What makes cedar different
Cedar is a popular sauna wood because it holds up well to heat and humidity and has a pleasant natural scent. It is also untreated wood, which means it absorbs liquids, sweat, and cleaning products. The general rule from sauna suppliers is to clean gently, use as little water as you can, and let the wood dry well afterward. Soaking the wood or hosing it down tends to encourage bacteria and mold and can damage the fibers.
Safety notes
- Turn off the heater and let the sauna cool fully before cleaning. Surfaces, rocks, and heater parts stay hot for a long time.
- Check your manual or ask the sauna maker, since care advice varies between manufacturers.
- Avoid bleach and harsh detergents. They can damage the wood, leave residues that heat up with the next session, and give off fumes in a small hot room.
- Never mix cleaning products. Bleach should never be combined with vinegar or ammonia, and hydrogen peroxide should never be mixed with vinegar in the same container. Use only one product at a time and rinse between products.
- Ventilate well, keep the door open, and wear gloves.
- Keep children and pets out until the sauna is dry and aired out, and keep cleaners out of reach.
- Keep water and cleaners off the heater and any electrical parts.
What you need
- Vacuum with a soft brush attachment, or a soft broom
- Two buckets, one for cleaning solution and one for rinse water
- Warm water (not hot)
- Mild soap, such as a diluted gentle liquid soap, a pH-neutral wood soap, or a cleaner made for saunas
- Soft cloths or sponges and a soft brush
- Fine-grit sandpaper (around 120 to 220 grit) for stubborn marks
- Dry towels
Step-by-step deep clean
- Cool and open up. Turn the heater off, let it cool, and open the door and vents.
- Empty the sauna. Take out towels, buckets, ladles, backrests, and removable floor slats or duckboards.
- Dry-clean first. Vacuum or sweep hair, dust, and grit from benches, corners, and the floor.
- Wash gently. Dip a cloth in the soapy water and wring it out so it is damp, not dripping. Wipe benches, backrests, and walls, going with the grain of the wood.
- Rinse. Wipe again with a cloth dampened with clean water to remove soap.
- Dry. Wipe up any water with a dry towel, prop the door open, and let the sauna air out. Some suppliers suggest running the heater for a while with vents open to finish drying. Check the manual for how long.
Routine care after sessions
- Sit on a clean towel so sweat does not soak into the wood.
- Wipe the benches with a slightly damp cloth after use, then dry them.
- Leave the door ajar so the room can dry.
- Take out towels and accessories rather than leaving them in the damp room.
Stains, dark spots and odors
Sweat can darken the wood over time. For light marks, a damp cloth with a little mild soap may be enough. For stubborn spots, sand lightly along the grain with fine-grit paper, then wipe off dust with a barely damp cloth. Sanding also exposes fresh wood and can bring back the cedar scent. Odors usually come from moisture and sweat, so thorough drying and airing out are the best fixes.
Mold or mildew spots
A musty smell, black spots, or fuzzy growth suggests moisture is not escaping. Isolate small spots and clean them with a mild soap solution, then dry. Some sauna guides suggest a diluted hydrogen peroxide or vinegar solution for spot treatment, but never combine the two, and test in a hidden area first. Heavy or widespread mold may mean ventilation problems or deeper damage, and a sauna professional can advise on repair.
Floor, duckboards and accessories
Remove duckboards and wash them separately, then dry completely. If your sauna has a floor drain, it is meant for spills, not for flooding the walls. Wash buckets and ladles with mild soap and let them air dry.
Heater, rocks and electrical parts
Do not spray liquids on or around the heater. Rocks can be rearranged or replaced as your manual describes, but only when the heater is off and cold.
What to avoid
- Hosing down or soaking the wood
- Bleach, ammonia, or heavy degreasers
- Strongly scented products that linger when heated
- Pressure washers
- Wire brushes
- Varnish or sealants on benches and interior walls, unless the sauna maker says they are meant for it
If you want to treat the wood, ask your sauna supplier about products made for sauna interiors, such as paraffin-based oils.
How often to clean
A quick wipe after use, a weekly or monthly light clean depending on how often the sauna is used, and a thorough deep clean every few months is a reasonable pattern. Follow your manual if it says otherwise.
Infrared saunas
Infrared saunas often have different heating panels and finishes, so the manufacturer’s instructions matter more. In general, wipe wood surfaces with a lightly damp cloth, avoid soaking, and keep moisture away from the heaters.