A mobile sauna build project that the most amateur builder can Finnish on their own

I picked up my $9,300 mobile sauna shell from Eric, Voyageur Custom Saunas. What a great time to bare down and build an awesome mobile sauna. The garage is a perfect work station. We can apply a few hours each day to advancing the Finnish product, our own health and wellness mobile retreat.

Please welcome to the video chronology of turning this mobile trailer shell into a really awesome mobile sauna!

Building a mobile sauna – sauna benches in action
Day 1: bringing the 7’x12′ mobile sauna shell to my driveway

Day 1A: foil wrap. Creating a sputnik foil insulated thermo heat insulator thermolator

foil wrapping the mobile sauna

Day 2, tongue and groove

tongue and groove cedar day 2,

Day 3 is more of that.

Day 4 – 10 deep Wim Hof breaths and procuring stove pipe material from the big box outlet. For many this is the least favorite part of building a sauna, including me. But we need to purchase the stove and chimney pipes and components for our wood fired sauna stove. In addition to information in my ebook, you can click here for a detailed list of what you need.

Day 5: pivoting away from building common wall to building sauna benches.

Day 7: The Common Wall. I elected to go with 2×2’s instead of 2×4’s for two reasons: weight and space. We gain 2″ by using 2×2’s in stead of 2×4’s which is something more than nothing, and every inch counts when we are designing a sauna within a 7’x12′ ice fish house chassis. And same goes for weight. Sure we’re going to put in a 450 lb. stove, but this is our choice of no compromise. Anyhow, here’s the common wall going up:

Day 7: Mobile sauna build

Day 8:

Day 9: Having lunch with Plumb Bob, a critical partner in crime who allows us to define exactly where our stove is going to go, and by extension from that, exactly where our chimney stack is going to go. This is a stage where, unless we get Plumb Bob in the mix, we may be more apt to really screw things up, painting ourselves in a corner by having to cut a rafter to fit in the chimney or forgetting about heat shields or air gaps, so that we have to rip things apart to fit, or sell out and have to purchase expensive elbows to fit our stove into a space that we didn’t initially intend.

Welcome Plumb Bob:

a lame day as I was tired

Day 11, working through a little lull in the action and a bit of shortness of energy. We are able to show you how stove surround is very important. We like a double course of durarock, with 1″ or 1 1/2″ air gap. This air gap works exceptionally well as we are able to encourage cooler air from below to circulate up through the chamber, keeping our wall cool. Further, the inside layer of durarock doubles as a thermal mass actuator, a fancy word for providing heat mass for our hot room.

Day 14: Hair is getting unruly, but we have turned a major corner, and you’ll get a good assessment of the end zone. A messy day of hot room door building and side bench building, where after dealing with this the taste of a nICE cold beer is sure welcome.

Day 14, mobile sauna build

Day 17, stove is in and crackling away!

Day 17, mobile sauna build

The final day! 60 labor hours and 17 days. I was able to take the first sauna in this new mobile sauna after completing all the Finnishing touches. There are a couple things not shown, like putting in a floor drain, but ultimately this is the best I can offer in terms of helping you with your mobile sauna build project. Hope this inspires and thanks for watching!

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17 thoughts on “A mobile sauna build project that the most amateur builder can Finnish on their own”

  1. Sam:

    Love the question. We wrestled this one to the ground. We even brought in the spray foam supplier and reviewed all the specs on the product. They say that off gassing occurs only during the set up phase of the material. Once solid and sealed: no off-gassing, even at temps North of 180-200f (which doesn’t get that hot in the wall cavity, anyway).

    But this may be like taking lung cancer advice from the Marlboro cigarette salesman, so I am able to sleep well at night with a spray foamed my hot room AND a hermetically sealed foil bubble wrap vapor barrier. The key is the foil tape and doing the “A” job with it.


    I seal the shit out of every seam, and end. The tape is awesome. If any air or gas can get through this membrane when i’m done with this phase, well, i’d be nothing less than completely astonished.

    I welcome more chatter on this matter as thinking about auffgussing is a lot better than thinking about off gassing, but as a sauna builder who appreciates taking things to an 11, I appreciate your question and hope experts in the field may chime in.

    Also, regarding fire, the key is how we box around our chimney as it goes through the ceiling as well as proper heat shields and distance to non-combustibles (solution: durarock air gap on wall surrounding stove).

  2. Just found your site and podcast. Looking forward to diving in. I live in military housing on a USAF state-side installation. I’m looking for a sauna that is also non-permanent, because I can’t alter the house I live in, and because we might move a few times. My wife and I disagree on heat source, but I’m curious if there’s a stove based (wood or electric) that is movable, or infrared if I must. Notice I didn’t say mobile: I’m not allowed to keep trailers in my driveway either!

