A well-built sauna is one of the lowest-maintenance things you’ll ever own. The wood is chosen specifically to handle heat and moisture. The heater is designed to run hot for 5-10 years. There are no filters to swap, no chemicals to balance, no skimmer baskets to empty.
That said, “low maintenance” isn’t “no maintenance.” Skip the basics for a few years and you end up with a sauna that smells off, develops dark sweat marks on the benches, or runs less efficiently than it should. None of it is hard to prevent. It just needs a routine.
This guide walks through how to clean and care for the three main sauna types we sell: traditional electric, wood-fired, and infrared. The fundamentals overlap, but the heater is what’s different, and that’s where most people get the care wrong.
The three habits that matter most
Before any of the type-specific stuff, three habits cover 80% of sauna care:
- Crack the door open after each session and let the room dry out. Ten to fifteen minutes is enough. The heater can stay on for the first few minutes; residual heat plus airflow does the work. This is the single biggest thing you can do to prevent mold and odors.
- Sit on a towel and shower before you go in. Most “sauna smell” is sweat soaked into the bench wood. A bath towel under you and a quick rinse beforehand prevents 90% of it.
- Lift duckboards and hang towels outside. If you have ritilä (slatted floor mats), pull them up after the session so air reaches the floorboards underneath. Don’t leave wet towels in the room.
Do those three things and the rest of this guide is mostly checklist work that takes a few minutes a week.
The maintenance schedule (all sauna types)
Here’s the full routine. Frequencies assume a residential sauna used 3-5 times a week. Use less than that and you can stretch most intervals.
| When | What |
|---|---|
| After each use | Crack door, run heater 10-15 min to dry, lift duckboards, hang towels outside |
| Weekly | Wipe benches and backrests with a damp cloth. Sweep or vacuum the floor |
| Monthly | Mop floor with warm water. Spot-clean sweat marks while they’re fresh. Check vents are unobstructed |
| Annually | Deep clean benches, walls, floor with a sauna-safe wood cleaner. Inspect heater. Restack rocks (traditional) or check panels (infrared). Have a pro inspect electrical or chimney |
| Every 1-3 years | Replace cracked or crumbling heater rocks. Lightly sand benches if you want to refresh the wood color |
Sweat marks are the one thing worth catching early. Fresh ones come out with a damp cloth in seconds. After a few weeks they oxidize into the wood and you’ll need fine sandpaper to fully remove them.
How to clean a traditional electric sauna
A traditional electric sauna runs a 240V heater with rocks on top, and you ladle water onto the rocks for löyly (the soft, heavy steam that defines the sauna experience). Heat and humidity inside the room are both high, so airflow and wood care matter more than in any other type.
Daily and weekly
After each session, leave the door cracked and the heater on for 10-15 minutes to dry the room. Wipe benches once a week with a damp microfiber cloth. If a session was particularly heavy on water, mop the floor afterward.
Annual deep clean
Once a year, take everything out (duckboards, headrests, any removable backrests) and wash them outdoors with mild soap and warm water. Wash benches, walls, and the floor inside the room with a sauna-safe wood cleaner (we sell a few options on shop.saunasupplyco.com) and a soft-bristle brush. Rinse with clean water and a damp cloth. Let everything dry fully before reassembling.
The heater and rocks
Sauna rocks crack and crumble over time from thermal cycling. Once a year, pull all the rocks out, vacuum or wipe the heater interior, and check each rock. Toss any that are cracked, crumbling, or noticeably smaller than they were. Plan on a full rock replacement every 1-3 years if you ladle water frequently.
When you restack:
- Cover every heating element. No element should be exposed to open air.
- Stack loosely with air gaps. You should be able to slide a finger between rocks. Tight packing chokes airflow and trips the high-limit shutoff.
- Big rocks low and around the outside of the elements; smaller rocks on top.
- Stay within the marked rock area on the heater.
We have a full step-by-step guide here if you want to see it done.
Have an electrician inspect once a year
Sauna heaters draw 30-60 amps and run hard. A licensed electrician should check the contactor, wiring connections, and the high-limit switch every 12 months or so. It takes 15 minutes and prevents the kind of failure that takes the heater out completely.
How to clean a wood-fired sauna
Wood-fired saunas have one big advantage on the cleaning side: the stove cools slowly and pulls air through the room as it does, drying everything out for you. The trade-off is that you have a chimney and a firebox to deal with, and ash to manage.
