiness—a day when I can pay attention to all of the little details, get the stove in place and then, as a last step, give the sauna a test run. This is when I get to see how my efforts have paid off and take note of how the sauna actually fires. Is it hot enough? Is it light and airy and does it have that right sauna “feng shui”? Does it reach a good temperature and would Ozzie, the Finn who started me on my sauna-building path, approve.
The job I just finished is a modest affair: bare bones in that Finnish sort of pragmatism. I converted a kit-built garden shed, the type you’ll find parked on the edge of a big box home store parking lot, into a simple sauna with no dressing room. I liked the challenge of working within a modest budget, and I liked the folks: down-to-earth modern day Helen and Scott Nearing types. I had to remind myself that a sauna does not have to be a luxury item, affordable only by those in the higher income brackets, but that a sauna should be essential and ubiquitous as indoor plumbing.
I lined the inside with knotty pine—a low budget alternative to cedar. Sitting on the top bench I noted that the smell of pine reminds me of my forays into woods here in the east and is a close and familiar smell—unlike the rarefied smell of cedar. Aside from the knots, which will bleed sap forever and inevitably find it’s way into someone’s hair, it is a fine wood to use. It is not as stable as cedar but the inevitable cracks will open the sauna up and let it breathe. We always said that Ozzie’s old sauna at Podunk, with its gappy knotty pine walls and sagging ceiling, felt better than any other.
MyLämpimämpi stove fired fast and hot. The rocks quickly reached good löyly temperature and the first splash of water had me moaning in ecstasy. At no point did I feel that claustrophobic locker-room-sauna feeling of not being able to breathe. The dual windows filled the space with light. The benches will hold the couple, their kids and several neighbors. In term of the essentials, it is a perfect sauna. Nothing more is needed– no fancy tile work, no dressing room, no fancy cedar trim work. It works, plain and simple, and it works well. It was the best sweat I’d had in a while and a good sweat is almost payment enough.
For those of you who want to build your own sauna, I will be teaming up with Maria Maria Klemperer-Johnson, founder of the Hammerstone School for a week long sauna building workshop in September. We will cover theory and practice, focusing on all of the details that go into making a sauna. We will work on a pre-framed structure, finishing out the interior. I’ll teach about the design details like what wood to use, proper ventilation and fire codes and we’ll make everything from doors and windows to benches. The finished 8×12 foot sauna will be for sale when the class is over.
The class runs from September 5-10 and will be held at Maria’s school in Trumansburg, NY. This class is open to any gender and is especially suited for couples who want to make a sauna — and the experience of building their own — a part of their lives.
The one thing that always comes up when people ask me questions about building saunas is: how do you insulate it? Intuitively, one might think that the sauna, with it’s high temperatures, would need more insulation than a house and should be as tight as possible to conserve energy. In fact, I’ve had building inspectors give me a confused list of requirements using such logic. The reality is that a sauna is such a different beast than a living space that most of the calculations have to be thrown out the window. R-value, the number printed on most insulation products, is the resistance to heat flow of a given material for a given thickness for a given temperature difference (delta T) between the hot and cold side of the material. Typically, in our region, delta T is assumed to be 35° but, in a sauna, the delta T might be 165 degrees Fahrenheit! So, in terms of heat loss, we get some very different calculations! To really understand R-value, you need to think in terms of it’s inverse: the U value, or coefficient of heat transmission. U value is expressed in units of Btu/hr/sq. ft./°F, or, plainly, how much heat is lost per square foot for every 1° temperature difference. A typical sauna, with R-13 average insulation, might lose 4000 Btus per hour (or 1200 watts). But, A typical sauna stove generates 25-40,000 btus of heat per hour, so losing 4000 btu’s is not a big deal. (It is more important if you use an electric heater: an 8 kw unit, can only put off about 20,000 btus in an hour.) The other factor to consider is that, unlike a living space, you are not trying to hold the heat for very long. So, you don’t need to stack up piles of insulation in the walls and ceiling. In fact, many old saunas had no insulation at all.
What R factor does not measure though, is radiant heat flow. Radiant heat is like the sun warming your face; it is the short wave radiation that you feel. At higher temperatures, short wave radiation becomes a bigger factor than convection. To contain that radiant heat, we use foil, (think: thermos bottle or emergency blanket) but foil, being highly conductive, only works if there is an air space between it and the heat source. The foil doesn’t have to be visible to work; it can be buried between other layers of materials. In my Saunas, it is behind the cedar, with an air gap.
Saunas are also not meant to be tight, stuffy boxes. They require airflow to move the heated air and steam and to make them comfortable. The old Sauna at Podunk was the best one around because it was old and drafty and it always smelled fresh. Counter to today’s high tech homes, ventilation has to be has designed into the sauna room to let it breath passively; the trick is to do it without creating annoying drafts.
When you sit on the bench and enjoy the relaxing warmth of the sauna, you probably aren’t running all of these calculations through your head- and neither am I! What I do know, from 40 years of sauna experience, is what does and doesn’t work. Mostly, you want a good pile of rocks (kiuaskivet) that are hot enough to alternately bask you in their radiant heat and make good steam (löyly) and convective heat off of the heater (kiuas) to produce waves of heat that gently wash over you as you breathe in the fresh aroma of the sauna. You want air, some light and a feeling of openness and connection to the outdoors. It’s not so much science, as it is art, or perhaps a melding of the two.
If you do have specific questions about designing your own sauna, feel free to give me a call or email. Or better, have me come over for a consult. If you live far away, I can even do one-hour phone or Skype consults. In the future, look for classes I’ll be offering on Sauna building, where I can go over all the science—and art—of Saunas in greater detail.
