Introduction: Wood Burning Sauna DIY

Picture of Wood Burning Sauna DIY

This is my first Instructable but I have used so many for ideas and love the community input!

I live in downstate Michigan and went to college in the UP met a whole crew of Finlanders and was introduced to the Sauna! and its pronounced SOuna not SAWNA but i still slip from time to time if you arnt a yooper it takes time.

I graduated and moved back downstate for work but my life was lacking because i no longer had access to the "poor mans medicine box" so naturally i want to fill that gap. Research began to see my options for having my own sauna. Student Loan debt is a mother sucker and takes up a large portion of my income so $$ was tight so building looked better than buying and of course is much more rewarding.

I searched the web and found a few things but nothing really helpful for building a finish style  wood burning sauna. I am getting into woodworking its becoming  my after work hobby and this was the largest project i have done and still have a few things ill get to at some point. So I winged it at times but at the end of the day the sucker works as intended.

Step 1: Fall 2013 Update

Picture of Fall 2013 Update

The Sauna has been up and running for over a year now and been used about ~70 times. It has grayed from original yellow looking pine on the exterior and the cedar interior is still aromatic but less intense after time has gone on. The window that cracked has been replaced by an vinyl window picked up from Habitat for Humanity for $20 and a woodbox/bench has been built. Over the summer it didn't get used weekly but now that fall is here it is Sauna season!! I also improved the rock to stove pipe ratio by taking a section of steel wire rack and bending it to create a cylinder. The heat has been able to be held for a much longer time with these additions and looks pretty good with the flowers in bloom.

Step 2: The Stove

Picture of The Stove

I wanted to do this DIY and on the cheap and after seeing a few stoves made from propane tanks I checked the garage and we had a 20lb tank collecting dust. The tank had been used but was empty so I Took off the fitting with a little elbow grease and let it air out for an hour. I then filled it up with water and let it sit for 20 min. Then it got tossed in the fire pit and burned for an hour to remove any traces of propane and the nasty additive that I believe is poisonous. 

I wanted to keep the building small and fit 3-5 people so to save space I made the choice/mistake to have the tank sit upward. I went to the hardware store and purchased 8ft of 6" single wall stove pipe. Which i cut a hole  smaller than the pipe in the tank using an angle grinder. Lots of sparks and loud but pretty fast work. 

I made a door in the front and used steel banding and sheet metal screws to attach the strapping and door hinges. Because the tank was vertical not horizontal i had to create a baffle to keep the fire in the fire box and not in the stove pipe!  So i used a piece of plate steel and some bolts so i could adjust the air gap to the optimize draw but still keep the fire in the box.

Note: in the picture u will  see a piece of air duct on the tank this is galvanized and a big NO NO for a chimney end up with zinc poisoning but it is 6" and worked for a demo fit. I made a cage for the rocks using steel shelving.

I put on a section or 2 i believe of stove pipe and balanced it while i tested the baffle until i was happy. I was getting results i wanted and was ready to start building the frame for my sauna shed.

Step 3: The Game Plan

Picture of The Game Plan

Step 1 was complete I had a fire box that seemed to be working pretty good and i was able to do it weld free. I knew the project was going to cost a few hundred bucks but was going to be frugal and resourceful as I could without sacrificing to much time to save a buck. So I looked at what floor plans i could find on the web and for dimensional lumber reason I decided on 4'x8' and settled on a shed roof that would be 7ft on the high end and 6ft 4 on the short end.

I really wanted to have this be a legit sauna and cedar was the wood of choice. But no way jose would I be buying that much cedar at a big box store thats the opposite of a frugal build! 

So i searched hi and low to find cedar. We have several Amish saw mills around here but no cedar mostly hardwood that fuels the pallet industry but very cheap rough cut wood if you live in the country and you have access to a planner good way to go.

But I found a place with a resaw bandsaw that had 5x5x8ft western red cedar blocks that ran $18 per and could get them re sawn to any thickness

I also found a local guy with a tractor powered sawmill who had white pine for cheep.

