Build a Weatherproof Sauna Outdoors

Wish you had your own personal sauna oasis? You're not alone. There's no denying the appeal of a DIY sauna bath at home, where you can relax in your own garden.

But why choose an outdoor sauna? Simple: Mold and water can ruin indoor saunas and possibly do a lot of damage to your home. A standalone outdoor sauna is a better choice because it keeps these dangers away from your home.

But there are some things that can go wrong when you try to construct a DIY sauna bath at home. If you're not careful, you could waste a lot of money on a subpar sauna. Imagine spending thousands of dollars on benches that aren't comfortable or a space that you don't like. You deserve better! Here's how to build a safe, weatherproof outdoor sauna that is worth every penny.

Step 1: Pick a Location and Size

When constructing a DIY sauna bath at home, find a flat area near your home that gets plenty of sunlight and is close enough for electrical connections, and make sure to keep everything in a waterproof box.

Also, it's a good idea to stay away from windy places to keep dust and debris from causing problems. Finally, placing the sauna on a southern wall can help protect it from the harsh winter snow and blizzards.

When figuring out the size of your sauna, try to make it at least two meters long so there's enough space to sit and lie down comfortably. Keep a height of two meters for the best heat distribution. Consider adding a false ceiling to help keep the heat in and spread it around better.

Step 2: Gather Your Sauna Building Materials

1. Ventilation:

• Aluminum foil and aluminum tape
• 7.5 centimeter pipe for outgoing ventilation

 

2. Insulation:

• Foam panels. (100mm for walls, 200mm for the roof)
• Aluminum foil

 

3. Interior Paneling:

• Tongue-and-groove spruce planks for the interior walls.
• Paraffin oil for treating the wooden benches.

4. Building Structure:

Wood for framing, such as spruce for the front panel and benches.
304 stainless steel screws for fastening the wooden structures together.

5. Windows:

• Custom-made glass for the window with a tint.
• Silicone for sealing the glass window.

6. Heater and Rocks:

• A freestanding heater with ventilation pipes for fresh air intake and hot air exhaust.
• Lava rocks (+-100 kilograms)

7.Bench Materials:

• Solid bench structure made of boards.
• Lighter wood with low density for bench tops.
• Mounting brackets or 304 stainless steel screws for overall bench construction.

8. Additional Materials:

• Staple gun for securing insulation
• Mesh for covering ventilation

Step 3: Sauna Floor Construction

When it comes to a good sauna floor, there are a few important things to keep in mind. You want a non-slip surface to keep everyone safe, warmth under bare feet for comfort, and a way for water to drain efficiently to handle all that post-sauna sweat.

When you're designing your sauna floor, it's super important to think about insulation, heating, and the slope of the floor.

When you're picking materials for your sauna floor, think about going with wooden floors. They're great for outdoor saunas because they insulate well and can be treated to resist water. 

Outdoor sauna structures do well with wooden floors that have a bit of a slope and good ventilation to help manage moisture.

Step 4: Ventilation

Make sure there's good airflow by setting up an air intake close to the heater and a way for the hot, humid air to get out. Try using a pipe system to help control the airflow and keep moisture from building up inside the sauna.

Step 5: Sauna Wall Construction

Put together the sauna walls with insulation panels that can handle high temperatures. It's best to avoid polystyrene insulation that can't handle heat. Use string and a staple gun to hold the panels in place for a tight fit.

Step 6: Insulation

Insulate the walls and ceiling using foam panels that are the right thickness, like around 10 to 15 cm. Wrap the insulation in aluminum foil to keep moisture from getting in. Seal the edges of the foil with aluminum tape to give it that extra protection. 

Step 7: Wood Paneling

Go for tongue-and-groove spruce planks for the sauna interior. Go for longer tongues on the planks to prepare for any shrinking that might happen due to heat. Use 304 stainless steel screws to attach the planks for a secure and nice-looking finish.

Step 8: Heater Installation

Pick a heater that has the right power output for the size of your sauna. Try to get about one kilowatt of power for every cubic meter of space you want to heat so you can keep things nice and cozy. Stack lava rocks in the heater to help spread the heat around better.

Step 9: Window and Door

Put in a window with insulated glass to bring in natural light. Seal the edges of the windows and doors tightly with non-acetate silicone. Check the sauna at high temperatures to see if there are any leaks in the sealant.

Step 10: Sauna Bench Construction

Create sturdy benches that have comfortable measurements. Make sure the top bench is about 60cm wide to provide extra comfort when lying down. Keep a distance of one meter between the top bench and the ceiling for the best seating setup.

Step 11: Lighting

Select suitable lighting fixtures that can endure the high temperatures of the sauna. Place the lights strategically to make sure the whole sauna is lit up evenly. Consider using lighting options that can resist water for extra safety.

Is It Safe To Have A Sauna At Home?

Yes, having an outdoor sauna at your home is usually safe, and in a lot of ways, it can actually be safer than having one indoors.

Outdoor saunas come with numerous benefits when it comes to safety and practicality. You'll never have to worry about moisture damage to your home's interior and the chances of mold growth in your living space. Also, outdoor saunas provide better natural ventilation options.

However, there are still safety considerations for a DIY sauna bath at home.

