Can I paint or stain the inside of my sauna?

Do you paint the inside of a sauna? That's a perfectly valid question, and you're probably also thinking about the long-term durability of your wellness oasis. From this perspective, of course, it makes sense to protect the wood from moisture and contamination as best as possible.
Can the interior of my sauna be painted or stained?

Can I paint or stain the inside of my sauna?

No, the interior of saunas should not be stained, painted or varnished. The reason for this is due to the way the sauna works and the properties of the wood.

The wood used in saunas is usually untreated and natural. This allows the wood to absorb and release moisture, which is crucial for a healthy sauna climate. The wood in the sauna regulates humidity and temperature by absorbing moisture and releasing it when needed. Painting or staining the wood would interfere with this natural ability, as the coating could seal the wood’s pores and disrupt moisture regulation. This could lead to undesirable effects such as cracking or warping of the wood.

In addition, painted or varnished surfaces in the sauna may release gases or fumes that could be harmful to users. Heat and humidity in the sauna could activate the chemicals in the paint or varnish and release harmful substances.

To prevent the growth of germs, fungi or mold, keep the interior surfaces of the sauna clean. Regular cleaning and airing are crucial in this regard. However, with proper selection and treatment of sauna wood and proper use of the sauna, the growth of germs or mold should be largely preventable.

Can I seal the wood?

Special paraffin-based oils are available commercially that are particularly suitable for treating sauna benches. These oils are specially designed for use in saunas and provide effective protection against moisture and dirt.

These oils have the property to penetrate deep into the wood and protect it from the inside. This makes the wood more resistant to the effects of moisture and discoloration. A protective layer forms on the surface of the wood, preventing dirt or liquids from penetrating and damaging the wood.

Before applying the oil to the entire surface of the sauna benches, it is recommended to perform a test in an inconspicuous place. In this way, you can ensure that the oil will achieve the desired result and will not undesirably change the color of the wood.

The application of kerosene oil is relatively simple. It is recommended to apply the oil evenly and thinly on the surface of the wood. A soft cloth or brush is suitable for this purpose. The oil should then be allowed to absorb and dry for about an hour, so that it can develop its protective effect.

After the oil is sufficiently absorbed, you can wipe off the excess oil with a damp towel. This will ensure that no oily or sticky surface is left behind. Be sure to remove the excess oil thoroughly to avoid a slippery feeling on the sauna benches.

Be sure to use the oil only on freshly washed and spotless sauna surfaces. Make sure the sauna benches are free of dust, dirt or other contaminants before applying the oil. Careful cleaning prior to oil treatment will ensure optimal adhesion of the oil to the wood and an even result.

It is also important to follow the manufacturer’s instructions and take proper safety precautions. Read the application instructions on the packaging carefully and follow all warnings and recommendations.

Regular oiling can extend the life of your sauna benches while maintaining their beauty and functionality. Treating the wood with oil protects it from moisture and dirt and ensures that your sauna is always in top condition.

To use kerosene oil for your sauna benches

  • Heat the sauna and the oil to a temperature of 40 degrees Celsius. The heat will open up the grain of the wood, making it easier to absorb the oil.
  • To distribute the oil evenly, use a sponge or brush. Be sure to oil both sides of the benches to prevent cracking.
  • Apply the oil evenly to all wood surfaces.
  • Allow the oil to soak in for 1 to 2 hours.
  • Wipe away any oil residue with a lint-free cloth.
  • Check that the oil has been fully absorbed before heating the sauna again.

What is kerosene oil?

Kerosene oil, also known as kerosene wax, is a widely used and versatile oil that is used in a variety of applications. It is a clear, colorless and odorless liquid composed of a mixture of saturated hydrocarbons.

In sauna care, pure kerosene oil is a popular option for treating wooden surfaces such as sauna benches or wood paneling. Due to its non-toxic properties, it is safe for contact with the skin, and no unpleasant odors are produced during application.

Kerosene oil offers a number of advantages for the care of wood in the sauna. It penetrates into the pores of the wood and forms a protective layer that protects the wood from moisture, dirt and premature wear. This protective layer helps to protect the wood from the influence of temperature and humidity fluctuations that may occur in the sauna room.

Especially in thermally treated wood, which is used in many saunas, kerosene oil shows its advantages. Treatment with kerosene oil protects the wood, preserves its natural beauty and prevents it from drying out or warping.

The application of kerosene oil on wooden surfaces is relatively simple. It is recommended to apply the oil evenly with a soft cloth or a brush and then let it soak in for some time. The wood absorbs the oil and is thus cared for and protected. Excess oil can be removed with a clean cloth.

Tip after the sauna session

After the sauna session, it is recommended to wipe the benches thoroughly to remove excess moisture. Wiping down the benches not only keeps the sauna clean, but also improves the durability of the wood. Moisture can damage the wood over time, so it is advisable to clean the wood regularly.

In addition to cleaning the benches, it is recommended to leave the sauna doors open. This allows for better ventilation and promotes drying of the sauna room. The open doors allow air exchange, which makes the residual moisture evaporate faster. This allows the sauna to dry quickly and be ready for the next use.

In addition, opening the doors can also help reduce unpleasant odors. Air circulation minimizes the formation of mold or other unwanted odors.


As a rule, people leave the interior of the sauna untreated. Nevertheless, if you are worried about the high-quality wood, the trade offers good alternatives. Be sure to look for quality and test seals, so that there are no nasty surprises later at the high temperatures! This is because conventional paints usually evaporate when exposed to heat. This is detrimental to your health in the long run. If you always pay attention to sufficiently good hygiene, the interior will not need any further treatment.


Buying tip: Harvia kerosene oil

When you use kerosene oil to protect wood surfaces, you can minimize the amount of liquid and dirt that can penetrate the wood. It also does a great job of bringing out the grain of the wood surfaces. Kerosene oil can be used on all wood surfaces, but it is especially suitable for heat-treated surfaces.

Angebot Paraffinöl, 500 ml


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