How do I look after the wooden surfaces in the sauna?


The care of the wooden surfaces in a sauna is a task that requires attention and care. It is through proper maintenance that these elements can enjoy their natural beauty and warmth for many years. The purpose of this article is to discuss how to take care of the wooden surfaces of the sauna immediately after the sauna has been built, after the process of using the sauna, and as part of regular, planned care. Our guide will help you to protect the wood from fungi and mould, which can damage its structure and affect the aesthetics of the sauna.

Care of wooden surfaces immediately after the sauna has been built


The first step after the sauna is completed is the careful cleaning of all wooden surfaces. In the course of the construction work, they can become covered with dust, chips and other debris which need to be removed. For this task, it is best to use a soft brush or a hoover with a suitable attachment. It is important not to use hard abrasive tools for this purpose, which could damage the wood.

Surface protection

Once the surfaces are clean, we can move on to the protection stage. Choosing the right protective agent is crucial – its purpose is not only to protect the wood from moisture, but also to prevent the growth of fungi and mould. To do this, it is best to consult the sauna manufacturer or a wood care specialist, who will be able to advise on the most suitable product. Please note that different species of wood may require different types of protection.

The application of the protectant should be carried out in accordance with the manufacturer’s instructions. This usually involves using a brush or sponge and spreading the product evenly over the wooden surface. It is important to protect all parts, including the less visible parts.

Taking care of the wood in the sauna

Care of wooden surfaces after sauna use


After each use of the sauna, the wooden surfaces may be covered with sweat, oils or other residues which should be removed. To do this, use a soft cloth and a neutral detergent such as mild soap. Avoid using aggressive detergents, which can damage the wood surface or leave unsightly stains.


Regular use of the sauna can lead to a gradual disappearance of the protective layer on the wood. Therefore, it is worth checking after each use to see if it is no longer too thin or damaged. If you notice such signs, it may be necessary to apply a new protective layer. In addition, polishing the wood with special products for this purpose will help to restore its natural shine and keep the aesthetics of the sauna at a high level.

Regular scheduled maintenance to protect the wood and prevent fungal and mould growth

Weekly care

Weekly maintenance of the wood consists primarily of checking for any stains, fungi or mould on the surface. It is also a good idea to regularly remove dust and dirt from the wood with a soft cloth. Remember to ventilate the sauna well after each use – this helps to avoid moisture build-up, which promotes fungal growth.

Monthly maintenance

Every month, it is a good idea to check the condition of the protective layer on the wood more closely and renew it if necessary. This part of care should also include a deeper cleaning of the wood from residual oils and creams that may have dried out and formed unsightly tarnishes.

Annual care

Once a year, it is advisable to carry out even more intensive care. This involves deep-cleaning the wood with specialised fungus and mould removers. This is also a good time to carefully check the wood for any cracks or damages – if any appear, they should be repaired as soon as possible.

Remember, even if you visit the sauna infrequently, you should ventilate it periodically so that moisture does not build up.

Specifics of different types of wood and their care


Alder is particularly valued in sauna construction because of its natural resistance to moisture. This wood has a natural barrier against fungi and mould. However, for additional protection, the use of oils made from natural ingredients, such as Harvia sauna oil, is recommended. This oil protects the wood from moisture and dirt while enhancing the natural colour of the wood.


Osika is often used in sauna construction due to its softness and light colour. Due to its delicacy, cleaning should be done with a soft cloth and a gentle cleaning agent such as Supi Sauna Soap. In addition, Supi Sauna Sealant is recommended to protect the aspen wood.

Thermo alder

Thanks to the thermo-treatment process, thermo alder is more resistant to changes in humidity and temperature. However, due to this treatment, it requires a special protective agent to preserve its unique properties. Harvia Sauna Color agent, available in a variety of shades, is an excellent choice for protecting thermo alder.

Thermo aspen

The care of thermo aspen is similar to that of thermo alder. The most important thing is to use protective products designed for thermo wood, such as Harvia Sauna Color.


Linden, due to its delicacy, requires a soft cleaner and special care when cleaning. To protect Linden, it is recommended to use Supi Sauna Oil, which forms a protective coating on the surface of the wood.

Thermo Finnish pine

To protect thermo Finnish pine, it is recommended to use products specifically designed for thermo wood. In addition, the use of Supi Sauna sauna soap for regular cleaning is recommended.


Due to its natural essential oil, which is responsible for its characteristic smell, cedar is naturally resistant to fungi and mould. Nevertheless, it is recommended to use protective products such as Harvia Sauna Color for extra protection.


Spruce is a hard and durable wood species, but needs regular protection with Supi Sauna oil to prevent dirt and moisture build-up.

These are all general recommendations, but always check the manufacturer’s specific instructions before using any cleaning or protective products on sauna wood. Remember that every wood is different and has its own specific requirements that must be followed to keep it in the best possible condition.

Frequently asked questions about caring for wood in the sauna

How do you keep your sauna floor in good condition?

The sauna floor is particularly prone to wear and tear and therefore requires special care. Regular cleaning with a gentle cleaner is key. It is also advisable to use mats that can protect the wood from excessive wear and tear.

How to secure the sauna benches?

Sauna benches are exposed to sweat and oils. It is important to clean them regularly using suitable cleaning products. It is also advisable to protect the surface of the benches with special sauna oil to provide an extra layer of protection. Do not sit on the bench with your bare body so that the wood does not absorb sweat and turn yellow. Use a towel or a special mat, which can be made of wood or fabric.

Can I use wood cleaners normally used in the home?

Not always. Some cleaners may be too aggressive for the wood in the sauna. Always check the manufacturer's recommendations before using any cleaner.

How often should I carry out a deep cleaning of the wood in the sauna?

It is recommended to carry out a deep cleaning at least once a year, although this may depend on the intensity of use of the sauna.

How can I remove wood stains from the sauna?

To remove wood stains in the sauna, we recommend using specialised products designed for this purpose.
For example, you can use a sauna care kit from Harvia: this kit contains a cleaner to remove wood stains and oil to protect the surface after cleaning.

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Since 2011 I have had my own business selling sauna building materials, sauna cookers and sauna accessories. I know all about building a quality sauna!