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DIY Sauna Safety: Essential Precautions to Take When Building Your Own Sauna

by Max
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DIY Sauna Safety - Essential Precautions to Take

If you’re someone who values their health and wellness, building a sauna in your home may be the best decision you can make. Saunas are excellent tools for self-care and can also add value to your property. With benefits such as relaxation, detoxification, and improved circulation – a sauna is an investment worth making.

However, certain sauna safety precautions should be considered before building your own. This is especially important if you’re new to DIY or haven’t worked with tools and materials like this before.

This article will cover everything you need to know about DIY sauna safety – helping you to build your sauna without worry.

Are DIY Home Saunas Safe?

When anyone considers building a sauna for the first time, safety is usually at the forefront of their mind. The short answer is yes – with proper preparation and caution, DIY home saunas are very safe!

It is important to be mindful of the potential risks that could arise if precautions are not taken.

Saunas have various features that can be dangerous if installed incorrectly, such as electrical wiring and heat sources. Understanding DIY sauna safety (and the mistakes to avoid) will help you build a safe and enjoyable sauna.

5 Common DIY Sauna Mistakes

There’s a good chance you’ll make some mistakes when starting any DIY project. Usually, it’s no big deal and can easily be rectified depending on the circumstances.

However, with saunas, specific mistakes can present safety issues. You’re working with incredibly high temperatures and possible fire hazards, so taking extra precautions is necessary.

Let’s take a look at some of the most common mistakes people make when building a sauna:

1. Not Having Adequate Ventilation

Ventilation is not technically required for infrared or electric-heated saunas, but it is a good precaution to take. Poor ventilation can cause temperatures to increase dramatically, which can cause dizziness or other health issues. If you have a wood-burning stove, you must have proper ventilation to prevent a build-up of carbon monoxide.

2. Not Picking the Right Location

Choosing the wrong location to build your sauna could cause both safety and practical issues. This means where you put your sauna is just as important as everything else. You should never put a sauna meant for the outdoors inside a building. There should also be enough room to install a door that swings outwards. Plus, the ability to install power outlets where needed.

3. Not Using the Right Materials

Materials are an essential factor when it comes to DIY saunas. You want something that’s heat-resistant, durable, and long-lasting. Using materials not designed to withstand high temperatures, such as plastic or other flammable items, could increase the risk of fire or even personal injury.

4. Not Following Building Regulations and Permits

When working on any construction project, you must adhere to the relevant building regulations and obtain the necessary permits. Different locations have different regulations, so make sure to familiarize yourself with the laws in your area. Not following these rules could lead to fines or even having to dismantle the sauna.

If you do need to apply for permits, be sure to allow time for the application process. Depending on your local government’s timeline, this could take a few weeks or even months.

5. Not Using Insulation or Vapor Barriers

Insulation keeps heat in the saunas, and vapor barriers keep water out of your home. Without insulation, you’ll find that the sauna’s temperature will decrease quickly, and your experience won’t be as enjoyable. And without vapor barriers, moisture can seep into the walls, leading to dangerous mold growth.

Essential DIY Sauna Safety Precautions to Consider

Crafting a DIY sauna is more than just building a structure and choosing the best heat source.

Safety should always be your priority when building and operating a sauna. Whether you’re using a prefabricated sauna kit or creating your own from scratch – it’s essential to consider what precautions you should take.

Choose the Right Size Space

Your DIY sauna should ideally be 7 feet high for adequate heat distribution. Heat rises, so having a higher ceiling than this will mean the hottest air will gather at the ceiling. This will make your sauna less efficient in terms of heat and energy consumption.

Having the right-sized space also allows the air to circulate properly. If the room is too small, it can become stuffy, which could be uncomfortable and potentially hazardous. A traditional sauna for up to four people typically measures 6×8 feet.

The size of your DIY sauna will depend on how many people will use it and the available space.

Install Proper Ventilation

Ventilation allows air to move freely in and out of the sauna as required. Not only is this important for user safety, but also for the maintenance of your sauna. Having the ability to air out your sauna between uses helps keep it fresh and hygienic.

You can choose between natural and mechanical ventilation for your sauna. Natural ventilation involves installing a specific hatch/chimney, while mechanical ventilation can be achieved using an exhaust fan. The type of ventilation you will use entirely depends on the heat source in your sauna.

Infrared and Electric Heated Saunas

Place an intake vent below, or as close as possible, your sauna heater. Then, you need to install an extraction vent on the opposite wall. The extraction vent should be around 6 inches from the ceiling level. The intake vent pulls in fresh air, while the extraction vent removes hot, stale air.

The only issue with this ventilation system is how it can affect the internal temperature. If your sauna is outdoors on a particularly cold day, it may not heat as quickly. In this case, you can close the extraction vent while the sauna heats up and open it when it feels a little stuffy.

