Introduction: DIY Outdoor Sauna
I wanted to share with you my outdoor Sauna build. It's inspired by a log cabin and simple to build. It took my 2 weekends to finish. Measurements are around 1500*1500*2000mm / 5*5*6.6ft. This build is suited for 1 to 2 Sauna guests. Overall, I kept the costs below 1000$ by using a 2nd hand stove and cheap timber beams.
- approx.100 wooden beams (1500*80*50mm) for the wall and ceiling
- 5 * 10mm steel rods with washers and nuts
- decking boards and wooden struts for the flooring
- concrete slabs
- Bitumen roofing felt
- planed planks and wooden struts for the bench
- wood burning Sauna stove (Harvia M3)
- steel chimney pipes
- Sauna door with glass
- 5m LED strip
- wood glue
- different kind of wood screws
- Tools: Flame scarfing device, electric drill, hammer, knife,...
Step 1: Groundwork
First, you need to do the groundwork. I decided to go for a simple foundation. Depending on the nature of the ground, you might need to go for a more stable solution like a concrete foundation.
- Excavate soil
- Fill with gravel
- Put concrete slabs in each corner flat on gravel
- Make sure that all slabs are at the same height and level
Step 2: Floor
Second, you need to do the flooring of the sauna. I used decking planks, as they are robust and good looking. Moreover, you can walk on them barefoot.
- Make a wooden frame; the frame is sized onetime the length plus the width of the beam; I used 1500*80*50mm beams, so my frame was sized 1550*1550 mm (1500+50mm)
- Screw the decking planks on the frame
- Cut the decking planks in size
Step 3: Walls
Now you need to build the side walls of the sauna.
- Drill holes at one end of the timber beams. The hole is for the steel rod which helps to align the beams.
- Make a template for the drilling (I used a thick steel plate). The hole needs to be drilled in the middle of the width of the beam half the width away from the end. I used timber beams with 50mm width. Thus I needed to drill the holes 25mm away from the end of the beam.
- Screw the first row of timber beams on the wooden floor. Make sure that at each corner as well as at the door opening a steel rod is inserted
- Stack the next layers on top using the steel rods and wood glue. In order to make the walls more stable stack the beams in an offset fashion. Overall, I stacked 24 rows
Step 4: Roof
For the roof I used the same timber beams as for the wall. However, I didn't drill holes.
- Screw the first beam on the top of the walls
- Connect the other beams by using wood glue
- Screw the final beam on top of the walls
- Cut bitumen felt roofing in size
- Put the bitumen felt on the wooden roof
- Use the flame scarfing device to glue it to the wood
Step 5: Exterior - Shou Sugi Ban
To keep a natural look I decided to go for a traditional Japanese technique for the exterior: Shou Sugi Ban. Basically it means burning the wood to increase its longevity and give it a cool dark look.
- I used the same flame scarfing device as for the bitumen roof
- WARNING! Be careful not to burn your Sauna to the ground! keep a fire extinguisher near you! After finishing keep an eye on your build to make sure that no fire starts!
Step 6: Door
The most expensive part of my Sauna build was the glass door. You can keep the costs down by using a wooden door.
- You should insert the door with a partner, as it is quite heavy (and glass tends to break)
- The door should open outwards
- Screw the doorframe to the walls
- Add hinge cover and door handle
Step 7: Interior - Sauna Bench
You can buy a Sauna bench but I wanted to create also the interior myself. In addition, it is cheaper and made to fit.
- Cut a frame in size. I used 2 longitudinal struts and 4 cross struts. The width of the bench should be around 600mm/2ft
- Use wood screws to assemble the frame
- Screw the frame on the wall. I put it at a height of around 600mm/2ft
- Use planed planks for the top. Screw them on the frame.
- Install a RGB LED strip for the lighting. You can remotely control the color which helps to create a cosy atmosphere.
Step 8: Interior - Sauna Stove
Now it's time for the most important part, the wood burning stove.
- Put a protective plate under the stove
- Mark the outlet of the chimney on the wall
- Drill a hole for the outlet in the wall
- Seal the connection between stove and steel chimney up
- Install the chimney
Step 9: Final Steps
Just a few steps are now missing.
- Add stones to the Sauna stove
- Install a thermometer/hygrometer and hourglass
- Tighten the screws on top of the steel rods
Step 10: Enjoy!
I hope you had as much fun reading my outdoor Sauna Instructable as I did building it. Maybe it inspires you to build your own Sauna. If you like this Instructable feel free to give it a like.