Recently, I was called upon by a couple who had bought a property with an existing sauna that needed some professional help. The structure was a cordwood affair: a building method where timber framed walls are in-filled with short logs, stacked like firewood, with mortar between them. It looked like it came right out of the pages of Rob Roy’s classic how-to book: The Sauna. The exterior was fairly solid and quaint in a hobbit kind of way, but the interior, in terms of functionality, had some serious flaws. The timber frame and log and mortar walls looked pretty good, but it is obvious that the project was a classic DIY affair: a case of a homeowner taking on a project that looks easy, but with complex details that get skipped due to a lack of knowledge, funds or basic skill.
There are elements to a sauna that are essential: such as a welded steel stove that will not crack or explode when doused with water and the installation of that stove that conforms to the NFPA 311 guidelines. Insulation must be able take the heat, provide proper moisture retention, not attract rodents and not become a health hazard. Doors must open out and have non metal, non-latching hardware and be self closing (ever try to turn a 200° doorknob with sweaty hands?) There must be no varnish or paint in the sauna room; it will only off gas or worse, burn.
This sauna missed all of these points and more. From the pile of starling skeletons in the stove, I can only guess that it has not been used in a very long time (another detail: birds will fly down the chimney only to find themselves in a death trap.) From the lack of tell-tale scorching or smoking of the wood, I could also tell it had not had been used much. In fact, if it had been fired to a decent, Finnish-approved temperature, I am sure it would have either caught on fire or sent it users scrambling to get out as all of the varnished wood off-gassed.
It is a classic example of a DIY affair: started with good intentions but never finished properly. When I went into the house with the owners to discuss my plans for bringing it back to life, they brought out a book that had been left with the house: a dog eared and highlighted copy of Rob Roy’s: The Sauna.
I just completed my second mobile sauna for a client and brought it home to give it a test run.
The premise is simple: take a small trailer and build a sauna right into it so the client can move it back and forth between his lake house and his regular house. As simple as it sounds, the challenges to pulling off such a project are many. First, creating a roomy design into a five by eight space without creating a claustrophobic box takes some planning. A big window with a generous view really helps. So does the gently arched roof which means that even a tall person doesn’t have to stoop. And the white cedar I use creates a world of it’s own: entering the sauna, you are bathed in the aroma of the north woods. The color and gentle pattern of the grain is soft and welcoming to the eyes. It is really this cedar, which I get from northern Vermont, that makes this little vessel possible: it is the lightest North American species, yet no weakling. Favored by boat builders, it is easy to bend, strong and stable; it allows me to keep the trailer under its listed gross weight limit. The entire roof structure weighs less than a hundred pounds!
This one is heated by propane with a Scandia heater. The ample rocks make good löyly- in fact they were still warm when I went out tonight to check out the Moon chasing Jupiter and Venus through the sauna window.
Several years ago, feeling a need for a change, I sold my house (and sauna), but the new mortgage rules discourage banks from lending to self-employed folks like me and have kept me in a renters trap. I don’t mind the mobile existence for now, but I do miss my sauna. The trailer sauna is the perfect solution: no matter where I end up, I can take it with me! So, if you are a renter but dream of owning a sauna, there is a solution.
Looking back on recent sauna projects, I see a shifting trend in color choices made by my clients. From authentic dark brown Viking tar, to blue-grey, then, brighter reds and blues and greens, and now, this latest color feast. There is also a trend in design to use more bright colors such as on the running shoes I saw in the gym yesterday that were an eye-popping florescent orange. I have been following the designer Ingrid Fetell Lee who writes about creating joy with color in her book 
The one thing that always comes up when people ask me questions about building saunas is: how do you insulate it? Intuitively, one might think that the sauna, with it’s high temperatures, would need more insulation than a house and should be as tight as possible to conserve energy. In fact, I’ve had building inspectors give me a confused list of requirements using such logic. The reality is that a sauna is such a different beast than a living space that most of the calculations have to be thrown out the window. R-value, the number printed on most insulation products, is the resistance to heat flow of a given material for a given thickness for a given temperature difference (delta T) between the hot and cold side of the material. Typically, in our region, delta T is assumed to be 35° but, in a sauna, the delta T might be 165 degrees Fahrenheit! So, in terms of heat loss, we get some very different calculations! To really understand R-value, you need to think in terms of it’s inverse: the U value, or coefficient of heat transmission. U value is expressed in units of Btu/hr/sq. ft./°F, or, plainly, how much heat is lost per square foot for every 1° temperature difference. A typical sauna, with R-13 average insulation, might lose 4000 Btus per hour (or 1200 watts). But, A typical sauna stove generates 25-40,000 btus of heat per hour, so losing 4000 btu’s is not a big deal. (It is more important if you use an electric heater: an 8 kw unit, can only put off about 20,000 btus in an hour.) The other factor to consider is that, unlike a living space, you are not trying to hold the heat for very long. So, you don’t need to stack up piles of insulation in the walls and ceiling. In fact, many old saunas had no insulation at all.
Recently, I was called upon by a couple who had bought a property with an existing sauna that needed some professional help. The structure was a cordwood affair: a building method where timber framed walls are in-filled with short logs, stacked like firewood, with mortar between them. It looked like it came right out of the pages of Rob Roy’s classic how-to book: The Sauna. The exterior was fairly solid and quaint in a hobbit kind of way, but the interior, in terms of functionality, had some serious flaws. The timber frame and log and mortar walls looked pretty good, but it is obvious that the project was a classic DIY affair: a case of a homeowner taking on a project that looks easy, but with complex details that get skipped due to a lack of knowledge, funds or basic skill.