Daily and weekly
After each fire, scoop the ash into a metal container (never plastic, since embers can stay hot for 24 hours) and store it outside, away from the building. Wipe down benches weekly. Sweep around the stove and under the benches.
The chimney
Have your chimney swept at least once a year. If you burn frequently or use lower-quality wood, twice a year is safer. Creosote builds up faster than people expect, and a chimney fire in a wood-fired sauna is the kind of thing you only need to deal with once.
You can sweep it yourself with a chimney brush kit, but the first time, we’d recommend hiring a CSIA-certified chimney sweep. They’ll spot cracks, baffle gaps, and obstructions that are easy to miss.
Stove care
Every six months, look the stove over for rust, warping, or cracks in the firebox. Pull the rocks (if your stove takes them) once a year and replace any that have cracked. Vacuum out the firebox after a full cool-down.
Burn the right wood
Use kiln-dried hardwood: birch, alder, oak, or maple. Avoid:
- Softwoods like pine and spruce (they spit and produce more creosote)
- Painted, treated, or pressure-treated lumber (toxic when burned)
- Wood that’s been sitting wet (smolders, deposits creosote fast)
Smaller, hotter fires are better than long, smoldering ones. They burn cleaner and put less buildup in the chimney.
How to clean an infrared sauna
Infrared saunas heat your body directly with infrared panels instead of heating the air through rocks and steam. The room runs cooler (around 120-140°F vs. 175-195°F for traditional), there’s no water poured anywhere, and humidity stays low. That changes the cleaning routine significantly.
Daily and weekly
After each session, wipe down benches, backrests, and the inside of the door with a clean dry towel to absorb sweat. Once a week, do a damp wipe with a 1:1 mix of distilled white vinegar and water. Vinegar disinfects, doesn’t damage the wood, and doesn’t off-gas anything harmful when the sauna heats back up.
For tougher residue, mix one tablespoon of baking soda with a gallon of warm water and use a soft-bristle brush. Always wring cloths out well. Excess water in the wood is what causes warping.
The infrared panels
This is where infrared diverges from traditional sauna cleaning, and where most owners get it wrong:
- Never spray any liquid directly on a heater panel. Cleaners, oils, and water can all damage the panel surface and shorten its life.
- Dust the panels with a barely damp microfiber cloth. Wipe in one direction, then dry with a clean towel immediately.
- Use a lint roller or a can of compressed air on the heater guards. Dust collects on the protective grills and can affect heat output if it builds up.
- Don’t apply oil, polish, or wax anywhere near the panels. Even on the wood next to them.
If a panel ever stops heating evenly or you see discoloration on the surface, stop using it and call us before you try to clean it further.
Annual check
Once a year, run through the electrical: check that the cord and outlet are clean and firmly seated, that none of the panel connections look discolored, and that the controller is responsive. Most home infrared saunas plug into a standard 120V or 240V outlet, so the work is straightforward.
Wood care fundamentals (all sauna types)
The wood inside a sauna is the part that gets all the attention from new owners, and the part where most online advice goes sideways. Here’s what actually matters.
Never paint, stain, or varnish the interior
The wood needs to breathe. Heat and moisture have to move through it for the room to feel right and for the wood to last. Sealing it traps moisture, prevents proper aging, and produces toxic fumes when the room heats up. This applies to every wood we use: cedar, hemlock, spruce, thermowood, basswood, aspen.
The exception is the door handle and exterior wood. Those can take a wood sealant if you want one, since they’re outside the heat zone.
About sauna oils and waxes
You’ll see paraffin oil and bench-treatment products recommended widely. They’re optional. We don’t push them on customers because:
- Cedar and hemlock don’t really need them. Both species handle heat and moisture without help.
- Some treatments can darken the wood unpredictably or change how it absorbs sweat.
- A fresh sand once every few years does more for the look of the benches than any oil.
If you want to use a bench treatment, stick to products specifically labeled for sauna interiors. Don’t substitute furniture polish, mineral oil, or anything from the household cleaning aisle.
Wood color changes are normal
Your sauna wood will darken over time. That patina is heat and use working on the wood the way they’re supposed to. It’s not damage and it’s not a sign you’re doing something wrong. If you want the original lighter color back, a light pass with 150-180 grit sandpaper across the benches every few years brings it most of the way home and releases the cedar aroma at the same time.
