How to Clean and Maintain an Infrared Sauna: A UK Owner’s Guide

Learning how to clean an infrared sauna is the single best thing you can do to protect your investment and keep every session hygienic. An infrared cabin is a warm, wooden, humid box that you sweat inside several times a week, which is exactly the environment where odours, salt residue and mould can build up if it is neglected. The good news is that maintenance is quick and needs almost no special kit. This UK owner’s guide covers the after-session routine, a simple weekly clean, the products to use and avoid, and how to keep the wood and glass looking new for years.

Why regular cleaning matters

Sweat leaves behind salts and skin oils that soak into untreated wood, dull the benches and, over time, cause staining and a stale smell. Because an infrared sauna warms your body rather than the air, the cabin does not reach the scorching temperatures of a traditional sauna, so it does not “bake” itself as dry between uses. That makes a short cool-down and wipe-round after every session more important, not less. Stay on top of it and the wood ages gracefully; ignore it and you invite mould into the corners and under the benches.

After every session: the two-minute routine

Sit on a towel. The easiest maintenance is prevention. Always use towels on the bench and floor to catch sweat before it reaches the wood.
Wipe down the benches and backrest. Use a clean, damp microfibre cloth to wipe any surface your skin touched. Plain warm water is enough for a daily wipe.
Leave the door open to dry. Prop the door open and, if fitted, run the cabin’s fan or leave the room ventilated so the interior dries fully. Trapped moisture is the main cause of mould and odour.

Weekly clean: what to do

Once a week, or after heavy use, give the cabin a slightly deeper clean. Make sure it is switched off and cool first. Wipe all the wooden surfaces, the floor and the door frame with a cloth dampened in warm water and, if needed, a little mild, unscented soap or a solution of white vinegar diluted in water (roughly one part vinegar to four parts water), which deodorises and discourages mould. Wipe the same surfaces again with a cloth wrung out in clean water, then dry off and ventilate. Check the corners, the underside of benches and the floor slats, which are the spots most likely to hide damp.

Products to use and avoid

Keep it gentle. Untreated sauna wood is porous and does not like harsh chemistry.

Use: warm water, mild pH-neutral soap, diluted white vinegar, and a soft cloth or soft brush. A dedicated sauna cleaner is fine if you prefer one.
Avoid: bleach, ammonia, strong household cleaners, bactericidal sprays and anything heavily perfumed. These can bleach or stain the wood, leave residues that heat up and smell, and are not something you want to breathe in a warm cabin.
Never varnish or seal the interior wood unless the manufacturer tells you to. The bare timber is meant to absorb and release moisture, and coating it can trap damp and release fumes when heated.

Dealing with stains, marks and rough patches

Sweat stains and scuffs on the benches can be lifted by lightly sanding along the grain with a fine-grit sandpaper (around 220 grit). Sand only the affected area, wipe away the dust, and the fresh wood will blend in. This is normal, occasional maintenance for any wooden sauna and returns the surface to a clean, matt finish without any chemicals.

Cleaning the glass, controls and heaters

Wipe glass doors and panels with a damp cloth or a little diluted vinegar for a streak-free finish; avoid spraying cleaner directly near the control panel. The infrared heater panels themselves need only an occasional gentle dust with a dry or barely damp cloth once cool, never a wet wash. Wipe the control panel and any audio or light fittings with a slightly damp cloth only. If you ever need to clean near the heaters or electrics, switch the sauna off at the isolator or unplug it first, and keep water well away from electrical parts. The charity Electrical Safety First has clear guidance on working safely around fixed appliances.

Preventing mould and odours

Almost every sauna smell or mould problem comes down to moisture that never dried out. To prevent it: always towel down, always leave the door open to air after use, keep the room itself ventilated, and do the weekly vinegar wipe. If a musty smell appears, clean thoroughly with the diluted vinegar solution, dry the cabin completely, then run it empty at temperature for 20 to 30 minutes to drive off the last of the damp. Persistent black mould in the timber may mean a bench or slat needs replacing.

Floors, water spots and hard-water areas

Do not forget the floor, which collects the most sweat and dust. Wipe it with the same damp cloth and mild solution, and lift out any removable duckboard or floor slats to dry separately. In hard-water parts of the UK, wiping surfaces dry after cleaning stops white limescale spotting on the glass and fittings, and a quick buff with a diluted vinegar cloth removes any that appears. Keep a dedicated set of cloths for the sauna so you are never carrying kitchen or bathroom cleaner residues into the cabin.

A simple maintenance schedule

Every session: use towels, wipe touched surfaces, air-dry with the door open.
Weekly: damp-wipe all wood, floor and frame; ventilate and dry.
Monthly: check corners and under benches for damp, sand out any stains, dust the heaters.
Yearly: inspect the fixings, the door seal and the electrics, and deal with any worn timber.

Frequently asked questions

How often should you clean an infrared sauna?

Do a quick wipe-down and air-dry after every session, a fuller damp clean once a week, and a closer inspection for damp and stains monthly. Light, regular cleaning is far easier than tackling built-up residue or mould later.

What is the best thing to clean a sauna with?

Warm water with a mild, unscented soap or a diluted white vinegar solution is ideal. Vinegar deodorises and discourages mould without leaving a scent that will bake off when the cabin heats up. Avoid bleach and strong chemical cleaners.

Can you use disinfectant in an infrared sauna?

Harsh disinfectants and bleach are not recommended on bare sauna wood, as they can stain the timber and leave fumes. A diluted vinegar wipe handles day-to-day hygiene; a mild, sauna-safe cleaner is fine if you want something stronger.

How do I stop my sauna smelling musty?

Musty smells mean trapped moisture. Towel down after use, leave the door open to dry, keep the room ventilated, and do a weekly vinegar clean. To clear an existing smell, clean and dry the cabin fully, then run it empty at temperature to drive off remaining damp.

Should you seal or varnish the wood inside a sauna?

No, unless the manufacturer specifically recommends it. The interior timber is designed to breathe and absorb moisture. Sealing or varnishing can trap damp and give off fumes when heated. Light sanding, not coating, is the correct way to refresh the surface.

For more on building and running a home wellness space, visit The Shape House.