Sauna maintenance

A sauna asks very little upkeep — but the little it asks, it asks firmly. Clean the wood gently, dry it out religiously, mind the stones, and it will outlast almost anything else you own.

Last verified July 26, 2026 · Ice & Cedar editorial

The good news is that a sauna is one of the lowest-maintenance things in a home recovery setup. The catch is that the little maintenance it needs is specific: the products and instincts you use to clean the rest of your house are mostly wrong here, and the single most important habit — drying it out — is the one people skip.

Get three things right and a sauna lasts for years: clean the wood gently, dry it thoroughly after every use, and look after the stones and heater. Here is each, plus how to fix a sauna that has already started to smell. As always, the manufacturer’s instructions win over any general tip.

1. Clean the wood — gently, and never seal it

Wipe the benches, backrests and floor with warm water and a soft brush, or a mild sauna-safe cleaner, and rinse lightly rather than soaking. Avoid harsh chemicals, bleach and strong scents— the wood is porous, and the heat will drive residues right back out into the air you breathe. For stains or discolouration on bare wood, light sanding is the traditional fix, not a chemical one.

And do not seal or varnish the interior. The bare wood inside a sauna is meant to breathe and absorb moisture; sealing it traps that moisture, can make surfaces too hot to touch, and can release fumes when heated. Leave the inside natural and manage it by cleaning and drying. Only the exterior of an outdoor sauna may be treated, per the maker’s guidance, to handle the weather.

2. Dry it out — this is the whole game

Almost every sauna problem — smell, mold, premature wear — traces to moisture that never got to leave. So the most important habit is the simplest: after each session, open the door and vents and let the sauna air out and dry completely before you close it up. Wipe standing sweat and water off the benches and floor so it is not sitting there overnight.

Make sure the room’s ventilation is working the way the heater manufacturer intends, too — airflow is part of both heating and drying. A sauna that dries out after every use essentially never smells; a sauna sealed up damp will, and then you are deep-cleaning instead of just airing out. Drying is five minutes of habit that prevents the one maintenance job nobody enjoys.

3. Mind the stones and the heater

Stonesbreak down over time from repeated heating and cooling, and a well-used traditional sauna typically wants them checked around once a year. Crumbling stones pack together and block airflow through the heater, which hurts performance. Take them out periodically, discard any cracked or crumbling ones, and re-stack the rest loosely so air moves between them — using only proper heater-rated stones, because the wrong rock can crack violently when heated.

The heaterneeds less, but not nothing. Keep an electric heater clear of debris and its stones correctly loaded, and leave anything electrical to a professional. A wood-burning heater needs its chimney and flue swept periodically to stay safe and drawing well, plus ash removal. If a heater seems to be underperforming, it is more often a room or sizing problem than a fault — the not-getting-hot-enough checklist works through the causes in order.

Frequently asked questions

How do you clean a sauna?

Gently, and without the products you would use elsewhere in the house. Wipe the benches and backrests with a mild, sauna-safe cleaner or just warm water and a soft brush, and rinse lightly rather than soaking the wood. Let it dry fully afterward. Avoid harsh chemical cleaners, bleach and anything strongly scented - the wood is porous, the heat will drive residues back out into the air you breathe, and strong products can damage the surface. For stubborn stains or discolouration on bare wood, light sanding is the traditional fix rather than a chemical one. The goal is clean and dry, not sterile.

Should I seal or varnish the inside of my sauna?

No - not the interior wood you sit on or touch. The bare, untreated wood inside a sauna is meant to breathe and absorb moisture, and sealing or varnishing it traps moisture, can make surfaces uncomfortably hot to touch, and can release fumes when heated. Leave the interior wood bare and manage it by cleaning and drying instead. Exterior surfaces of an outdoor sauna are a different matter and may be treated per the manufacturer's guidance to handle the weather, but the inside stays natural. When in doubt, follow the maker's instructions over any general tip.

How do I stop my sauna from smelling or growing mold?

Dryness is the whole answer. Mold and odour come from moisture that never gets a chance to leave, so the fix is ventilation and drying: after a session, open the door and any vents and let the sauna air out and dry completely rather than sealing it up damp. Wipe up sweat and standing water from benches and floor, and make sure the room's ventilation is working as the heater manufacturer intends. A sauna that is dried out after each use rarely develops a smell; one that is closed up wet will. If a smell has already set in, deep-clean the bare wood, sand stubborn spots, and above all fix the drying routine.

How often should I replace sauna stones?

When they start to break down, which for a well-used traditional sauna is typically every year or so, though it varies with use and stone quality. Sauna stones crack and crumble over time from repeated heating and cooling, and broken-down stones pack together, block airflow through the heater and hurt performance. Periodically take the stones out, discard any that are cracked or crumbling, and re-stack the rest loosely so air can move between them, adding new heater-rated stones as needed. Use only proper heater stones - the wrong rock can crack violently or be unsafe when heated.

What maintenance does the heater need?

Less than the wood, but do not ignore it. For an electric heater, keep it free of debris, check that the stones are correctly loaded and not blocking elements, and have any electrical concern looked at by a professional rather than poking around a 240V appliance yourself. For a wood-burning heater, the chimney and flue need periodic cleaning to stay safe and drawing well, plus ash removal and the usual stove care. If a heater is underperforming, that is often a room or sizing issue rather than the heater itself - our 'not getting hot enough' checklist walks through the causes in order.

Do infrared saunas and sauna blankets need the same maintenance?

Less, because they have no stones and no steam. An infrared cabin mainly needs the bench and interior wood wiped down and kept dry, the same gentle cleaning and no sealing as any sauna, but there are no stones to replace and no chimney to sweep. A sauna blanket is different again - it is a heated wrap, so follow the manufacturer's cleaning instructions for the interior surface, wipe it down after use, and store it dry and unfolded rather than balled up damp. In all cases the principle is the same: clean gently, dry thoroughly, and follow the maker's guidance.

Sources

Ice & Cedar sauna accessories and heater guides — The stone-care and heater points here draw on the accessories and heater guidance published elsewhere on this site. The wood-care and drying guidance is general sauna best practice; on any specific product, the manufacturer's own care instructions take precedence over anything here. (accessed 2026-07-26)