Anybody built a wood fired sauna?

[Askel]

My bike workshop project seems to be coming along fine, so I'm on a bit of a roll.  Would love to have a simple wood fired sauna at home. As cheap as possible.

I've got lots of examples to work from in my neighborhood, as backyard saunas are kind of a thing around here.  However, much people build way bigger than I need. And second, I'm working with a self imposed limitation of using a stove I already own. 

I currently have a small snowtrekker stove I use in my tent for maybe a week or so every year: https://www.snowtrekkertents.com/portablewoodstoves.html

It can put out enough heat to get an 8x10 canvas tent above 60F in single digit temperatures, so I think I have a shot at making it work as a sauna stove.  Just throw a metal mesh basket of rocks on the top and away we go. 

Thinking of a 6x6 lean to style shed to start with.  Very short on one end, maybe only 5' or 5.5', to just over 6' at the back (enough clearance for me to sit upright comfortable on the upper bench).

This is the only thing I've seen that gets kind of close to what I'm envisioning:  http://www.instructables.com/id/Wood-Burning-Sauna-DIY/

Things I haven't figured out or decided on yet.

1. Insulation in the walls, roof, and under the floor? I kind of like the idea of a structure that can breath- especially one going through some pretty crazy heat/moisture cycles.

2. Vapor barriers? Probably necessary if I use some kind of insulation, but I'm not really sure it's necessary on an outdoor sauna. 

3. Flooring? I'm half tempted to just lay down some concrete pavers on the ground and build on top of that. Just let any water that falls to the floor drain naturally. 

[trammatic]

I like the idea of simpler.  I'd build the simple structure you're planning and then go from there.  Does it get hot enough?  If not, then start adding fancy insulation, etc.

[Syonyk]

Following.

I'm considering building a basalt sauna after I build a basalt root cellar... in, you know, a few decades.

[Askel]

Built out of rock would be interesting. At least you'd have no shortage of sauna rocks. :D

Researching this on the internet has been the absolute worse.  Everybody has an opinion, and anybody who disagrees with them is dead wrong.  The loudest culprits seem to be those who stand to make a buck or two on the most asinine things- like authentic Finnish sauna rocks. 

I'm now kind of looking forward to experimenting just to see what is bullshit and what isn't.  It's too easy to overthink this. All I need is a room that gets hot enough to raise my body temperature enough to do naked snow angels in my yard.

Stay tuned as I'm maimed from exploding sauna rocks, poisoned by out-gassing of formaldehyde from plywood used in construction and inflicted with killer allergies from mold by not using the appropriate sub species of cedar. 

[Cowardly Toaster]

Depending on where you live an your skill levels, a log sauna is an option. Heck, you might be able to even get a little load of cedar logs to do it. That would be the ideal.

[Syonyk]

My property can safely be described as a thin layer of dirt on a pile of basalt.

I have infinite supplies until proven otherwise.

[worms]

Once, when looking for a property to rent, I visited one where the current tenant was from Finland.  His back-yard sauna was a very simple home-made hut and a wood-fired oil-drum stove. I liked the sauna, but not the house, so never experienced the sauna’s practicality. 

My take-home message, though, was that a sauna can be really simple, so don’t overthink it!

[Fishindude]

Never built one, but used one at a remote bunting camp in AK.   It was a simple 8' x 8' structure made of all rough sawn wood (locally milled), wood floor, un-insulated.
It had a bench at normal floor level, then a bench behind it maybe 4' off floor where you could get more heat.   Heat source was a simple homemade, small steel wood stove sitting on concrete pavers.   They makes a "bag" of chicken wire filled with rocks and it draped over the stove.   There were also many rocks on top of the concrete pavers and surrounding the base and back side of stove, creating a sort of stacked hearth.   A gallon or so kettle sat on top of stove with a ladle in it and you would pour water over the stones to create the steam.   

This deal was very simple and worked great.   

[Chestnut]

Do it!  Finished our woodburning sauna a year ago and love it.  Saved a bunch of money by collecting materials like sauna doors from Craigslist.  Got an incredible deal on T & G cedar for the interior walls from buying a pallet of damaged shorts.  Used everything we cut out as firewood in the sauna : )

Highly highly recommend you go to this guys site and read all of his posts on building your own sauna:  http://www.saunatimes.com

I bought his ebook and it was definitely worth it, plus he offers to help answer questions along the way via email.  I would also be happy to answer any questions you have.  The 3 questions you have below are some key decisions you will have to make.

1 and 2: We used rock wool batt insulation in between studs, then layer over that w/ a reflective vapor barrier, then the cedar tongue and groove over that.  Got the idea from the blog mentioned above. It works great. 

