ᐅ Assessment of Building Site – Does the Excavator Refer to Natural Topsoil?

In my opinion, the civil engineering contractor is very competent. I only showed the photos to an independent third party. They said, "That’s clay, it needs to be removed"… it’s not natural soil or anything like that. That made me a bit worried… Now I’m wondering if they should have dug even deeper. Do you think I’m overthinking this? In the end, he also wants to perform a “bearing capacity test” to confirm the soil’s load-bearing ability. Is that a guarantee that the soil is suitable for construction?

He will not build on clay soil but will replace the clay with sand to a depth of about 80 cm (31 inches). He will compact it using a vibrating plate, and concrete will be poured on top.

No. Sand was placed directly on this soil. The clay was not removed. If it is clay, that is...

Only the topsoil was removed...

I still don’t fully understand the problem. You consider your groundworks contractor to be very competent. He gives you the good news that the soil is stable. Then a third party unsettles you with a comment about a photo?

That's exactly it. Yes, the photo assessment makes me uncertain. Can you not tell from the photos whether the soil is reasonably load-bearing?

How is one supposed to see that from the photos? Please post your soil report along with the foundation recommendation!