Sauna Builder’s Year in Review

Ice Lantern and Saunas at Rob Licht Custom Saunas
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 on display at Rob Licht's Shop in Lansing, NY
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.

Yoga and Sauna Retreat
Garage Retrofit for Hot Yoga and Sauna
Idyllic Creekside Sauna
Classic Creekside Sauna set 50 ft from swimming hole. Idyllic.
Basement Electric Sauna with multi-tiered bench design and view of the gardens.
Walkout Basement Electric Sauna Bliss
Urban Backyard Sauna with electric heater imitating the architectural detailing of the house.
Backyard Sauna Design, Urban Collaboration in Syracuse, NY
Rustic Elegant woodburning sauna surrounded by trees
Rustic elegant wood burning sauna
Cozy 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.

Scarlet by the Lake, ready for a cold plunge
Taking Sauna with Scarlet by the Lake, December 2021.

Follow the saunas on instagram @saunasbyrob

The Last Word on Foil.

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. 

NOT sauna foil.
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.

Proper sauna insulating with an air gap on backside of cedar.
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. 

Sauna thermodynamics by sauna builder Rob Licht Custom Saunas
The thermodynamic experiment begins.

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.

Team Effort

Sauna Design and Interior by Rob Licht Custom Saunas / Exterior by Deblois Renovate and Remodel of Fayetteville, NY

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.

Sauna Interior

Sauna Design and Interior by Rob Licht / Exterior by Deblois Renovate and Remodel of Fayetteville, NY