Is a new foundation slab necessary for new construction, or is demolition required?

Hello everyone,

Yesterday, the concrete slab for our single-family house was poured (by a third-party company). About 2 hours after completion, we noticed that at the edges of the formwork there were settlements and (potential) gravel pockets in the concrete (see pictures).

Probable cause: You can see in the pictures that water and cement leaked out from under the formwork and accordingly appeared as wet cement puddles next to the formwork. We suspect this is because the PE film was not laid all the way to the edge of the formwork (as visible in the pictures) and also had gaps/cracks in the rest of the area. By the way, this is WU concrete 25/30.

Now to our question: Is this concrete slab usable/repairable as is, or should we insist on a dismantling? Our concern is that the slab will not be watertight (due to incorrect consistency: gravel pockets) and that the house walls at the edge of the slab will not find stable support.

We would greatly appreciate your opinion/feedback!

What does your expert who accompanies your construction say. If you don't have an expert, then organize one who will guide you.

Looks like nonsense. Can be reworked.

Everything else will be told to you by your expert.

For our single-family house, the floor slab was poured yesterday (by a third-party company).

Who is such a penny-pincher at the wrong end to have this done by a third-party company (here probably more of a janitor all-round service than a specialist company)? A floor slab belongs in the scope of services of the construction contract with the general contractor / house manufacturer. Gravel nests are more likely caused by a half-hearted mix of the concrete than by water seeping out of the cement slurry. That the result could still have been "WU" (waterproof) is something even the Easter Bunny would only believe before a hangover breakfast.

Now to our question: Is this floor slab usable/repairable as it is, or should we insist on a dismantling?

And now to the counter-question: where do you get the idea that such a cow company is financially strong enough to survive even a warranty case?

You should urgently hire a construction expert to accompany the build, and preferably also a lawyer to review your construction contract once more (in case you also chose the general contractor / house manufacturer just as cleverly).