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.
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!
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.
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.