So the plan was formed. I would build a frame using dimensional lumber and line it with ~3/8' cedar boards and then the exterior would be .75-1.25"  white pine. I could insulate and install a vapor barrier with 2 layers of wood sounded doable and heat worthy

To save $ I cut 2x4's in half and the frame was built one wall at a time. The pine boards were 9-15" wide and 8-11 ft long and varied from .75-1.25 thick. I ripped each board in half and was left a variety from 4.5 to 7.5" wide.

I used a ship lap of about 1/2 inch on each board to create a more air tight seal because the boards are gonna move around with the moisture and the changing of temps. I didnt use any pressure treated wood in this project for health concerns so it may only last 5-10 years but by then ill be ready to build another one! The wood will age and enhance the rustic look.....

I had the four walls mostly built but was ready to see the space i had created so using the tractor and a trailer moved the walls into place and got some screws in and i was happy to see the 4 walls were square enough and standing strong.

Step 4: Button It Up

Picture of Button It Up

I continued to nail up pine boards until the exterior was up to the roof level, which is at an angle so the boards near the top had to be cut at an angle to follow the roof pitch. My dad gave me a hand and we framed out the roof and purchased some steel roofing in a lovely forest green. 

The door was made from left over pine boards that already had the ship lap cut in them and a ~100 year old window I found in the attic that imagine was from when my parents house was built. I wanted to do a curve door but should of just stayed square would of been easier...

I attached a spring to the door and wall to keep it closed and that heat in!

The window was made from a plate of glass that I had laying around. 

I had a whole mess of plastic sheeting from past projects and using a stapler I created a vapor/wind barrier on the inside of the frame. I came across 3 sheets of polystyrene foam insulation board and cut it to fit between the studs on all the walls and the roof expect in the area where the stove pipe will be.

I then had my cedar hookup cut me up enough boards to line the inside with the western red cedar. Each board was 5.25 inches wide and had to to be touched up with the table to be square enough for my liking.  I chose not to ship lap these boards and just lay them on top of each other and use an air nailer to make this step a little faster.

I did a wall at a time and it did go quick. I then was ready to cut a hole in the roof for my stove pipe. I measure to where the pipe would need to be and then using a jig saw and a fresh blade i cut the opening and put some pipe in and set the stove in place.

Its not a perfect fit and when it rains water drips through but its minimal. 

I had some cement board around and used that as a barrier from the wood stove and the walls its not the prettiest but so far has done its job.

I wanted two rows of seating at different levels so I ended up going with a bleacher style set up and used  left over cedar and oak for that it fits 4 people full house and very comfy with 2.  Not the best pics on the inside the lighting makes it hard to show.

Under the bench is open and i currently store fire wood and the water bucket there but i may add some boards to close it in.

Step 5: Stove Redo

Picture of Stove Redo

Well it was looking like a sauna and technically did work but It would take 2-3 hours to reach temps of 150 degrees. And never really was hot enough for my liking. The stove had great draft but i think a large portion of heat was lost out of the top of the stove pipe based on the vertical design. So I searched craigslist and found a larger 30lb tank for $10.

This time i wasn't messing around I wanted to keep more heat in the building and opted for the horizontal design which appears more commonly done with the propane tank wood stoves. It was a good move, and basically repeated the same process and built some legs and  a larger door than before and cut up the old stove to use as a baffle for the new one. which fit like a glove because it follows the curve of the tank.

I also used a section of the old tank where the door was cut and turned that into my rock holding tray. Which my brother grabbed a load of rocks from a quarry and so far non have exploded...

Now the sauna heats up rather quickly in about 45-1hr its ready to use.

Step 6: 4 Months In...

Picture of 4 Months In...

Sauna has been up and running for 4 months now and gets used about twice a week. It burns about half a wheelbarrow of wood each fire so that has been my biggest challenge is finding dry fire wood. Having the right wood is key so much easier to get the hot box up to temp if you have a dry supply.  This summer I will stock pile up but so far burning pallets and scraps from the sawmill. I avoid burning plywood or pressure treated but oak pallets burn hot.

