Treating the wood in your sauna with oil is optional, and not something everyone will opt to do. If you maintain the wood by scrubbing it down with a brush after every use and use some light sandpaper to scuff off any rough spots, your sauna wood should last for years. However, not all sauna wood is the same kind of wood and some wood responds very well to being oiled. Here we will cover how to treat a sauna with wood oil.

Types of Wood Used in Saunas

Saunas are made of many kinds of wood, some of the most popular are:

  • Alder- Alder is an extremely popular type of wood used in sauna construction. It has a slight red tint and is known for being fairly water repellent, which is a good quality to have for sauna wood. The most common types of alder are common alder or black. It grows primarily in Africa, Asia, and Europe.
  • Cedar- Cedar is an excellent wood for the benches in any sauna, and you have sat on a cedar bench if you have been to a few saunas in your life. It is used because it does not get too hot or secrete any type of resin when heated. It has a wonderful smell and a very vivid red color that really sets it apart from other woods.
  • Pine- Pine is a pretty wood that has many species. The most common species of pine used in saunas is radiata pine. This wood is thermally treated to achieve the darker color you will see. Without treatment is a lighter color. It has no exposed knots and much like cedar, it does not excrete resin or get too hot to the touch.
  • Spruce- Spruce has some different species as well, but the one you may see the most in saunas is the European spruce. It has an exceptionally light color. This wood is not typically used on benches or interior doors, but it deserves a mention here because it is quite common in the construction of saunas, both stand-alone and interior.
  • Ash- This is an expensive wood that naturally is not the dark color you normally see in saunas. Companies that make these saunas have a system they use to temperature treat the wood, so it becomes a dark brown color. It is a hardwood that looks great on sauna floors and ceilings.
  • Poplar- This wood is great for sauna benches and interior walls. It grows commonly in the United States and Canada and belongs to the same family as Aspen trees do. Since the wood does not have any exposed knots, nor does it splinter, it is used for surfaces that people will touch. It is a hearty wood that looks great in saunas and any other structure.

When to Oil Sauna Wood

There are differing opinions on this topic, some people are against oiling while others love it. The fact of the matter is that if you take care of your wood and keep it clean, you probably will not have to oil it very often.

If you notice your benches and backrests starting to look a little dried out or discolored and dirty, it may be time to consider oiling them. The benches are the only surface beside any doors you may touch that will need oiling. The idea behind oiling the wood is to keep it healthy and stop it from drying out. If you allow your benches to become dry, they may start to splinter which can mean you have to replace the wood, which is much too costly.

It is always best to err on the side of caution and oil your benches at the first sign they may need it. You do not even have to wait that long, as many people just decide to oil the wood as a preventative measure.

Preparing the Wood for Oil

Preparation is the key to any successful project. If you follow these steps before you apply the oil, the entire project will go very smoothly!

Clean the Wood

If you decide you are going to go for it, the first step is to make sure that before you put anything on the surface of your benches or doors to be sure they are clean and dry. It is OK to use a low-pressure wash to remove excess dirt or oils from the surfaces, but not too much pressure as you can easily rip and tear the wood. Once it is visibly clean, you can go one step further.

Sanding the Surfaces

Using some low grit sandpaper, you can gently scuff the surface of any wood you plan to treat with oil. Make sure you use a mask when you do this step because wood dust is harmful to your lungs. Once you have sanded all the surfaces you will notice some dust sitting on the benches and doors.

Final Dusting

One of the best ways to remove this dust is to get a damp rag with a little water on it and wipe them down thoroughly. Alternatively, you can use some cheesecloth to achieve the same goal. Just follow the grain of the wood and apply gentle pressure on the cloth, turning it over to a clean side until you have touched all the surfaces.

Leave to Dry

Once the surfaces have been cleaned and gently sanded, and finally dusted, make sure you leave them to dry. They need to be 100% dry before you put any oil on the surface. You can leave the door open with a fan inside pointing outward to blow out any dust or moisture and prevent new dust from coming in.

How to Treat a Sauna with Wood Oil – What Kind of Oil to Use?

There are more than a few different kinds of oil you can purchase that are recommended for wood surfaces. Different kinds of wood call for different oils. In the case of treating wood inside a sauna, you need to consider the environment the wood is being exposed to before reaching for some random wood oil to protect it.

Because of the high heat and moisture environment inside a sauna, it is not recommended to use anything that will emit fumes over time or negatively interact with human skin. It could be dangerous to be in a hot sauna for 20 minutes or more breathing a toxic chemical you cannot smell!

For this reason, it is recommended to only use paraffin oil on surfaces inside a sauna.

What is Paraffin Oil?

This oil is derived from petroleum much like motor oil is. It is also called kerosene in some parts of the world. It is a colorless oil that will not dissolve in water which has no real smell or taste.

It is generally considered safe to use on sauna wood because it will not cause fumes that could make you sick. Many of the other wood oils have too many chemical compounds and fumes that would not be healthy for you to breathe in for an extended amount of time.

What Kind of Paraffin Oil Should be Used?

There are a variety of oils available that claim to be perfect for sauna benches. You can make your own decision on which one is best for your application, just keep in mind you do not want any fumes or unnecessary aromas. The oil you choose should be safe and non-toxic, without any additional ingredients. The closer you can get to pure paraffin oil the better for your sauna wood.

How to Apply Oil to Sauna Wood

Warning: If you have not oiled your wood before, this will change your wood to a darker color. Do not proceed if you are afraid of darkening the wood!

If you have followed the preparation steps, you should have clean, dry, smooth, dust-free surfaces to work with. If your surfaces are ready, here is the best way to apply the oil.

You will need:

  • Latex gloves
  • Some clean rags
  • Fresh paintbrush
  • A small metal or plastic bucket
  • Paraffin oil

First, you will put on your gloves to protect your hands from getting any oil on them. Next, take a small amount of the oil and pour it into your bucket.

Take the paintbrush and dip it in the oil, tapping off any excess oil on the inside of the bucket. Once there is no oil dripping from the brush, start brushing with the grain on your wood. Make sure you are getting every surface and pushing the oil deep into the wood.

Continue brushing all the surfaces and using the rags as you go to gently get any drips or messes you may make along the way. Try to get a system going so you can remember where you have brushed and where you have not. I like to go clockwise.

Once you are certain you have got all the bench and door surfaces that need to be oiled, go back over your work and double-check for spots you could have missed. It is easy to miss spots with oil. If you can confidently say it is all oiled, you are done!

Just make sure you give it ample time to dry, maybe leave the door open and fan blowing fresh air in for a while.