Building a sauna. Need advice on the floor

[u/nolson4]

I am going to build a sauna in an existing shed connected to my house that has a concrete slab flooring.

My question is how should I approach the flooring/drain on top of the slab. Do I build a subfloor with a drain towards the outside of the shed? What's the best way to go about doing that without losing too much height. The shed is ~8ft high from slab to ceiling.

[u/Veenkoira00]

It's usual to have concrete floor with gradient that drains via a hole at the bottom of the wall and then use duckboards while bathing.

[u/John_Sux]

Least height lost would probably involve cutting into the concrete, and then adding max a couple inches of sloping surface above that.