How to clean and maintain a sauna

A clean sauna is more pleasant to use, more hygienic, and longer-lasting, and keeping one clean is far less work than people expect. The trick is small, regular habits rather than occasional deep scrubs. This guide covers routine care, a simple cleaning schedule, how to handle stains and mold, and the few things you should never do inside a sauna.

Why cleaning a sauna matters

Sweat, body oils, and humidity are part of every session, and over time they can leave marks on the wood, encourage mildew, and create a stale smell. Staying ahead of that does three things:

• Keeps it hygienic. Benches and floors are where sweat collects, so regular cleaning keeps the space fresh for everyone who uses it.
• Protects the wood. Untreated sauna wood lasts for years when it can dry out properly, but trapped moisture shortens its life and leads to staining.
• Prevents odor and mold. A dry, well-aired sauna simply does not give mildew a chance to take hold.

None of this requires special products or much time. A clean sauna is mostly the result of letting it dry out and giving it a quick wipe, done consistently.

A simple cleaning schedule

The easiest way to stay on top of maintenance is to spread small tasks across a routine. Here is a sensible baseline you can adapt to how often you use your sauna.

Treat this as a guide, not a rulebook. A home sauna used twice a week needs less than a busy shared one, but the rhythm of light-and-frequent care holds either way.

Routine after-use care

What you do right after a session matters more than any deep clean, because moisture is the real enemy of a sauna.

1. Ventilate. Leave the door open, and crack a vent or window if you have one, so warm, damp air can escape and the room can dry out fully.
2. Wipe the benches. A quick pass with a clean, damp cloth removes the worst of the sweat before it soaks in.
3. Dry standing water. Mop or towel up any puddles on the floor or benches so nothing sits and seeps into the wood.

The single best habit is to sit on a towel during every session, so sweat lands on cloth rather than soaking into the bench. It is the easiest way to keep the wood clean, and our guide on what to wear in a sauna covers towel etiquette in more detail.

Cleaning the benches and floor

Benches and the floor are where sweat and grime concentrate, so they deserve the most attention during your weekly and monthly cleans.

For the benches, use warm water with a little mild dish soap or diluted white vinegar and a soft cloth or brush. Work along the grain, then wipe with clean water and let everything dry. Avoid soaking the wood; a damp cloth is enough.

For the floor, sweep or vacuum first, then wipe or mop with the same mild solution. If your sauna has duckboards (the slatted wooden mats some saunas use), lift them out so you can clean underneath, where water and debris collect. Sauna floor drains should be flushed and cleared monthly so they do not clog or start to smell.

Cleaning the wood and removing stains

Sauna wood is left untreated on purpose so it can breathe, which means it cleans up simply but also stains more readily. Stick to gentle methods:

• Everyday marks lift with warm water and mild soap or diluted vinegar on a soft brush.
• Stubborn stains can be eased out by lightly sanding along the grain with fine-grit sandpaper, then wiping away the dust. Go gently and stop as soon as the mark fades.
• Strong smells usually mean the wood has not been drying out. Air the room thoroughly rather than masking the odor with scented products.

Crucially, do not seal, varnish, or oil the interior wood after cleaning. Those finishes trap heat against your skin, can release fumes, and stop the wood from doing its job. The bare surface is meant to stay bare.

Preventing mold and mildew

This is the part that protects your sauna most, and it comes down to one principle: keep it dry and well-ventilated.

• Air it out after every use by leaving the door open until the interior is fully dry.
• Mop up moisture rather than letting water sit on wood.
• Fix humidity at the source. If the room around the sauna stays damp, the sauna will struggle to dry, so address ventilation or a humidity problem in the wider space.

Mold is especially worth watching in lower-level installations, where airflow is limited and damp lingers. If yours lives downstairs, our basement sauna guide covers ventilation and moisture control in that setting. If you do spot a small patch of mildew, wipe it with diluted vinegar, dry the area completely, and improve the airflow so it does not return.

Heater and stones (traditional saunas)

A traditional rock heater needs occasional attention, always when it is completely cool.

• Wipe the heater exterior with a dry or barely damp cloth to clear dust and stray debris. Keep water off the elements.
• Check the stones once or twice a year. Over time they crumble, pack down, and restrict airflow, so rinse them, restack them loosely, and replace any that have cracked or rounded off.

Worn stones make the heater work harder and dull the steam, so this small check pays off. Our sauna heater guide goes deeper on stone care and replacement.

Infrared saunas

Infrared saunas are simpler to maintain because they run cooler and drier, with no steam or stones. The main rules are about keeping things dry:

• Wipe the interior surfaces with a soft, just-damp cloth after use.
• Keep the panels dry. The emitters are electrical, so never splash or pour water inside as you would in a traditional sauna.
• Air it out briefly so any sweat on the benches dries.

Because there is no humidity cycle, an infrared cabin rarely develops mold, but the towel habit and a quick wipe still keep it fresh.

Outdoor and barrel saunas

An outdoor or barrel sauna needs everything above, plus care for the exterior that faces the weather:

• Protect the outside. The exterior wood may need periodic sealing or UV treatment to stand up to sun and rain. Follow the manufacturer’s guidance, and remember this applies only to the outside, never the interior.
• Clear debris. Sweep leaves, needles, and dirt off the roof and away from the base so moisture does not collect against the wood.
• Mind the seasons. Before winter, check seals and drainage, and clear snow from the roof and around the door so meltwater can run off.

What to avoid

A few common mistakes do more harm than the dirt they are meant to remove:

• Harsh chemicals and bleach inside the cabin. They are rough on bare wood and leave fumes in an enclosed space.
• Pressure washing the interior. It forces water deep into the wood and warps it.
• Sealing or varnishing interior wood. It traps heat and ruins the surface.
• Strongly scented cleaners. The smell bakes back out during heat-up.
• Leaving it damp. Skipping the airing-out step is the fastest route to mildew.

When in doubt, do less and follow the care instructions that came with your sauna; the maker knows the specific wood and finish you have.

The bottom line

Cleaning a sauna is mostly about good habits: sit on a towel, wipe the benches after each use, and let the cabin dry out fully every time. Add a weekly wipe-down, a monthly scrub of benches and drains, and a yearly deep clean with a heater check, and the wood will stay sound for years. Stick to mild soap, water, or diluted vinegar, keep harsh chemicals and sealants out of the interior, and you protect both the experience and your investment. For a sense of what well-built, easy-to-maintain options look like, see our roundup of the best home saunas, and our sauna cost guide covers the long-term value good upkeep preserves.