What to use, what to avoid
| Use | Avoid |
|---|---|
| Soft microfiber cloths | Pressure washers or garden hoses |
| Soft-bristle brush | Steel wool or abrasive scrub pads |
| Mild sauna-safe wood cleaner | Bleach, ammonia, or commercial disinfectants |
| 50/50 white vinegar and water | Pine-Sol, Lysol, or anything heavily scented |
| Baking soda paste for stubborn marks | Furniture polish, mineral oil, household oils |
| Fine-grit sandpaper (150-180) for old stains | Paint, varnish, polyurethane on interior wood |
The one place we’ll diverge from a lot of guides: we don’t recommend bleach for mold even though some manufacturers list it. By the time mold has gotten established enough to need bleach, you have a ventilation problem that’s worth fixing at the root. (More on that below.)
Common sauna problems
“My sauna smells bad”
Three usual causes:
Trapped sweat in the wood. Most common. Wash benches with mild sauna cleaner, lift duckboards, and start showering before sessions and sitting on a towel.
Mold or mildew. Open the door and run the heater hot for an hour to drive out moisture. Inspect benches, ceiling corners, and under duckboards for visible mold. Wipe small spots with a vinegar-water solution. If it’s widespread or coming back, the room isn’t drying out between uses. Check that the inlet vent is open, the outlet vent is unobstructed, and that you’re cracking the door after sessions.
Burnt hair on the rocks. Smells exactly like it sounds. Run the heater hot, ladle a few cups of water over the rocks, and crack the door. The burn-off finishes in 20-30 minutes.
“My sauna smells like burning”
If it’s a brand-new sauna, that’s the rocks burning off mineral residue and the heater elements seasoning. It’s normal for the first 2-3 sessions. Ladle water and air the room out.
If it’s an older sauna and the smell is new, stop using it and check: dust accumulated on the heater elements (vacuum and wipe), an item that fell against the heater, or an electrical issue. If you can’t find an obvious cause, call an electrician.
“Should I leave the sauna door open after use?”
Yes, every time, for at least 10-15 minutes. This is the most important habit in sauna care. It dries the room and prevents almost every problem on this page.
“How do I get rid of mold in my sauna?”
Small spots: wipe with 50/50 vinegar and water, then run the heater hot with the door cracked for an hour. Sand any remaining stains with fine-grit sandpaper.
Widespread mold: this is a ventilation issue more than a cleaning issue. Open the door and run the heater for several hours. Then check that your inlet vent (low, near the heater) and outlet vent (high, opposite wall) are both clear. If the room still won’t dry between uses, you may need a small fan in the dressing room to pull air through. We can help diagnose this. Call us with photos.
“Are saunas hard to maintain?”
No. A residential sauna takes 5-10 minutes a week, plus an hour or two once a year. It’s the lowest-maintenance backyard structure you can own, easier than a hot tub by a wide margin. Most of the failures we see come from neglect over a decade, not from anything you can’t prevent with a basic routine.
When to call us
Most sauna care is straightforward enough that you can handle it yourself. A few things are worth a phone call:
- A heating element that has visibly failed or is heating unevenly
- Mold that comes back after you’ve corrected ventilation
- Wood that’s warping, splitting, or showing rot (rare in cedar and hemlock, common in cheap pine kits)
- Any electrical smell that doesn’t clear with normal burn-off
- A wood-fired stove with visible cracks, warping, or chimney damage
We’re at 612-505-9700 or [email protected]. If you bought your sauna from us, we have your install records and can usually diagnose by phone with a photo or two.
If you didn’t buy from us but have an SSC sauna in the family or a unit installed by a previous owner, we’ll still help. We’ve talked plenty of people through care on saunas we never sold.
A word on residential vs. commercial
Everything in this guide is written for residential use. Commercial saunas (gyms, hotels, spa locker rooms) run a different schedule. Higher use, more bathers per day, mandatory disinfection cycles, often a deck-drain layout that needs daily attention. If you’re maintaining a commercial sauna, the daily wipe-down is mandatory and the annual deep clean usually becomes a quarterly one.
The short version
If you only remember three things:
- Crack the door after every session.
- Wipe the benches once a week.
- Replace cracked rocks once a year.
Everything else is small refinements on top of those. A sauna treated decently lasts 30-40 years and looks better at year 20 than it did at year one. The wood develops a depth of color you can’t get from anything new. That patina is the goal, not something to fight against.
Looking at a sauna and wondering what’s involved long-term?
We’re a Finnleo and World Sauna Group dealer with 8-12 saunas in the Cokato, Minnesota showroom. Drop in for a free 30-minute sauna and we’ll walk you through care for whatever type you’re considering: traditional, wood-fired, infrared, or a custom build.
Contact us online or call us at 612-505-9700.