    Thanks for the information!

  3. Brent, if it’s legal to build a shed in your backyard, i’d do that, and then what you do in that shed may not need a Govt. authorization form. Then when you move, you can move your “shed.”

  4. Hi Glenn:

    We talked a few months ago. Let me first thank you for all of the amazing information contained on your site. You’ve put together a gold mine of information and here which folks like me greatly appreciate!

    We are getting a plan together for a Sauna build at our off grid cottage on a lake in north of Georgian Bay in Ontario. Having spent a lifetime in a sauna that’s part of our larger family’s cottage on the same lake, we are looking at a sauna that will be approx 9 x 12 with 7 foot ceilings. With this we have a few Qs:

    1. Given our research and your earlier recommendations we are sold on Kuuma. We assume that for this sauna size we should get the Large Kuuma Stove?

    2. If we were to order a stove in coming weeks, what kind of time are we looking at given this strange new era that we are in?

    3. You earlier counselled on stove inside the sauna rather than installing it and feeding it through throat extension from change room. We are all for this, for reasons of efficiency, construction cost, and ambiance, but one question that has come up is whether, mid-sauna, if you are to feed the stove, how much particulate escapes into sauna room? We anticipate the new stove will be far more efficient than the 25 yr old model we have in the other sauna, and will require less feeding, but what are your thoughts on what happens when you do need to feed it mid sauna?

    4. We do not have a shower in our cottage and would like to make use of a space in sauna for showering with a simple shower system. We could do this with a combo of cold water mixed with hot from a side tank but could the hot water coil one sees on the Kuuma website be used for this purpose? What is the purpose of the coil?

    5. Once we have our design I would love to be able to show it to you to ensure we have ample room for the stove in the sauna chamber.

    Again thanks so much for furnishing all the info that you do!


  5. Hi Scott:

    Glad you found sauntimes and that you are benefitting from the material.

    1. Large Kuuma for sure is what you want for a 9×12 hot room. But do you really need this large of a hot room? I’ve backed dozens away from too large of a hot room and every single person has thanked me for the thinking. As you know, we sit on the bench for 10-15 mins. then at least that long outside in Nature or in cool down room, so as a rule of thumb, if building a sauna for 10 people to sauna at one session, think about a hot room to handle 5 or 6 people at one time. This allows you to create really kick as heat, and ample space to cool down, and thus really good flow. Under the same scenario, a hot room built for 10 people will probably never have all 10 in the hot room at one time (different cycle times). So, what you have is a big hot room, taking a long time to heat, with too much space not being used.

    2. Timing: The plant is still closed, so I don’t have an exact time. I’ll handle this question with you via email.

    3. Inside feed, particulates. I own two saunas each with small Kuumas. Built in 1996 and 2003. Thousands of saunas in each. I have had zero issues with opening the fire box and tossing in a log vis a vis smoke and particulates.

    4. The coil for the side of the Kuuma is available and it is a special add on that we don’t sell much of. It is to hook up to a Grunfoss pump and to create hot water. The conditions for this use is such that the sauna must be built in a place that won’t freeze, or the piping system must be blown out to avoid freeze. As far as shower goes, i’m not at all a proponent of shower in the hot room. It reduces the life of a stove. The humidity and splashing degrades the hot room and stove. Further, it is so much more satisfying to shower as part of the cool down. That said, for generations, the hot room has been a place for bathing. And for generations this has been done with a wash pan. And the hot room “recovers” after bathing, where the stove draws in fresh dry air and bakes out the hot room, which is hard to achieve with a plumbed in shower. Anyhow, i’m rambling. Both my saunas have an external side water tank and we absolutely love the warm water this tank produces, for löly water and for blending to make temperate water for shower action in winter.

    5. Yes, you can email me your design and we talk more.

  6. Hi Glenn!

    I’ve covered nearly all of your content at Saunatimes and all episodes of Sauna Talk. Thank you for all of your information contributions and sauna community building. With that said, I am ready to begin building my backyard sauna oasis here in Bloomington, MN. I’ve selected my site and am ready to break ground but first I am wondering if you can provide some feedback or suggestion as to the foundation for my sauna. Do you think it needs to be anchored to piers poured below the frost line, or would it be sufficiently stable set upon class 5 gravel and several prefabricated concrete footings that have the inlays for 2x framing materials. I’m not so concerned about wind moving it, as it is well protected. My concerns are more with shifting/settling from freeze/thaw. Thanks for your time, Glenn! -Dan

  7. Hi Glenn,

    I’m planning to follow your ebook to construct an 8’x12′ backyard sauna in Montana. Would the small Kuuma wood stove be adequate to heat the 6’x8′ hot room assuming a similar climate to Minneapolis?