1: Electrical Safety:

• Always hire a licensed electrician for any wiring work.
• Install ground-fault circuit interrupter (GFCI) outlets.
• Use electrical components rated for high-humidity environments.
• Ensure proper connections to avoid fire risks.

2. Ventilation:

 

• Install an inlet vent low behind the heater and an outlet vent high in the corner farthest from the heater.
• Proper ventilation prevents overheating and ensures a comfortable experience.
• Consider an adjustable vent for better control.

 

3. Materials:

• Use only materials approved for sauna use to avoid toxic fumes.
• Apply a water-resistant sealant to all wood surfaces.
• Consider stainless-steel fasteners to prevent rusting.
• Use tempered glass for windows and doors to prevent cracking under heat stress.
• Use 304 stainless steel screws. 304 stainless steel screws provide great corrosion resistance in the high-humidity environment of a sauna, keeping everything strong and intact for a long time.

4. Temperature Control:

• Install a thermostat to regulate temperatures precisely.
• Ensure the sauna doesn't exceed its maximum temperature.

5.Fire Safety:

• Remove flammable items from the heater area.
• Place a smoke detector near the heater.
• Ensure proper clearances around the heater as specified by the manufacturer.

6. Heater Size and Installation:

• Choose the appropriate heater size for your sauna space.
• Use only UL-listed electrical components and heaters.
• Read and follow safety manuals for clearance guidelines before installing the stove.
• Ensure proper placement of the stove and include barriers between the stove and seating areas.
• Use only appropriate sauna rocks; random rocks can be safety hazards and may damage your heater.

7. Floor Design:

• Slope the floor slightly towards a drain for water runoff.

8. Layout and Construction:

• Prioritize function over form in sauna design.
• Be aware that large windows and glass doors can lead to significant heat loss, especially in outdoor saunas.

9. Professional Assistance:

• Ensure your contractor understands the concept of sauna construction before hiring them.

• Consult with sauna experts or experienced professionals for guidance.

What Type Of Wood Is Best For A Sauna?

If you're thinking about building a DIY sauna at home, choosing the right wood is vital for making sure it lasts, is comfortable, and gives you a great experience. When it comes to sauna construction, Western Red Cedar and Hemlock are definitely the go-to options, but there are a few other choices that are also interesting to consider.

Top Choices: Western Red Cedar and Hemlock

Western Red Cedar: This high-quality wood is valued for its natural ability to resist decay and bugs, great insulation features, and lovely scent. Cedar stays cool to the touch, which makes it perfect for sauna benches. Cedar also heats up more slowly, ensuring a comfortable environment.

Hemlock: Hemlock is a great choice if you're looking for something other than cedar. It's durable, stable, and doesn't expand or contract much, which is a nice bonus. It's a bit easier on the wallet compared to cedar, plus it has a nice, consistent texture and a pleasant aroma.

Other Good Choices for Wood for Sauna Construction at Home:

Thermo-Spruce: Thermo-Spruce is heat-treated spruce that provides better dimensional stability and decay resistance, making it a great option for saunas.

Basswood: Basswood is a great choice if you have sensitive skin. It has natural antifungal properties and stays cool to the touch, making it quite comfortable to use. It's really soft, super durable, and does a great job even when things get hot.

Aspen: It's lightweight and budget-friendly, making it a popular option for saunas in both Europe and North America. It's got a light color and a nice, subtle aroma that’s really pleasant. Just like cedar, it's perfect for sauna benches since it stays cool to the touch as the temperature goes up.

Alder: Alder is another softwood choice that does a great job in high-temperature settings.

Scots Pine: Scots Pine is a classic pick in Nordic countries, celebrated for its long-lasting nature and lovely aroma.

When you're building your DIY sauna bath at home, keep in mind that 304 stainless steel screws work well with all the types of wood we've talked about and are perfect for the assembly process. These screws are great at resisting corrosion in humid environments, so your wooden structures will last longer no matter what type of wood you go with.

Is It Cheaper To Build Or Buy A Sauna?

When thinking about whether it's more affordable to build or buy a sauna, the answer really depends on a few things, like how good you are at DIY, how much time you have, and what exactly you need. 

Creating a DIY sauna bath at home can save money and lets you personalize it, but it does take a lot of time and skills. Getting a ready-made sauna is super convenient, and you know it’s good quality, but it does cost more at the start. A common choice is to use outdoor sauna building kits, which are easy to put together, budget-friendly, and allow for some customization.

Typically, making your own sauna from scratch is the least expensive option, costing about $2,000 to $6,000. Next up are outdoor sauna building kits, which range from $4,000 to $8,000. Finally, pre-built saunas are the priciest, with prices starting at $5,000 and going over $15,000.

Are Home Saunas Worth It?

Home saunas can be a smart choice, providing savings over time when you think about how much you would spend on regular trips to the spa.

Even though there are some upfront costs for building a DIY sauna bath at home, the ongoing expenses are pretty low, mainly just the electricity needed for heating. To make sure your sauna lasts a long time and stays valuable, it's important to use good materials, especially 304 stainless steel for sauna screws.

304 stainless steel screws are made to handle the high-moisture conditions of a sauna and the outdoor elements. If you use strong materials and good building methods, you can make a sauna that can handle the weather and last a long time. It will give you a relaxing, private place to relax in your garden for many years.