Wood-Burning Saunas

For safety, you should only ever use wood-burning stoves in outdoor saunas. This is because the potential fire risk is much higher, and any smoke the fire creates should be directed outdoors. Wood-burning saunas also need a lot of air to work. As the fire burns, it will use up the oxygen in the room.

You must have an adequate ventilation system installed when using a wood-burning stove.

Chimneys or air pipes near the stove can help replenish the room’s oxygen and allow fumes to escape. Traditional Finnish saunas also often feature a 4-inch gap under the door to allow fresh air in and hot air out. This helps keep the environment safe for users and the sauna at a comfortable temperature.

Use a Control Unit or Thermostat

As per the UL Safety Standard (UL 875), all saunas in the USA should never exceed 195°F (90°C). If you have bought a UL-certified heater, then it should be programmed not to exceed this temperature. But, while this is a good safeguard, you should always have a control unit installed in your DIY sauna as a precaution.

A control unit works like a thermostat, allowing you to set the temperature and monitor it easily. A control unit can also be used to turn the sauna off, either in an emergency or when you’re finished using it. Some units also have a ‘safety switch’ that automatically shuts your heat source off.

A wood-burning stove can’t be controlled with a control unit, so installing a thermostat is the best way to ensure user safety.

Ensure the Foundations are Level

Unless you’re incorporating a drainage system, which should be done by a professional, the floor of your sauna must be level. An uneven foundation could cause tripping hazards and, in some cases, make the sauna structurally unsafe.

To check for an even floor, lay a long spirit level across the entire area. If you are building a DIY sauna outside, a good precaution would be to create a concrete foundation or use pavers to create a level platform.

Hire Professionals When Needed

To prevent any possible safety issues in your DIY sauna – you must know when to get help. Most sauna heaters require 220v power. This may need specialist hardwiring to work with a separate breaker in your home’s electric panel.

A professional should always undertake any electrical work, rewiring, or drain installation. If in doubt, it’s best to call in an expert to ensure everything is done properly and safely.

Read Prefab Reviews

Premade, ready-to-go saunas can be a safety godsend for DIY sauna builders. If you’re considering buying a prefabricated kit, always do your research and read customer reviews first. If you want a reliable, safe sauna, it’s important to make sure that the kit you have chosen is of good quality and comes with clear instructions.

Install Waterproof Flooring

Regardless of the type of sauna you have, waterproof flooring is essential. As the temperature increases and water is poured on hot rocks, condensation will form, which can cause damage to your floors. This is why you must choose a waterproof flooring option for your DIY sauna.

Good options include ceramic tiles, natural stone, or cement flooring. Choose a finish that is slip-resistant and easy to clean.

Under no circumstance should you ever use carpet in a sauna. Carpet is highly susceptible to mold and mildew growth and is a flammable material – a safety concern you want to avoid in your DIY sauna.

Use the Correct Wood

Not all wood is suitable for use inside a sauna. Softwoods like pine, spruce, and cedar are ideal for making saunas. You want to use a softwood that can handle high temperatures without splitting or warping. Hardwood, like oak and teak, is unsuitable for saunas as it’s more likely to warp when exposed to heat. Plus, they can start to smell over time and grow mold or fungi.

You should also avoid pressure-treated wood in your DIY sauna. As the name suggests, this type of wood has been treated with chemicals to protect it against rot and decay. Unfortunately, these chemicals can be toxic when exposed to heat, so this type of wood is unsuitable for saunas.

Fit the Door Correctly

The sauna door isn’t often top of mind for DIYers, but it’s an important safety consideration to make. You want to install your door to open outwards, not into the sauna. This is because if you ever need to make an emergency exit, it’s better to have the door open outwards.

Your sauna door should also never have a lock installed. Locks can fail in extreme heat, and a locked door could cause severe consequences in an emergency.

A well-fitted, outward-opening sauna door is an essential safety consideration for any DIY sauna.

Work With Quality Tools

You want to use quality tools and materials when building your own sauna. Cutting corners with cheaper products may be tempting, but this can have serious safety implications. Poorly fitted features, like a door or bench supports, can lead to accidents in the sauna if they give way.

Using quality tools and materials also means your DIY sauna may last longer, so it’s a worthwhile investment.

Properly Insulate and Vapor Seal

Before fitting the inside panels of your sauna, you should always insulate the walls and ceiling. This helps to keep the heat in and reduce noise levels. Fiberglass wool is the best type of insulation for a DIY sauna – it’s cost-effective and easy to fit.

You should also vapor seal your DIY sauna to protect your home. As you pour water on the sauna stones, vapor will escape from the unit. Without a vapor seal, this steam could potentially seep into your home and cause water damage or mildew growth.

Foil vapor barriers help keep the steam in and moisture out, so it’s an important safety consideration.

