How to Clean a Sauna: Benches, Floors, Walls & Heater

Short answer

Sit on a towel, wipe the benches and let the sauna dry after each session. About once a week, or more often with heavy use, scrub the benches with a soft brush, warm water and a mild cleaner, and wash the floor. Clean only when the heater is off and cool. Never paint, stain or varnish the inside.

A sauna stays fresh with very little work, as long as you do the small things often. Below is a simple cleaning routine based on what sauna and heater makers write in their own manuals, with separate tips for traditional saunas, infrared cabins, outdoor saunas and steam rooms. If your sauna already smells or shows mold, also read how to prevent mold in a sauna and why a sauna smells.

Before you start: heater off and cool

Only clean a sauna when the heater is switched off and has cooled down completely. Clearlight also asks you to unplug its infrared saunas before cleaning. Use mild products: Clearlight recommends non-toxic, no-VOC cleaners, and Harvia’s own heater cleanser should not be used together with chlorinated substances, according to Harvia.

Sauna cleaning schedule

Sauna cleaning schedule based on manufacturer care instructions (checked 21.10.2026)
When	What to do	Source
Every session	Sit or lie on a towel; empty the water bucket; wipe the benches and let the room dry	Harvia KIP manual (towel, bucket)
About weekly (or by use)	Scrub benches with a soft brush and soap and water or a mild disinfectant; wash a waterproof floor with disinfectant	Harvia KIP manual
As needed	Wipe water stains off the heater; scour bucket and ladle when a film forms; remove limescale with water and vinegar or citric acid	Harvia KIP manual, Harvia care tips
Once or twice a year	Treat benches with paraffin oil (optional); re-stack and brush the stones, replace crumbling ones	Harvia care tips
Infrared cabins	Damp cloth inside; lint roller or soft brush on flocked heaters; blow dust out of the vents	Clearlight manual

How to clean sauna benches

Benches get the most sweat, so they need the most care. Harvia’s heater manual says each bather should sit or lie on a towel for hygiene, which also prolongs bench life. A towel big enough for the bench does most of the work for you.

For a proper wash, Harvia describes these steps:

Wash the benches with warm water and a suitable cleaning solution, using a soft brush.
Always brush along the grain of the wood.
Rinse a few times to remove the detergent, then rinse once with cold water.
Dry the sauna carefully by heating it for at least 30 minutes.
Once the benches are clean and dry, you can treat them with paraffin oil. Test it in a hidden spot first, for example under a bench.

Perspiration darkens wood over time. Harvia, Clearlight and Almost Heaven all suggest lightly sanding stained areas with fine-grit sandpaper once the wood is dry. Learn more about wood types in the best wood for a sauna.

How to clean sauna walls and ceiling

Walls and ceilings get less sweat than benches but collect dust. Almost Heaven recommends vacuuming or brushing out the sauna periodically and removing dirt or stains with a solution of baking soda and water, scrubbing lightly and then rinsing. For its barrel saunas, it also mentions pressure washing the interior with a low-pressure, wide-pattern nozzle. Check your own manual before using water that freely on other sauna types.

How to clean the sauna floor

Harvia recommends washing a waterproof floor with a disinfectant about once a week or as often as needed, and hosing off removable flooring. It strongly recommends an easy-to-clean floor such as concrete, ceramic tile or a poured floor. Harvia advises against carpet, which can become a breeding ground for bacteria in the moist conditions of a sauna and can spread foot infections such as athlete’s foot, and for the same reasons against wooden duckboards. More on floors and water in do saunas need a drain.

How to clean the heater, stones and bucket

Wait until the heater is cold. Harvia’s manual says a properly installed electric heater needs no special maintenance; wipe off water stains with a damp cloth now and then. For visible limescale, Harvia recommends a mix of water and vinegar or citric acid powder.

Stones: Harvia recommends re-stacking the stones every year and using that moment to clean them with warm water and a soft brush. If stones crumble or look yellowed, replace them. See when to replace sauna rocks and which rocks to use.
Water for the stones: Use only clean tap water. Harvia warns that pool, spa or well water can produce chlorine gas or damage the heating elements.
Bucket and ladle: Harvia says to use clean water, dump it out after every use, and scour the bucket and dipper when a film builds up.