The wind also plays a big role in the draft and a slight breeze seems to be best for the quickest hottest fires. I had a whole bunch of  oak and pine strips and on a 18 degree day had the sauna at 201 degrees which is as hot as i go, usually 175 is my zone.

We got some wet snow and eventually rain but u can see the snow difference on the roof from before and after a fire.

I use a kitchen thermometer to gauge temp and that hangs 6" off the ceiling on the high side of the sauna hit 175 today.


Step 7: Review

Picture of Review

If you live in the country and dont have major zoning/building code issues to overcome this is a totally doable project. It is a little messy and ash tends to get on the floor. 

Stove design is key and the next sauna i build i may just find a used woodstove and save the headache. 

Cedar is nice but i might just go all white pine it smells so good and is cheep and really haven't had issues with sap.

The window was kinda of bust it basically is a huge heat loss and didnt last long the plate glass cracked and for now is covered up with plywood, ill be keeping my eyes open for a small window.

I used alot of scraps from other projects to build this and spent about $325 in supplies. U might be able to spend less but not with out sacrificing time time time. 

Feel free to leave your comment and ask questions. I am the type of person who learns best from doing things on my own, They may need to be improved but thats learning. My dad is a mechanic and my brother is an engineer so I am constantly told how i could of done things differently, yah well i didn't so to bad!

Thanks Enjoy!!!!!


EddieK16 (author)2017-03-02

Ok Finn's other experienced people, do you need the vapour barrier? i was planning lumber of some sort outside, cedar or pine inside? seems to me the sauna will be steamy, but for couple hours after the sauna is done it'll still be hot, also would the vapour barrier not actually hinder a drying out process? Lastly if not using vapour barrier is rock wool sufficient insulation, or something else?? thanks m

millere65 (author)2015-04-03

Looks good! A suggestion for you for a cheap but heat proof window. An old oven door window can be picked up for next to nothing and should be a lot more stable for you. You'll of course need to frame it yourself but that's half the fun.

EddieK16 (author)millere652017-03-02

nice I dea, like it!

PemaC1 (author)2016-08-15

Does anyone know of a carbon monoxide monitor that is suitable for a sauna? Most of them can't be used in a heated or humid environment. I can't find anything online and wondered what others have used?

smitdawg40us (author)PemaC12016-10-23

No, but if you nee a CO detector, then your Sauna isn't safe to begin with ... with your concerns, I would opt for the infrared (electric) heated unit.

TobiasB38 (author)smitdawg40us2016-12-28

This comment is smug and unhelpful. Instead of telling everyone how sauna smart and experienced you are, why not just explain why you feel a carbon monoxide monitor is unnecessary for a sauna. It is a rational concern: small rooms with wood stoves can be dangerous (we've all experienced down drafts filling houses and cabins with smoke)

canuckfinn (author)TobiasB382017-02-07

Speaking as someone of finnish descent and who grew up using a sauna almost daily, a properly built sauna will have the feed for the stove on the exterior of the sauna, which means a CO detector shouldn't be necessary. I would never recommend going in a sauna which feeds the stove inside the sauna room.

EddieK16 (author)canuckfinn2017-03-02

I've used wood saunas in Finland where they were internal. never heard of a problem. I suppose as Finns use them like crazy as a nation there must be some level of annual incidents ?

EddieK16 (author)TobiasB382017-03-02

What he is saying is if you have doubts about CO you would not use such a sauna. you wouldn't take the risk, hence never having a CO monitor. All the Finnish saunas I have been in, are very well ventilated, and the process of dousing the first Loyll of water (excuse spelling) eliminates any remaining embers.

