Your sauna base must meet two key requirements:
It must be completely level.
It must support the full weight of the sauna and users.
Most saunas bases must be able to withstand twice the weight og the sauna itself. For example, when laying a base for saunas weighing above 400 kg, plan for an additional 400 kg for occupants — a total of around 1,000 kg+. Suitable base materials include concrete, patio decking, tiles, or asphalt — as long as the surface is flat and stable.
Check out our guide on different sauna bases here and we strongly advise you to hire a professional.
Avoid installing the sauna on a slope or in an area prone to water pooling.