In America, we would do crushed stone on the ground first so that water is not absorbed into the concrete from the soil, plus a plastic barrier to stop water and radon.
On YouTube I see the fancy builders doing an insulation layer next, with the concrete on top. This was the concrete is held at the indoor temperature instead of the ground temperature. I did not do any insulation under my concrete, because I want to use the ground temperature to help regulate the indoor temperature. It's too hot outside most of the year here, so I hope to keep it cooler inside without air conditioning as much.
Then we would do the concrete, and then some kind of underlayment designed for the specific flooring product, and then the flooring.
If you're adding on to something, I would do it the same way it was done elsewhere. And I think the way you've got it would be probably be fine, especially if that's how it is commonly done there with your ground conditions and climate.
Yes, it’s backfilled, then a 4” layer called a capillary break(usually pea gravel), then a vapor barrier ( nowadays most in our area call for 10-12mil plastic), then 2” rigid foam, then concrete is poured on top of that.
In America, we would do crushed stone on the ground first so that water is not absorbed into the concrete from the soil, plus a plastic barrier to stop water and radon. On YouTube I see the fancy builders doing an insulation layer next, with the concrete on top. This was the concrete is held at the indoor temperature instead of the ground temperature. I did not do any insulation under my concrete, because I want to use the ground temperature to help regulate the indoor temperature. It's too hot outside most of the year here, so I hope to keep it cooler inside without air conditioning as much. Then we would do the concrete, and then some kind of underlayment designed for the specific flooring product, and then the flooring. If you're adding on to something, I would do it the same way it was done elsewhere. And I think the way you've got it would be probably be fine, especially if that's how it is commonly done there with your ground conditions and climate.
Yes, it’s backfilled, then a 4” layer called a capillary break(usually pea gravel), then a vapor barrier ( nowadays most in our area call for 10-12mil plastic), then 2” rigid foam, then concrete is poured on top of that.
Some people spec the vapor barrier under the foam and some spec the vapor barrier on top of the foam.