TaylorK1 (author)PemaC12016-10-19

hi Pema I'm looking around for the same thing. Let me know if you find anything. I was planning to use a household CO monitor and seeing what happens. I'm almost done with my sauna and have fired up my stove once. I used a multirae gas meter from work and the highest the CO got with stove doors closed was around 8 ppm which I hear is not so good to be sitting in for a prolonged period. Thanks

TheUglyBarbarian (author)2016-08-07

very inspiring. I am retiring soon, I hope to build a sauna next to my cabin (after I build the cabin, lol). You (and your commenters) have brought up several good points to consider for the project.

Thank you.

juels98 made it! (author)2016-05-10

Thanks for the inspiration. After wanting to build a sauna for many years and scanning through many build sites like yours, I finally decided to try my luck and built a 12'x14' sauna consisting of a 6'x12' hot room and an 8'x12' changing/party room. I tried to document as detailed as possible each step of the build hoping it helps someone like us that tries this DIY project. My writeup and photos can be found here:

Thanks again!

Gr8Horned (author)2016-05-03

Awesome Project!

Can I ask where you sourced your Cedar from? I live in NW Ohio and I may be able to use same source.

Thanks, Dustin

Invention1 (author)2015-01-01

RE: Exploding rocks. This is a big risk but a little basic geology knowledge will help you out. We have built a lot of native-American style sweatlodges using hot rocks for heating, just like a sauna except made out of tarps and blankets. Chert, which is commonly found associated with limestone, will explode when heated. Shoots hot splinters all over the place, one time right through one of my tents. Many other kinds of rocks will not, (this is based on experience) including granite (might be common in Michigan?) limestone without chert nodules, sandstone. Most igneous rock (basalt, granite, etc) should be OK. I'd probably stay away from Shale, Coal (this could burn!), and anything crumbly (might hold water which could explode).

Keep this in mind: Some rocks are Gneiss-er than others, but you can take it for Granite that these should be fine. Your sauna will be hot, not Coal, if you follow these instructions. If you can't keep this list straight, put it into a checklist on a clipboard and keep it as a Chert on the wall. Never Basalt your food before tasting it. Now the judge has finally banged the Gravel.

MichaelJ159 (author)Invention12016-04-26

Should I use a clipboard or a SLATE chalkboard? Lol

BrennanC3 (author)Invention12016-03-15

Be careful with the sandstone. I had a piece of flagstone explode violently and crack a cast iron wood stove. The stone was sitting on top for about an hour before exploding. We were lucky no one was hurt. The stone hit the fence behind us with some serious force and had all the dogs in the neighborhood barking.

Yakaboochi (author)2016-02-19

Thats excellent! My wife and i plan to build one just like yours in the near future! I will be using a small woodstove in ours. Nothing like a good sweat on a cold winters day!

PetervdPol (author)2016-01-18

YEAH!!!!! I want this. And a cold shower.

Jedi_zombie85 (author)2016-01-18

Very nice

CraftAndu (author)2016-01-17

Aww yeah! SAUNA. Are these things really so rare. We do this every weekend! ( in Estonia)

3366carlos (author)2016-01-16

good project, I don't know much about SOUnas but seems to me like having a carbon monoxide sensor would be a good idea. Congrats on your project.

JyriV (author)3366carlos2016-01-17

it would just go nuts because of the heat and steam (you do know the rocks are there for throwing water at them, right? hot rock+water=steam, which is good for your health), so no point there. there's really not that much of a risk of carbon monoxide if there's enough draft to keep the smoke going out of the chimney.

lokahi07 (author)2015-12-24

Hey have you ever heard of making a sauna out of cement cinder blocks? I have a bunch of them sitting around and wanted to know if you think they would work...

JyriV (author)lokahi072016-01-17

that would not be a sauna, that's a bunker. trust me, i'm finnish and i have built a few saunas before.

TylerB14 (author)2015-05-25

enjoyed your diy so much it inspired me to have a group of my building trades students make a similar sauna. They had to research first and found they used slat floors, poplar benches (don't hold heat). They made it so it was a true 4 x 8' on the inside. Thanks for the inspiration!

jrytlews (author)TylerB142015-05-25

Wow! Thats beautiful! Your students did a great job. I live in Florida now so when I want to take a sauna I just sit in the car with the windows up...

