How to Set Up a DIY Outdoor Sauna (In 13 Easy Steps!)

sauna accessories

The benefits of using a sauna have been repeatedly proven by many scientific studies. From relieving stress and relaxing your muscles to soothing any aches or pains you might have in your muscles and joints, this practice has been present for centuries in some cultures. If you’re considering having your own, read on to find out how to set up a DIY outdoor sauna.

DIY Outdoor Sauna – Building One Step by Step

1. Choose the Right Spot

The first thing you need to do is to make sure that you have enough space in your backyard for the DIY outdoor sauna. A level and rather secluded spot next to the home would be ideal. Many people choose to set up the sauna in an old backyard shed they’re not using anymore, for example. An exterior sauna is a great idea since it comes up with the best scenery, ventilation, and sustainability. However, you need to make sure that you can get easy access to plumbing, heating, and electricity. Moreover, there shouldn’t be any overhanging trees or running water in the area.

2. Install the Lines

Next, you need to install any necessary wires, pipes, or gas lines. It would be better to ask for help from a professional instead of risking anything.

DIY outdoor sauna couple relaxing in the sauna

3. Allow Space for Rocks

One option would be to use lava rocks to heat the sauna, which are heated in a stove and then poured water over them to make some steam. In this case, you need to dig some space for them. In case of using infrared heating, you should make sure there is enough power for the entire heating system to run smoothly. For this, you need to install a heater inside your DIY outdoor sauna. Usually, these are the two most common ways people choose to heat their personal saunas. If you’re looking for an ecological option, you should consider using an energy efficient wood-burning stove.

4. Pour the Foundation

In case you are not using a space that has been already built, you will need to pour the foundation first. A three-inch layer of concrete should be more than enough, but feel free to adjust this as you wish.

5. Set Up the Frame

The frame of the sauna typically consists of a simple structure made with wooden boards. Recycled cedar is a good option for those who want to build an ecological sauna. It’s important to leave some room for three main ventilation points: one above the heater you will use, one in the ceiling, and one in the floor. However, make sure the ceiling height is no taller than 7 feet and allow for a small drain on the floor. Keep in mind that you should leave some space for windows and benches. Naturally, there are plenty of ways you can go about the structure, depending on how much space you have available, how many people will be using the sauna, etc.

Luckily, there are plenty of online resources to help you with that. Look for free sauna building plans and see what fits your needs best.

DIY outdoor sauna in the woods

6. Insulate the Frame

Now, the inner frame needs to be insulated with fiberglass. It’s also time to add a vapor barrier that will keep the fiberglass away from moisture. This means that it will last much longer. It is recommended that you insulate the walls with an R13-rated insulation. For the ceiling, you should use R22 – R26. Next, staple over some sauna aluminum foil to act as a vapor barrier.

7. Build the Outer Wall and Roof

The next step is building your own DIY outdoor sauna is to take the wood and build an outer wall set about a foot outside the inner frame you previously built. Use simple wood and tile for this, and keep in mind to leave a ventilation spot open for the steam to get away.

8. Install the Heating System

Depending on the heating system you chose, it’s time to install it. Usually, any system comes with its own instructions, which is why you should pay attention to them. Make sure you leave a wide space for the sauna heater.

DIY outdoor sauna setup

9. Set the Flooring

The next step you need to take to build your own DIY outdoor sauna is to set the flooring. Use a layer of ceramic tiles. They are useful because they will go over the heating system and thus collect moisture.

10. Add the Second Layer of Flooring

For the second layer, you should use unsecured boards. Leave them unsecured to ensure easy access beyond them. You should be able to remove them and get to clean the tiles.

11. Install the Heater

Add the heater to the room. Make sure it’s placed under one of the three main ventilation spots we mentioned earlier.

12. Add Fixtures

One of the last steps you need to take to complete your DIY outdoor sauna is to add the fixtures. Add the windows, benches, and any other items you wish. However, make sure they are resistant to high temperatures and humidity, otherwise, you may need to buy some new ones sooner than you think.

13. Test the Sauna

The final step is to test the sauna. Turn on the heating system and see if and how the ventilation points work before you start using it. See if there are any issues with the insulation or the placement of the room.

DIY outdoor sauna round sauna

Common DIY Outdoor Sauna Mistakes

Just like with the rest of the DIY projects, there are many things that can go wrong here. Luckily, we gathered some of the most common mistakes people do when setting up their DIY outdoor sauna so you won’t ruin the entire project unknowingly.

1. Don’t Use Infrared in Winter

An infrared sauna is a perfect choice for using outdoors in summer, or for a normal use at an indoor room temperature. However, it’s a mistake to use them during winter when it’s very cold. They are not designed to stand very low temperatures by default, so you might even waste your money on such a device. Of course, if you live in a warmer area, this might be a good solution, but you should still check before purchasing it.

2. Don’t Use a GFI or GFCI

It’s never a good idea to use a GFI or a GFCI on your electric DIY outdoor sauna. GFI stands for ‘ground fault interrupter’ and it should protect you from an electrical shock when there occurs a difference in the currents. As such, whenever you’ll throw water on the hot sauna stones, the device will trip. Instead, make sure that all the electrical installations are set up correctly and safely.

3. Not Checking with the Authorities

Before getting down to building your own DIY outdoor sauna, it’s recommended you check with authorities. First, if you’re making a custom size sauna, you might want to keep it under 100 square meters. Anything bigger than that is usually considered a building and you need to obtain a permit to build it. Second, in case you are using a wood-burning rock sauna heater, you should have the chimney inspected by a local authority.

DIY outdoor sauna wooden sauna interior

4. Don’t Use Wooden Floors

It might seem obvious, but there have been cases where people installed a wood-burning rock heater over a concrete patio slab, over a wood floor. The heaters are very efficient in general, so they can heat up the concrete patio stone and then ignite the wooden sauna floor. This can even happen 8 hours later, so pay attention to this.

5. Don’t Use Bad Sauna Lights

If you connected your sauna to the electrical system, it’s a good idea to use 2 wall light fixtures to light it up. It’s preferable you choose some heavy-duty ones that have special gaskets for surface mounting. Two lights should be enough for a small sauna. However, avoid ceiling pot lights for your DIY outdoor sauna at any costs! Installing them means not insulating around the pot due to the heat buildup, and your sauna needs to be well insulated everywhere. If you’re living off the grid, a solution would be to set a coal oil lamp on a small window shelf.

6. Don’t Store Things There

Just as we previously mentioned, the room constantly goes through extreme temperatures and humidity, which is not a good environment for things like clothes, decorations, books, etc. If you want to keep some entertainment items there, it might be good to have a separate room for it. Or you can simply fetch them from your house when you want to spend some time in the sauna.

Here you can see a clip suggesting one way of building a sauna by yourself:


It’s not difficult to set up your own DIY outdoor sauna if you follow the steps above. However, keep in mind that it may take quite a while, not to mention the investment you need to make in the right materials. Other than that, remember to check with the local authorities if you’re planning on a huge sauna or talk to an electrician if you want to make sure you installed electrical systems correctly.

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