  8. Hi Glenn – I too love sauans and am as american as pie as you ‘ve stated. I keep going around around on Cedar for other softwood though. I have gotten tripped up on the respiratory reactions cedar “may” place on people. Whats your take on the safety/toxicity of kiln dried western red cedar? I love cedar but im started getting worried about the effects of breathing the cederine/aromatics that are so potent (essentially an insecticide) on a daily basis in a heated environment. Heartwood spruce or hemlock would be my alternatives but im really hoping you can just talk me back into cedar =). Great blog (the question about the toxicity of foam made me think to ask this here). Is this something that has ever crossed your mind?

  9. Justin.

    I happen to love the smell of cedar in the morning. To me, it smells like victory. I have heard of those allergic to cedar, and for me, i just don’t buy any of the concept that cedar is an insecticide. Now, if i’m wrong here, and if I die an early death because of it, well, so be it. I guess Nature produces toxic stuff, like snake venom, but after a few sauna sessions, the smell of cedar dissipates, which is something, and to me very different than when the Chem-Lawn guy in his knee high boots tells the homeowner that the smell of their lawn spray dissipates because cedar is as natural as it comes. Just my non clinically proven logic and welcome links and studies on this matter.

  10. Good morning my name is Craig. I love what you are doing here. I will buy the 20.00 DIY if I can have 10 minutes of your time. 701-xxx-xxxx We live on Lake Mille Lacs I’m the guy whose insurance agent is struggling with. My Dad built us a Sauna in Rolla North Dakota 50 years ago. I have been a Sauna guy my whole life but have not had my own since 1976. Sure hope you will give me a call. Thanks for your time.

  11. Hi Dan:

    It’s perfectly reasonable to build your sauna on grade, resting on class 5. No footings, no pillars, etc. Having this structure rest on grade will allow you to level it if/as needed. I happen to like generous overhangs, 1.5 or 2″ and this helps shed water away from the perimeter, and it also protects the outside of your sauna building.

    Dan, hoping you invest the $20 for Sauna Build Start to Finnish. It has helped a lot of people with their DIY sauna build project, and I’m confident it will help you, too.

  12. Hi Glenn, Just purchased your E-book. (Order #31736) I ordered a pre-built shed 12×18 with 7 foot walls. I want to have either an 8×6 or 8×8 hot room, a shower/changing room, and a cool of room roughtly 12*10 (with a table, a couch and small kitchenette) . I want this to have a tiny cabin feel. Plan to host to my friends and family.

    So a few questions I can’t seem to find answers to:

    1. Would you recommend a 8×6 or 8×8 sauna for 6 people ?

    2. How do I go about insulating the floor especially in my cool off room and shower room? (I live in Pennsylvania where it gets pretty cold) .The shed will have 1″ pine floor boards as apposed to plywood. And the builders are installing a vapor barrier between the floor and the skid.

    3. Is it okay to place the stove on an interior wall? or is better to have the stove next to an exterior wall?
    Do you recommend the exhaust to go through the wall or ceiling?

    4. Looking at Kuuma wood heaters, they seem pretty awesome, I am curious why they sell the ash pan separately? Is it needed? How would you operate the heater without the ash pan?

    5. Is it possible to heat the rest of the shed utilizing the heat from Kumma heater? or should i just use an electric space heater?

    6. Where can i purchase a window for the hot room? I called local window guy, lowes, and home depot. they don’t seem to know what im talking about. Does the glass need to be special? From what ive heard it can’t have a vinyl frame.

    Thank you for your book and your resourceful website!

    Alex O.

  13. Hi Alex:

    1. 8×6.

    2. Many don’t bother insulating the floor. If you want to, i’d use rigid, 2″ pink stuff. You can run it through your table saw and lay in some sleepers 2″ below your sub floor inside each rafter and just rest them in there. Flush up. Critter proof. Great way to go.

    3. You can position your stove to an interior wall, and you’ll most likely have it in the corner with one exterior wall. Exhaust through the ceiling.

    4. Kuuma is the bomb. 90% purchase it with the ash pan as we pay for this once and benefit forever. You can order the stove through me, as I’ve become a distributor for the stoves, happily supporting and officially (now) promoting the family run company.

    5. You can heat a football stadium with that stove (almost) but having an electric space heater may be a good idea to keep your extra space temperate for between your sauna sessions.

    6. Window for hot room:

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