Does someone get to take it home?

TylerB14 (author)jrytlews2015-12-10

We sold it for 3200... Ul approved stove and chimney. Cedar tongue and groove on the inside. We are located just outside of duluth.

TylerB14 (author)jrytlews2015-05-25

I opened it up for students to buy it first, not much interest so I am hoping to sell it and make a little for the program.

ScottS123 (author)TylerB142015-12-09


I realize I may be way late on the take here, but did you ever sell the sauna your students built?? Do you still have it? I am in southern Michigan and have been looking for used ones on the cheap. I looked into the barrel kits, but they are quite pricey. I may have to try a DIY:)

TylerB14 (author)ScottS1232015-12-10

yes we sold it. We are thinking of putting together another one. The 4x8 was a bit tight quarters so we may open this one up a bit larger. Let me know if your interested. It would be done mid may.

ScottS123 (author)TylerB142015-12-10

I would be interested if the price was right:) If you don't mind me asking, how much did you sell the sauna for? Where are you located? I am also a teacher....6th grade at Mattawan Middle School.

ScottS123 (author)2015-12-10


If you don't mind me asking, how much did the other one go for? My budget would probably be $1500 or less. I would be interested if the price was right? I am a teacher myself:) Where are you located?


Two Paddles Design (author)2015-11-21

We are exploring DIY Sauna's right now, thanks for the inspiration!

JoshuaC20 (author)2015-07-05

This is absolutely awesome! I have been thinking about building a sauna for a long time, but I'm waiting until I choose which one to build. I have found on the internet three different types. Traditional saunas, infrared saunas, and portable saunas.

So far infrared saunas have seemed to be the most simple/efficient to buy and build. There are many kits out there that are relatively cheap for the value that they provide. Has anyone tried infrared saunas before? The best information I have found about them so far has been from this page

If anyone has experience please reply back as I'm leaning towards this type of sauna.

deluges (author)2015-06-23

Thanks for this instructable, the instructions are much appreciated and I'm looking forward to try and make my own

SKall (author)2015-01-01

Nice project! A few years back I (well, mostly my dad) we did a backyard restoration; refinished the pool, built a deck + a woodburning sauna. Unlike yours mine was done with bought material including the kiuas (stove).

Pictures of the whole project:

1) Insulating the walls would help greatly since the wood used is quite thin:

2) Adding a brick firewall around the stove would be a good security feature:

3) Fire-proofing the pipe exit hole should be done with extra care:

Enjoying the fin(n)ished product in Texas winter:

I have since moved to Florida and in the next few months I will start building an electric sauna inside the house.

deluges (author)SKall2015-06-23

Thanks for potting those pictures and great work! I plan on building one on a budget for my parents this summer and your pictures are good inspirational material

kelms1 (author)2015-05-18

Great indestructible I also just saw somewhere a article about the major health benefits for a man's heart using one of these !

GrizzlyT (author)2015-04-24

looks like it could be a nice smoke house too with some small changes...

Philipd1 (author)2015-01-06

Well done... a project I have always wanted to take on but local zoning has made it questionable. I like your resourcefulness in building, planning and cost control. For the next sauna many big city municipalities are banning wood stoves in certain provinces like Quebec thus giving an opportunity to pick up a wood stove for scrap metal cost. See a dealer and put in a request now and store the stove for future use thus giving time to pick and choose. They store easily outside covered. They will likely give you the address with the clients permission and you can pick up a wood stove for the $100 or less. It is picking it up. Check online to see which municipalities are banning. Nice project.

Mugsy Knuckles (author)2015-01-04

Just putting this out there, but wood dries really fast in a 150 degree sauna. Just sayin'.

kmarie22 (author)2015-01-02

I love this idea of a back yard sauna. Thank you for posting your project. It is years away for me but I like knowing that the plans are out there.

