Base for whirlpool

In a few weeks the Softub hot tub will arrive. It requires a level surface. I have a flat spot on the property and only need to level about 30cm. The soil is quite compacted and clayey. Which method / construction would you choose?

Interestingly, [wir] also want to set up a WP in the garden. Which model etc. do you have?

Either a concrete slab or paving. But since this will presumably be some kind of wellness oasis, I would tend to go for paving. You would be laying slabs etc. anyway. There is permeable paving... I would tend to use that so the water doesn't pool.

What also looks really nice is if you embed it in the ground and install wooden decking all around, but tastes vary.

And preferably insulation on the foundation/paving as well.
Thus significantly less heat loss.

Softub Whirlpool

Already bought?

Just looked at the datasheet. They only have 1.4kW connection power. So you can't expect great heating performance (winter operation!) or intense massage. And that at the list price (what is the street price?). I think I would have chosen something else.

We excavated about 30cm deep for our heat pump (6 people, filled ~2.5 tons), then backfilled with RC sand and compacted. On top of that, a 20cm concrete slab was formed and on top of that, 8cm XPS insulation boards were laid. However, it is also recessed in the elevated veranda and therefore needed a pedestal to reach the necessary height. In your case, you would just have to dig correspondingly deeper.

I actually have concerns that it might settle unevenly if you don’t excavate beforehand and create a stable base with gravel or something similar. On the other hand, with such a freestanding soft tub, you could also just play it "risky" and simply place a few XPS boards underneath; if it eventually settles, you just drain the water, move the heat pump to the side, and add material.