Always Use Stones on Your Stove

Whether you have an electric or wood-burning stove, stones should always be used. Stones help spread the heat evenly and can also take the brunt of any water you pour on them, protecting your heater from damage.

New stones should be cleaned with fresh water before first use and lay evenly across the top of the stove. If you ever notice damage to the rocks or your heater, you must replace them immediately.

Never Use Extension Cords

Your electric stove or infrared heat source should have a dedicated outlet for sauna use. Don’t be tempted to plug the device into an extension cord, as they can surge and spark.

Also, if you’re ever tempted to use a power bar to plug in your sauna heater – don’t. Power bars are not designed to handle the high wattage of sauna stoves and can present a serious fire hazard.

Secure Your Heat Source

Some sauna stoves are wall-mounted, so you will secure them in place without a second thought. You may not have the same consideration with a freestanding stove. Unless you specifically bought a portable stove, it is important to anchor your heat source.

Doing this prevents any safety mishaps, like the stove accidentally upturning or moving while in use.

Consider a Stove Guard

You should consider investing in a stove guard for your DIY sauna if you have a younger family or pets. This simply acts as a barrier to the stove, preventing anyone from accidentally touching or burning themselves.

It is an optional safety measure but one worth considering if you’re building a sauna at home. After all, the heater can remain hot for a long time after use.

Always Abide by Local Regulations

Rules, regulations, and permits are there for our safety. Yes, they can be a nuisance if they interfere with your DIY plans, but you must follow them to stay within the law and keep yourself safe.

Permits are often required to install electricity, plumbing, or gas-related components in your home. It’s also important to abide by building codes – these often cover things like insulation and electrical wiring. Plus, if you’re using a wood-burning stove in your DIY sauna, you should ensure you have the right permits for wood-burning appliances.

Ignoring safety regulations is not only dangerous but also illegal. Always check your local regulations before starting any DIY sauna project.

How to Safely Use a DIY Sauna

It isn’t just the building process that requires safety precautions – using your new sauna does too.

To ensure you reap the health and wellness benefits of your sauna without any risks, here are some safety guidelines you should follow:

  • Check that the temperature does not exceed 195°F / 90°C: Anything more can cause health risks.
  • Slowly increase your tolerance: Start by using the sauna for just 5 minutes, and build up your tolerance over the following weeks.
  • Keep hydrated: Saunas cause you to sweat, which can be dehydrating. Drink water before you get in the sauna and again after to replenish lost fluids.
  • Avoid using alcohol: Never drink alcohol before and while using a sauna; it can impact your ability to regulate heat.
  • Limit your time to 15-20 minutes: No one should stay in a sauna for longer than 20 minutes.
  • Monitor how you feel: Listen to your body and take a break if you feel dizzy or unwell.
  • Take a buddy: Using a sauna with someone else is always safer. That way, if something happens, help is at hand.
  • Take off your jewelry: You don’t want your metal jewelry to heat up and cause you discomfort in the sauna!
  • Wear appropriate clothing: A swimsuit or simply a towel is all you need to wear when in a sauna.


Are DIY saunas fire hazards?

When properly built and maintained, saunas are a safe place to unwind after a long day. Always check for potential issues, like wear and tear to the stove, before use. Never use a wood-burning stove in an indoor sauna.

Do saunas affect the temperature of your home?

Indoor saunas must be properly insulated and vapor-sealed to prevent steam from entering your home. This helps to regulate your home’s temperature – meaning you don’t have to worry about the sauna affecting it!

Can saunas flood?

There’s no possibility of your sauna ever flooding. The only water in a sauna is the water you pour on the stones to create steam. This water is only a small amount and not enough to flood your sauna.

Can I use an extension cord with my sauna stove?

No, you should never use an extension cord with a sauna stove, as it can cause serious fire hazards. Your infrared heater or electric stove should have a dedicated outlet.

Are there any age limits when using a DIY sauna?

Children over the age of 6 can safely use a sauna. However, exercising caution and supervision when using a DIY sauna with young children is important. Allow them to build up their tolerance first, and never let a child stay in the sauna for longer than 15 minutes. Always ensure children hydrate before and after, and never let them use a sauna alone.

What should I do if the temperature of my DIY sauna exceeds 195°F(90°C)?

It is essential to never exceed a temperature of 195°F (90°C) in your sauna. You’re best choosing a UL-certified heater to ensure this doesn’t happen. Having a control unit or thermometer can help you keep an eye on the temperature so it never goes too high. If it does, switch off the heater and allow your sauna to cool down before using again.

Final Thoughts on DIY Sauna Safety

DIY saunas can provide a place of relaxation away from the hustle and bustle of life. Keeping your sauna safe is simple so long as you follow the appropriate DIY sauna safety measures. With the right precautions and an understanding of how to use your DIY sauna, you can safely enjoy all its wonderful benefits!

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