StevenSlaughter (author)2015-01-01

Nice job! I really miss our sauna. We moved from Chicago to Nairobi, Kenya. Though the evenings can get chilly here, it wouldn't be quite as satisfying to build a sauna -- at least not compared to the crazy cold and snow of the Midwest. After seeing the kit prices, I built mine from scratch in my house's old root cellar. Excellent location if any of you have one and aren't really using it. The thick cement walls and partially underground location is ideal for insulation. Being inside without access to a flue, I bought a new electric sauna stove. Not as nice as a wood burner, for sure, but necessary. Also worked with a great lumber mill (in N Michigan) for cedar. They were great. While not a kit, they did use my drawings to cut sizes to just over my dimensions, making for very little waste.

One thought on anyone wanting to build one... you might want to invest in foil-faced insulation. In addition to a vapor barrier, I covered all of the framing with this, sealing it with foil tape, and it not only insulates but bounces back the heat into the room.

Though I'll never complain about the temperate climate here, I would love to teleport back for a weekly sauna during a Chicago winter, complete with some cycles of jumping in the snow and dumping buckets of water over our heads out in the backyard. Good times.

superlite (author)2015-01-01

I have built a number of sauna/ Bania stoves and buildings, the first thing to remember as a previous contributor mentioned the stove is best when fed from the outside with the chimney running horizontal going out above the stove. The stoves i have built have been made from steel pilling cut offs with a bock and a door welded on along with the chimney adapter welded on the top. My home sauna is built from logs with one large double glazed window the room is 10' by 12' and heats up to 180+ if anybody would like pictures I would gladly provide such.

As far as the mention of the temperature measurement system is concerned......deg Fahrenheit are quite simple and it does not take much imagination or intelligence to deduce the nature of the scale being used. The arbitrary use of the boiling point and freezing point of water as the basis of the system of measure has a few problems related in it's own right, along with the arbitrary use of inconsistent standards for measure that are employed in the same system.

crispernakisan (author)2015-01-01

Yeah, you'betcha, dis' here is a nice instructable. Holy wah!

mnealgibby (author)2015-01-01

I failed to mention in my previous comment that lining the propane tank with fire brick will increase the thermal mass of the stove and help it stay hot longer.

mnealgibby (author)2015-01-01

Nicely done!

The propane tank stove and black stove pipe definitely don't meet clearance to combustibles, but being a shed out back, who cares really. You could get 4" inner, 6" outer double wall flue pipe to decrease the necessary clearance around that flue. That would also lessen the chance of someone being burned. Another added benefit of the smaller inner flue pipe is a bit slower burn time. Adding another offset may also increase your burn time. I'm sure you already know, but choking down the air intake or closing up the baffle will slow the burn.

For the leak take a 2" piece of thin sheet metal wrap it around the flue and attach it to the roof with screws or rivets so you have a 2" vertical wall that mimics the flue, but a bit wider than the flue pipe. That is called a spin collar. Seal that piece to the roof with NP-1 and then take another piece of sheet metal and wrap it around the flue above the spin collar. It will make a skirt over the spin collar, called a storm collar. The storm collar can be screwed to itself. Seal that piece to the flue with high temp silicone and you will no longer have leaks. This apparently is a bit difficult to explain, but I can send you pictures to illustrate if you would like. Depending on your Google-Fu, you may be able to search out an illustration.

1/2" or thicker acrylic could be used for your window to mitigate heat loss.

Source: I am a home builder and certified chimney sweep.

hemi1234 (author)2015-01-01

I used an old stove and moved the pipe from back to front, then put a baffle inside. Essentially, the door and pipe are outside the sauna, the only thing in the sauna is about 2 feet of stove(the rear). It heats to over 170 degrees in an hour and sits 6-8 people.

paolobertoncin (author)2015-01-01

Great job ! How I like it!!!

Rapturee (author)2015-01-01

Great Job! :{)

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