With very minimal maintenance you can keep your sauna room looking great. The following is only a general guide.
Do not paint, varnish, or stain the inside of your sauna. The wood must breathe to absorb and release heat and humidity. Finishes can trap heat, release fumes, and reduce the natural warmth and comfort of the wood.
Door handles and floor boards are an exception to step #1. These two points of the sauna can get dirty easily. To make cleaning easier, you can treat the handles and floor boards with a good wood sealant or polyurethane finish.
The simplest method of sauna maintenance is to keep a hand brush in the sauna. The last person out dips the brush in the water bucket (plain water), and does a quick scrubbing of the benches, walls, backrests, etc. This 30 to 60 second ritual will keep your sauna looking great for years.
After you’re finished using the sauna, and your cleaning process is complete, prop the duckboards off the floor. Leave the sauna door open, to air it out completely. The heat remaining in the rocks and in the wood should dry the sauna completely, and even can help dry down the shower area, if it is adjacent to the sauna room.
If dirt or sweat stains appear, scrub with a hand brush and warm water mixed with mild detergent. To restore your benches, lightly sand them once a year to bring back their original color. For any mold (such as on duckboards), clean with warm water and a bleach solution like Clorox or Hi-lex.
Depending on how often you use your sauna, occasionally wet-mop with a liquid deodorizing cleaner such as Lysol or Pine-Sol. With these simple maintenance tips your sauna will stay inviting, fresh smelling, and enjoyable to be in. The main rule is: ENJOY