3: I did exactly what you mention here and it has worked out great.  I took the time to build a proper 12' x 12' patio w/ 1' pavers.  Then we built the building on top of that.  Any water just drains into the sand between the pavers or evaporates.  We didn't want to use any pressure treated or glue seeing as though we do a lot of deep breathing in there.  This idea helped us avoid having to build a drain that would have made it more complicated.

The 12 by 12 footprint includes a 4x12 covered porch, 6x8 changing room and 6x8 sauna room that can fit 5 people very comfortably.  It's crucial that you don't build your ceilings too high. We built an outdoor cold shower to cool off between rounds.  I can also help you pick out a stove at a good price as I spent a lot of time looking.  I would recommend getting a proper sauna stove even though you can sometimes find normal wood stoves for cheap or free on craigslist.

All that said, it's a very difficult project to do well and "Cheap".  You can definitely save some serious cash on some aspects (2 $500 doors for fifty bucks on CL), but it's still going to be difficult not to spend a few thousand bucks doing it the way I describe depending on the size.



1. Insulation in the walls, roof, and under the floor? I kind of like the idea of a structure that can breath- especially one going through some pretty crazy heat/moisture cycles.

2. Vapor barriers? Probably necessary if I use some kind of insulation, but I'm not really sure it's necessary on an outdoor sauna. 

3. Flooring? I'm half tempted to just lay down some concrete pavers on the ground and build on top of that. Just let any water that falls to the floor drain naturally.
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[Mgmny]

I know this post is a few months old, but thinking of doing this as well. Seems like the "cheapest" wood fire stove I can get is a guy who sells barrel (old 55 gallon drums) stoves locally for $150. I haven't seen these in too many applications on the web as a sauna stove, but i think it should work?

Anyone have any better/other insights for saving on the stove portion of the sauna?

[Alternatepriorities]

I know this post is a few months old, but thinking of doing this as well. Seems like the "cheapest" wood fire stove I can get is a guy who sells barrel (old 55 gallon drums) stoves locally for $150. I haven't seen these in too many applications on the web as a sauna stove, but i think it should work?

Anyone have any better/other insights for saving on the stove portion of the sauna?

My father has heated his house with a self built "barrel stove" for at least 37 years. For reference he lives in interior Alaska and his house is probably around 2000 sq ft. He's been heating 100% of his hot water with it as well for the last 25 years or so. In that time I think he's gone through about 3 barrels. If they are well built they are great stoves and extremely mustachian. However, a 55 gallon barrel stove is complete overkill for a sauna.

My brother built a sauna about 20 years ago using salvaged cedar and other lumber from a job our dad was working on. I think it's about 10' x 6' with the stove and door at one end and a bench down either side. It looks a bit like the picture in the instructables link and will seat 4-6 comfortably. He didn't put in any kind of vapor barrier or insulation, but has plywood on the outside of the 2x4 frame and cedar on the inside so there is some insulating value for the air gap. He used a barrel stove lined with lava rock. I think it is a 30 gallon barrel and it can cook you out of the sauna down to about -40 if you are not careful. Our dad doesn't use it much, but my brother and I still use it whenever we visit and it's holding up well. Definitely get's us warm enough for snow angels. Sometimes we jump into a tank of 36 degree well water during the summer.

A couple of lessons:
Nails or screws in the benches get really hot. It'd be best not to have any exposed where you might touch them (countersinking the screws was not enough once the wood shrank).
Try to keep rain from coming down the stove pipe when it's not in use to make the stove last longer. Rain mixed with ash will rust out the barrel pretty quickly.
I have seen rocks explode when they get hot, but we've never had any problems with the free lava rock he gathered and broke up for it. Don't short yourself on the rock though, using lots of rock helps keep the temperature constant.

It's going to be a few weeks before I am back there again, but I will try to remember to take some photos of the design.

[Alternatepriorities]

Following.

I'm considering building a basalt sauna after I build a basalt root cellar... in, you know, a few decades.

I hope you get to this sooner than a few decades. It would be interesting to hear how it preforms and how it takes to get it hot inside.

[Syonyk]

I have many, many projects before that one. :)

[Alternatepriorities]

These might be too late to be helpful, but I made it up to my dad's house over the weekend and took some photos of the sauna my brother. We still use it about a five times a year and it's holding up pretty well for it's age. The wood inside and the front is cedar siding he salvaged from a local renovation out dad was working on. The stove is a small barrel converted to a stove with door and chimney collar kit. I don't know if they still sell those kits. We've been reusing the kit parts with new barrels my whole life. That barrel is starting to rust out after 20 years, but it still works and all we've had to replace so far is stove pipe. The temperature was around 0 this weekend and we had to leave the sauna several times to cool off.