To clean a sauna: let it cool, vacuum or sweep out the dust, wipe the benches and walls with warm water and a mild soap, scrub sweat stains with a baking soda paste, rinse, and leave the door open so it dries completely. Never use bleach, harsh chemicals or a pressure washer on sauna timber. Wipe the benches after every session and give it a full clean every week or two if you use it often.
This guide covers the tools you need, a step-by-step clean, how to get sweat stains out of a cedar sauna, cleaning the heater, stones and accessories, mould, and whether to oil the wood.
Key Takeaways:
- Be gentle: warm water, a mild natural soap and a soft brush are all you need.
- Keep it dry: air the sauna out after every use to stop mould and timber damage.
- Prevent stains: always sit on a towel, and shower before you go in.
Understanding Different Types of Saunas
Cleaning is much the same for every sauna, but it helps to know which kind you have:
- Traditional (Finnish) sauna: 70 to 100°C with low humidity, which rises when you pour water on the stones. The benches take the most sweat.
- Steam room: around 40 to 50°C and close to 100% humidity, usually tiled, so mould is the main thing to watch. See wet vs dry sauna.
- Infrared sauna: cooler and dry, with no stones. Keep water away from the panels and controls.
Why It’s Important to Clean Your Sauna Wood
Sauna wood lives with heat, moisture and sweat. Cleaned regularly, it stays fresh, smells good and lasts for decades. Left alone, sweat soaks in, the timber darkens, and damp spots can grow mould.
Essential Tools and Products for Cleaning Sauna Timber Surfaces
- A mild cleaner: warm water with a little natural soap, or a sauna wood cleaner. In Finland, the classic is mäntysuopa, a pine soap. A weak vinegar and water mix works on light grime.
- A soft brush and cloths: nothing abrasive that scratches the wood.
- Fine sandpaper (150 to 180 grit): for stubborn stains, always sanding along the grain.
Never use bleach, strong disinfectants or a pressure washer. They damage the timber, and chemical residue can give off fumes when the sauna heats up.
Step-by-Step Guide on How to Clean Sauna Wood
Step 1: Sweep and Vacuum the Sauna
Make sure the sauna is cool. Vacuum with a soft brush attachment, working along the grain of the wood, to lift dust and grit from the benches, walls and floor.
Step 2: Wash with a Mild Cleaner
Wipe the benches, backrests and walls with a cloth dipped in warm water and mild soap. Scrub gently with a soft brush where needed. Wipe again with a clean, damp cloth to remove the soap, then leave the door open so the wood air dries. Do not soak the wood.
Step 3: Remove Sweat Stains from Cedar Sauna
How Do You Get Sweat Stains Out of a Cedar Sauna?
- For light stains, wipe with warm water and a little mild soap.
- For darker stains, mix baking soda and water into a paste, spread it on, and scrub gently with a soft brush. Rinse with a clean, damp cloth.
- For stains that will not shift, sand lightly with 150 to 180 grit paper, along the grain.
The best fix is prevention: always sit and lean on a towel.
Step 4: Clean the Vents and High-Touch Areas
- Vents: vacuum the dust out, and wipe the covers with a damp cloth.
- Door handle, glass and controls: wipe them down with a damp cloth and mild soap.
- Floor: wash tiles or duckboards and let them dry fully.
How to Clean Sauna Heater
- Turn it off and let it cool completely. For an electric sauna heater, switch it off at the isolating switch.
- Remove dust: use a soft brush or vacuum on the outside and vents. On a wood heater, clear out the ash regularly.
- Wipe the outside with a barely damp cloth. Keep water away from electrical parts.
- Look for damage: if you see damaged elements, loose wiring or rust, call a licensed electrician or the supplier. Do not repair electrical parts yourself.
How to Clean Sauna Accessories
Cleaning Sauna Stones
Once or twice a year, or more if you use the sauna a lot, take the stones out of the cold heater. Throw away any that are cracked or crumbling, rinse the good ones in water, and let them dry completely before you put them back. Restack them loosely so air can flow between them, and top up with new stones as needed.
