ᐅ Base/Foundation for a Hot Tub

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 it by about 30cm (12 inches). The soil is fairly compacted and clayey. Which method or construction would you recommend?

Interestingly, I also want to install a heat pump in the garden. Which model, etc., do you have?

Either a concrete slab or paving stones. Since this will probably be some kind of wellness area, I would lean towards paving stones. You would be laying slabs and such there anyway. There are permeable paving stones... I would tend to choose those to prevent water from pooling.

Another very stylish option is to embed it in the ground and install wooden decking all around, but tastes vary.

And ideally, insulation should be applied to the foundation or slab. This significantly reduces heat loss.

hampshire schrieb:

Softub hot tub

Already purchased?

Just checked the specification sheet. They only have a 1.4 kW power connection. So you can't expect impressive heating performance (winter operation!) or strong massage intensity. Especially considering the list price (what is the street price?).
I think I would have chosen something else.

We excavated about 30cm (12 inches) deep for our heat pump (for 6 people, filled with approximately 2.5 tons), then backfilled with recycled concrete sand and compacted it. On top of that, we poured a 20cm (8 inches) concrete slab and laid 8cm (3 inches) XPS insulation boards on it. However, this slab is also recessed into the raised veranda and therefore needed a plinth to reach the required height. In your case, you would simply have to dig deeper accordingly.

I would actually be concerned about uneven settling if you don’t excavate first and create a stable base with gravel or similar material. On the other hand, with a freestanding soft tub like this, you could also take a bit of a "risk" and just place a few XPS boards underneath; if it settles over time, you simply drain the water, move the heat pump aside, and add more material.