Are butt joints in ready-mix concrete basements acceptable?

So,

: It's a ceiling element. The elements form a box with the walls, reinforced on top, onto which in-situ concrete is poured. That creates the basement ceiling and "fills" the hollow exterior walls. I don't know what it's called, hope it's understandable.

The supposed acceptance today turned out to be a site meeting between the general contractor's site manager and me. Apparently, the acceptance is not done directly by the basement builder... The general contractor's site manager checked all the measurements to see if anything stands in the way of "placing the house on top." I did not sign any acceptance protocol.

The general contractor's site manager talked to the basement builder by phone and found out how the whole thing happened. After placing the element, the chain got caught on the reinforcement while pulling it up and apparently lifted it a bit, whereupon it then dropped down and got the crack.

I also spoke with the district manager of the basement builder. The crack is unproblematic since it is in the direction of floor tension(?) / opposite to the reinforcement direction(?), so basically like a joint. Structurally, it should be no issue, and I will get a written statement/clearance/declaration/whatever from the structural engineer. I had to interrupt the conversation due to an appointment; we will talk again tomorrow.

Today I took more photos. Everything is now filled in. How deep, I do not know, though. Maybe I'll drill into such a filler joint to have a look. Otherwise: 2 walls and 1 door slightly off level, two corners slightly out of right angle. No idea what the tolerances are there.

What options do I have now?

As mentioned, a formal acceptance is normally not planned. I only have a "construction status assessment" form. I can (and will) enter "remaining work/notes" there.

Actually, I want to quickly bring in a building expert who will fictively accept the basement with me or simply professionally record the defects again. And also tell me if the basement builder is talking nonsense. I think he then also knows what to do next.

Any other tips?

Alright, I'm done for today.

Hi,

Maybe I can help better with a few more pictures. If possible, I’d be happy to try. One question in advance:
The walls are not concreted beforehand but together with the ceiling?
Is water expected from the outside there?

In principle, the joints in both the walls and ceilings are normal and unproblematic. A "Drängebrett" should be dowelled there so that the concrete doesn’t leak out.

If I can support you from a distance, I’ll try.

Please take pictures from multiple perspectives and also from above the ceiling and into the walls. Also walls from the outside are welcome.

Best regards,
Jann

If I can support you from a distance, I'll try.

Thank you very much! I will then post a few from yesterday when I have time.

Find yourself a competent construction supervision; it is a worthwhile investment.

The walls are not concreted beforehand but together with the ceiling?

The exterior walls were hollow and were concreted with the ceiling.
The wall in the photo, however, is an interior wall.

Is water from outside to be expected there?

Groundwater is far away. We are installing drainage against rainwater.
Footings and walls are made of WU concrete, C25/30 grade (whatever that means).

Please take pictures from several perspectives and also from above of the ceiling and inside the walls. Also walls from outside if possible.

Photos from the inside are no longer possible, it has already been concreted.
But I will gladly upload some more photos when I am at the PC. Somehow that doesn’t work from my phone.

Okay, that the walls are concreted together with the ceiling is not something I know like that, but if nothing opens up downstairs due to the increased concrete pressure, then everything is fine.

FuPl and walls are made of WU concrete, C25/30 grade (whatever that means)

Yeah well, difficult topic. WU concrete basically does not exist or is initially of little use. The construction must be watertight. But if only rainwater, i.e. load case "temporarily ponding seepage water," is present and you have drainage for that, maybe more is not necessary. What worries me are the joints of the precast elements, because due to the construction method alone, a separation crack will occur unless an extremely strong reinforced rigid connection has been made.

It will probably stay dry, but I think that is due to the exterior structure and drainage, not the construction of the basement.
Maybe you can still consider sealing the joints explicitly from the outside.

Do you have a contract excerpt about what exactly is owed?

Find yourself competent construction supervision; it is a worthwhile investment.

Exactly! Often money is paid for things that do not get executed at all. And as a layman, you can never be sure that everything was really produced according to currently valid standards. There are traps lurking here as well, and often also some money, which is why the construction manager (independently) justifies his fee again. Even just for the feeling.

Best regards, Jann