Introduction: Wood Fired Sauna
Inspiration:
I have been thinking about building a sauna for a few years simply because I love spending time in a sauna and I was looking for a fun project. The sauna was constructed behind my house in Denver, but it will be transported up to the mountains if I can figure out a way to get it on a trailer.
Concept:
Build a sauna that could comfortably seat four people and last for a long time.
Step 1: Flooring Joists and Decking
To build the floor I used 2x6 pressure treated joists spaced 18". The base of the sauna is 8'x6'6". Then I used 3/4" osb for the decking.
Step 2: Framing
The sauna uses a lean to design with the front being 7' and the back at 6'3". That will be enough to shed the rain and snow without being too tall in the front or short in the rear.
Step 3: Plywood Sheathing
After framing out the wall and securing the plywood, I cut out the door and window frames. I cut the window so that I would be able to look out of it while sitting on the back row and the door was cut at 26". It's a cozy door but I didn't want it to be large and have it take away from the cozy cabin look I was going for.
Step 4: Moving the Sauna and Adding Roof Joists.
After the framing and plywood was finished I rolled it into my alley with 3 1" steel pipes where I began coating the Sauna in tar paper and adding the roof joists. The roof joists came out to a 8.2 degree angle and I cut the "birds mouths" accordingly. The front and rear of the sauna have a double header which is likely overkill for such a small structure but it is easy and fairly inexpensive to make a small structure very very strong so I went for it.
Step 5: Adding Siding
For the exterior siding, I used pine beetle kill. The wood is beautiful and turned out better than I could have asked for. I chose 1x6 T&G siding and used 2" galvanized nails to blind nail all of the siding into the studs.
Step 6: Building the Door
To build a door, I chose to use the T&G to construct a "z batten" style door that has the look of a rustic barn door and is very solid. I ripped the tongue and groove off of the outermost pieces and then did the same for the diagonal and horizontal bracing. This might be my favorite part of the sauna. It turned out beautifully.
Step 7: Window Construction
The window was built by ripping the the bevel edge off of douglas fir 2x4s and then cutting a 1/8x1/8 slot in the frame to seat the three 8x10 glass sheets. This was mounted with hinges so to cool the sauna down when needed.
Step 8: Interior
The interior was built using radiant barrier, insulation and the 1x6 siding used on the exterior. The radiant barrier and blow in eco insulation keep it very warm. I installed the insulation by hand due to the small size of the job. After tacking up the radiant barrier and adding the insulation, the siding was nailed down. The pine on the itnerior has a great smell and feel to it. When you walk through the door, it has a very peaceful and soft feel.
In order to lower the clearance to combustibles, tin roofing was attached to the walls.
Step 9: 2 Month Review
I have used the sauna about 15 times now. It heats up to 150 in about 25 minutes so I'm really happy about how quickly it heats up. The stove is pretty large for the space and it actually charred some of the flooring so I had to raise it up on a layers of bricks and a stainless steel sheet to reflect the heat away from the flooring.
If I were doing it again, I would make it a bit larger so that I could have the stadium style seating in the sauna. I can't do two rows of seating because the bottom row would be way too close to the stove. It is working great though and comfortably seats four people.
Thanks for looking.
Step 10: Timber!
The sauna is in it's final spot near the creek. I had a tree fall on the deck over the winter but it was unscathed. The tree came about 2" from hitting the roof but no problems.
Just bucked the wood up and have a nice supply for the coming months.
26 Comments
Question 10 months ago on Step 9
How much bigger? 8x8?
Tip 2 years ago
I’m working with a guy who has built over 30 saunas over a twenty year period and he understands how important a breathable sauna is where the floors are open and there are two vents to create an air flow. We are located on 137 in Waldo. Also cedar benches and walls work best.
Reply 1 year ago
I'm thinking of making a sauna myself, I don't know terribly much but to my understanding it's the type of wood that makes the experience. I'm hesitant to use so many 2"x4"s and plywood because I figure it will ruin the scent from the nicer smelling woods like pine or cedar.
What do you think?
Reply 1 year ago
The 2x4s and plywood (osb) will be behind a vapor barrier so you won’t smell them at all. That’s also important for safety. You don’t want to heat up and smell the glue in the plywood (osb). The 2x4s would be fine to smell.
1 year ago
Fantastic! QQ: I'm thinking about making it a Finnish style where water is ladled onto heated rocks. This would be a big drainage prob with an OSB deck. Thinking of using rigid insulation between the floor joists slight angled for a drainage slope and then have cedar boards with 1/4inch space on top to let the water flow through the floor. Thoughts?
Question 2 years ago
Do you have detailed drawings of the sauna? I am looking to do something very similar in my back garden. Looks excellent - you must be very proud
Answer 2 years ago
Hi, unfortunately I don't have the plans anymore. I loosely built them off these floorplans https://www.kdpoolscapes.com/whatwedo_saunas.html
Question 2 years ago on Step 9
Cool build. Did you put the pine siding on the floor as well? If not what did you use? Also, did you insulate the ceiling as well?
Thanks,
Jake
Answer 2 years ago
I used the same tongue and groove for the inside and yes I did insulate the ceiling.
Reply 2 years ago
Thank you. I am researching a heating source and want to go wood. Did you go wood and if so, what stove did you choose?
Reply 2 years ago
Yes I went with wood. The stove doesn’t matter. Just find a used smaller one that fits the space. They’re capable of hearing 600 plus sq ft so they heat this tiny box fast! Make sure you put up metal with spacers behind it around the stove so you don’t burn your sauna down
Question 2 years ago
I am planning out building a sauna. Do you have a picture of the finished inside? What did you use for the flooring and ceiling, the same interior wood?
7 years ago
Does your pine walls weep sap? I'd rather pine than cedar, for a number of reasons, but I keep getting warned against it for sap reasons.
Reply 7 years ago
It does leak a little bit of sap but not much. Pine is much cheaper and from the research I did, that Is actually what the original Finish saunas were made out of. I am very happy with the pine.
Reply 4 years ago
I did it; an 8x8 shed with 6x1 pine tongue and groove inside and 2x4 benches. The sap is minimal and nowhere that matters. Thanks for the inspiration.
I turned my wood stove into a rocket stove, which helped a lot with lighting and heat generation. I put a 6" hole in the top front to draw in the air. On top of the stove I put a garbage can. The stove pipe goes into the can, stopping about four inches from the top. About six inches from the bottom another stove pipe exits the can and goes up and out of the sauna. The bottom six inches of the can are packed with gravel. Then I put the lid on.
In brief, the air rushes in through the top (rocket) and generates an immense heat with little fuel. As the stove pipe, can and gravel heat up the fire gets more efficient. By the time it exits the can, there is little smoke. From outside it is hard to tell the fire is even lit.
Reply 2 years ago
You have any pictures of your woodstove to rocketstove conversion?
Reply 3 years ago
Wow that's an awesome stove solution. I may use that on my next build. Pictures?
Reply 3 years ago
I've heard most garbage cans are made of galvanized steel, which can off gas zinc when temps get high. This can cause metal fume fever. You might want to invest in a 55 gallon metal drum and burn off the paint before using it.
Question 4 years ago on Step 8
Great Sauna. We have some off grid property we'd like to build one on. I really like your idea of pre-fabbing it at your house. Did you have to take it apart to get it to the site?
What does the interior look like and what are radient panel insulation. I'm not familiar.
7 years ago
how much did this cost about?
thanks