Most of what follows is common sense plus a hundred years of accumulated convention. Newcomers occasionally break a rule on their first visit; nobody minds, as long as you're paying attention.
If we had to print one rule on the door, this would be it: your skin never touches the wood. Spread your towel under you. Sit on the towel. Use it to mop sweat off the bench when you leave. The wood lasts longer, the bench is hygienic for the next person, and you signal that you understand how this works.
Conversation is welcome. Loud conversation, less so. Reading aloud, group laughter, and arguments about politics are very much in the "save it for the cool-down room" category.
If you walk in and the room is silent, take that as the room's chosen mood and join it. If it's chatty, join in. Read the room — literally.
Throwing water on the stones — löyly — sends a wave of steam through the room. It is the single most heat-spiking act in the building. As a guest, ask the room before you do it: "Is anyone okay if I add a little?" A nod is enough. If anyone shakes their head, give it a few minutes and ask again later.
Use the small ladle. One scoop at a time, two at most. People have walked out red-faced from a newcomer's enthusiastic six-scoop pour, and they will remember.
Phones don't belong in the sauna. The heat shortens their lifespan, the cameras are an obvious privacy issue, and frankly, half the reason we're all here is to be unreachable for twenty minutes. Lock yours in your locker.
Shower with soap before each round. This is not optional. Many regulars also rinse off briefly after each round, before re-entering — both for the next person and for the heat-shock benefit. Whether you go nude or in swimwear, your sit-towel is the layer that matters.
The top bench is the hottest. The bottom is the coolest. People often migrate up as they warm up; if you're already on the top and someone climbs up beside you, give them room without making a production of it.
Don't lie down across an entire bench when other people are looking for a seat. Sit, leave space, and let the bench be shared.
Lower volume, slower pace. People are recovering. This is the place for quiet conversation, water, tea, the morning paper. Eating proper meals is for the café, not the cool-down room.
Newcomers are welcome and we love seeing them. As the host, you are responsible for explaining everything on this page before they walk in. Five minutes outside the door saves twenty minutes of awkwardness inside.
None of these are crimes. They're simply the small habits that signal "first time" to a regular. Avoid them and nobody will be able to tell.
Be clean. Be quiet. Be considerate. Use a towel. Beyond that, the regulars will gladly help if you look uncertain — most of us were uncertain on our first visit too.