ᐅ Slab foundation / suitable soil for foundation and related topics

Hello everyone,

I have a question that I would like to explain using a theoretical situation:

Assuming the soil on the building plot consists of 3 meters (10 feet) of topsoil/fill, so there is no load-bearing soil, and one wants the top edge of the concrete slab to be at the current natural ground level. What options are there for this?

My thoughts to explain what I mean:
- I have heard that a floating slab does not necessarily have to rest on load-bearing soil if at least X cm (Y inches) of soil underneath the slab is replaced with fill material.
- I have heard that, besides the floating slab, there is also the possibility of using footings/foundations.
- Is it always necessary to remove the full 3 meters (10 feet), or are there alternative foundation solutions?

As you can tell, I am not familiar with this topic and I am quite worried about the potential costs involved with 3 meters (10 feet) of fill/compaction.

Thank you very much for your input.

A geologist will give you a foundation recommendation.

Everything else is just guesswork.

Silent010 schrieb:
Assuming the soil of the building plot consists of 3 meters (10 feet) of topsoil/fill, so there is no suitable load-bearing soil, and you want the top of the foundation slab to be at the current natural ground level. What options are there for this?

Build a basement!

So, we had to replace one meter and then add another meter on top. With that amount of money, you could afford a solid garage. If it’s 3 meters, I would definitely build a basement, unless there are other technical solutions.