How to clean an infrared sauna

Clearlight says its infrared saunas provide dry heat and need minimal cleaning. Its care steps:

Unplug the sauna and let it cool completely before cleaning.
Wipe the inside with a damp cloth.
For a thorough clean, use a non-toxic, no-VOC sauna cleaner, a few drops of essential oil in water, or 1 tablespoon of baking soda in a gallon of water.
Use pure or distilled water to reduce mineral buildup.
Clean flocked surfaces on full-spectrum heaters with a lint roller or a soft brush.
Blow dust out of the vents with canned air, a vacuum with a soft brush or a hair dryer on the cool setting.
Care for the outside with a non-toxic, no-VOC furniture polish.

How to care for an outdoor sauna

Outdoor saunas can collect more dirt from the garden, so you may need to sweep and vacuum more often. Almost Heaven ships its barrel saunas with untreated wood and recommends treating the outside only with an exterior-grade stain or sealant, ideally with a UV inhibitor. It says never to use varnish or paint on the exterior and never to treat the interior unless the product is approved for sauna use. Almost Heaven also suggests checking the band tension and fading every few months, especially in the first months.

How to clean a steam room

Steam rooms are tiled, wet spaces and follow different rules from wooden saunas. For the controls and steam head, MrSteam recommends only mild soap and water on a soft cloth and no abrasive cleansers. For tiles, grout and seats, follow the instructions from your installer or tile manufacturer. We do not give a general recipe here, because surfaces differ.

What not to use in a sauna

Paint, varnish, stains or sealers inside: Harvia does not recommend stains or sealers because toxic vapors may appear when heated. For commercial saunas it allows two coats of Harvia sauna sealer on the benches.
Harsh or solvent-based cleaners: Clearlight recommends non-toxic, no-VOC products; Harvia’s heater cleanser must not be mixed with chlorinated substances.
Pool, spa or well water on the stones: Harvia warns about chlorine gas and heater damage.
Carpet or wooden duckboards on the floor: Harvia advises against both for hygiene reasons.

Keep your sauna cleaner for longer

The easiest cleaning is the one you do not have to do. Finnish sauna guides such as InfoFinland ask you to shower well before the sauna and to cover the bench with a sauna bench towel before sitting down. After your session, leave the door open so the room can dry out. In a gym, see how sanitary gym saunas are. Cleaning a portable unit instead? Read how to clean a sauna blanket.

Frequently asked questions

How often should you clean a sauna?

Wipe the benches and let the room dry after every session. Harvia’s heater manual suggests scrubbing the benches and washing the floor about once a week in commercial saunas, or depending on how much the sauna is used. In a home sauna, let your own use decide.

What is the best way to clean sauna benches?

Harvia recommends warm water, a suitable sauna cleaner and a soft brush, brushing along the grain. Rinse a few times to remove the detergent, finish with cold water, and dry the sauna by heating it for at least 30 minutes. Sand dark stains lightly once the wood is dry.

Can you use baking soda to clean a sauna?

Yes. Clearlight suggests 1 tablespoon of baking soda in a gallon of water for a deeper clean of its infrared saunas, and Almost Heaven recommends a baking soda and water solution for stains on its barrel saunas, followed by a rinse. For a lighter clean, Clearlight mentions a few drops of essential oil in water.

Should you seal or varnish the inside of a sauna?

No. Harvia does not recommend stains or sealers inside the sauna because toxic vapors may appear when they are heated, and Almost Heaven says never to treat the interior unless the product is approved for sauna use. Harvia sells a paraffin oil for benches as a sauna-specific option.

How do you clean sauna stones and the heater?

Wait until the heater is off and cool. Harvia recommends wiping water stains off the heater with a damp cloth and removing limescale with water and vinegar or citric acid. Re-stack the stones once a year, brush off dust with warm water, and replace stones that crumble.

How do you clean an infrared sauna?

Clearlight says infrared saunas need minimal cleaning. Unplug the sauna and let it cool, wipe the inside with a damp cloth, and use a non-toxic, no-VOC cleaner for a thorough clean. Clean flocked heater surfaces with a lint roller or soft brush, and blow dust out of the vents.

Sources

This guide is based on the linked care instructions from Harvia, Clearlight, Almost Heaven and MrSteam, checked on October 21, 2026. We did not test cleaning products ourselves. Always follow the manual for your own sauna and heater, because wood types, finishes and heaters differ.