How to Deep Clean a Sauna
A periodic deep clean tackles the benches, floor, drain, stones and heater area. Here is a step-by-step deep clean to keep a sauna fresh and hygienic.
The short answer
A sauna deep clean goes beyond the weekly wipe: sand the benches, clean under them and the floor and drain, refresh the stones, clear the heater area, and dry everything thoroughly. Do it every month or two, and fully at least once a year.
Regular wiping keeps a sauna fresh day to day, but every so often it benefits from a proper deep clean — the kind that reaches under the benches, refreshes the stones, and resets the whole room. Here is how to do it.
Before you start
Let the sauna cool completely, remove everything loose — duckboards, bench mats, backrests — and open the door and vents. You will clean these separately.
The deep clean, step by step
- Sand the benches. Because sauna wood is unsealed, lightly sand the bench boards with the grain to lift sweat stains, greying and odour, restoring a fresh surface.
- Clean under the benches and the floor. Sweep out grit, then wash the floor, corners and under-bench areas with warm water and a mild sauna cleaner. Clear the drain if fitted.
- Wash the removables. Clean duckboards, mats and backrests, and dry both faces fully.
- Refresh the stones. Restack the stones, discard cracked ones, and clear grit from the element bed or firebox.
- Clear the heater area. Remove dust and debris around the heater; for a wood stove, remove ash and check the firebox.
- Dry everything thoroughly. Run the heater and ventilation until every surface is dry before refitting the removables.
How often
A deep clean is genuinely satisfying: fresh-sanded benches, a clear floor and drain, clean intact stones, and a room that smells of warm wood. Fold it into your seasonal maintenance checklist, and the sauna stays a pleasure to walk into for years.
Why the deep clean matters
A deep clean does more than freshen the room — it resets the parts of a sauna that quietly degrade with use. Sanding the benches removes sweat-soaked wood before it becomes a stubborn smell; refreshing the stones clears the grit that chokes airflow and dulls the löyly; and clearing under the benches and the drain removes the trapped moisture where odour and mould begin. Skipped for too long, these build up into problems that a quick wipe cannot solve.
Tie the deep clean to a season, ideally before the cold months when the sauna gets its heaviest use, and the room stays consistently fresh year-round. Between deep cleans, the everyday habits carry the load: sit on a towel, wipe down after use, and dry the room with the vents open. Do those, and each deep clean is quick and satisfying rather than a rescue mission — leaving fresh-sanded benches, clean stones, and a room that smells of warm wood.
Frequently asked questions
How do you deep clean a sauna?
Cool the sauna, remove the loose items, then sand the benches, clean under them and the floor and drain, wash the removables, refresh the stones, clear the heater area, and dry everything thoroughly. Use only warm water and mild sauna-safe cleaners.
How often should you deep clean a sauna?
Every month or two for a regularly used sauna, and a full deep clean at least once a year — ideally before the cold season when the sauna gets its heaviest use.
What is the difference between cleaning and deep cleaning a sauna?
Everyday cleaning is a wipe-down and dry after use; a deep clean reaches under the benches, sands the wood, refreshes the stones, clears the heater area and drain, and resets the whole room.
Can you use strong cleaners for a sauna deep clean?
No — even for a deep clean, use only warm water and mild, sauna-safe cleaners. Bleach, solvents and scented products are absorbed by the bare wood and vaporised into the air when the sauna is heated.
Should you refresh the stones during a deep clean?
Yes — a deep clean is the ideal time to restack the stones, discard cracked ones, and clear grit from the element bed or firebox, restoring airflow and the löyly.
Do you sand the benches in a deep clean?
Yes — light sanding with the grain lifts sweat stains, greying and odour from the unsealed bench wood, restoring a fresh surface. It is a key part of a thorough deep clean.
Why is a periodic deep clean important for a sauna?
It resets the parts that degrade with use: sanding benches removes sweat-soaked wood before it smells, refreshing stones clears grit that dulls the löyly, and clearing under benches and the drain removes trapped moisture where odour and mould begin.
When is the best time to deep clean a sauna?
Tie it to a season, ideally before the cold months when the sauna gets its heaviest use. Between deep cleans, everyday habits — towel, wipe-down, and drying the room — keep it fresh and make each deep clean quick.
