The most important thing is that the place of placement is even and stable. It can be placed on wooden decks or lowered (then bear in mind that service hatches must be accessible, can be repaired so that parts of the tire can be removed all around), tamped gravel with a hard insulation to remove unevenness also works well as well as cast foundations, slabs or the like.
A water-filled spa bath with 6 people weighs 2000 - 2500 kg. The area it takes up is 4 - 5 m². Distributed per m² becomes it 500 kg or 50 gr per cm2. A normally built wooden deck and its support structure should not have any problems with it the load. But if you are unsure about the strength, ask a carpenter just to be safe.
TopSpa Medio installed in terrace
Extra room has been made for the lid lifter