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 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!
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.
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