Cleaning Pails and Ladles
Wash buckets and ladles in warm water with mild soap, rinse, and let them dry fully so they do not grow mould. Empty the bucket after each session.
Cleaning Other Accessories
Wipe backrests and headrests with a damp cloth and mild soap. Dust thermometers and hygrometers with a soft, dry cloth. Wash towels and sauna hats regularly.
Wood Maintenance: What Is the Best Treatment for Sauna Wood?
Treating Wood for Better Longevity
Inside a sauna, only use oils made for sauna timber. Paraffin oil is the most common choice for benches: it is colourless and odourless, and it helps the wood shrug off sweat and water. Never use varnish, paint or outdoor sealers inside.
Do You Need to Oil the Wood in a Sauna?
No, it is optional. Many saunas are left as bare wood and simply cleaned. Oiling the benches makes sweat stains easier to wipe off, but it can slightly darken the timber. Outside, a barrel or log sauna does need a protective exterior oil or stain to handle the sun and rain.
Our sauna care range includes paraffin oil for the inside and WeatherProof oil for the outside.
Common Sauna Maintenance Questions
How Do You Restore Wood in a Sauna?
Sand the benches lightly with 150 to 180 grit paper to remove stains and grey patches, vacuum off the dust, wipe with a damp cloth, and let it dry. Then oil the benches with paraffin oil if you like.
How Often Should You Clean Your Sauna?
- After every use: wipe the benches and leave the door open to dry it out.
- Every week or two (if you use it several times a week): a full clean of benches, walls and floor.
- Once or twice a year: check and rinse the stones, and sand the benches if needed.
Avoid These Mistakes When Cleaning Your Sauna Wood
- Bleach or harsh disinfectants: they damage the wood, and residue can give off fumes in the heat.
- Pressure washers or hosing: they force water deep into the timber.
- Closing it up wet: always let the sauna dry fully, door open, before you shut it.
How to Handle Mould in Your Sauna
Act quickly. Scrub the spot with a mix of hydrogen peroxide and baking soda (not bleach), wipe it clean and let it dry fully. If mould keeps coming back, the sauna is not drying out between sessions: leave the door open after use, and check the ventilation.
Should You Seal Your Sauna Wood?
Never seal the inside. The wood needs to breathe, and sealers can crack, get hot to touch and give off fumes. Do protect the outside of an outdoor sauna with an exterior oil or stain made for timber.
Tips to Keep Your Sauna Wood Clean for Longer
- Towels and showers: shower before you go in, and always sit on a towel.
- Air it out: leave the door open after each session so the steam escapes.
- Wipe as you go: a quick wipe of the benches with a damp cloth after each session saves a big clean later.
FAQs on Cleaning Saunas
What is the best sauna cleaner?
Warm water with a little mild, natural soap, such as a pine soap, or a cleaner made for sauna wood. Baking soda paste for stains.
How do you clean a cedar sauna?
Vacuum, wipe with warm water and mild soap, treat stains with baking soda paste, rinse with a damp cloth and air dry. Cedar needs no special treatment inside.
Can I paint or stain my sauna interior?
No. Paint, stain and varnish stop the wood from breathing and can give off fumes when heated. Only the outside of the sauna should be stained or sealed.
Can you use regular cleaning products on sauna wood?
Avoid them. Harsh cleaners can damage the timber and leave residue that gives off fumes in the heat.
Is there a difference in cleaning a cedar sauna and a thermowood sauna?
Very little. Both are low-maintenance and clean the same way. Thermowood can be oiled with paraffin oil for extra protection, which slightly darkens it.
Why are towels so important in the sauna?
They stop sweat soaking into the wood, which is the main cause of dark stains on benches. See what to wear in a sauna.
Wrapping Up
A clean sauna is mostly about small habits: a towel, a quick wipe and an open door after every session, and a gentle clean every week or two. Do that, and your sauna wood will look and smell great for years. For oils and care products, see our sauna care range.
