Is it sensible for the expert to inspect the base plate?

Hello everyone,

in mid-December, the foundation slab for our single-family house was poured. The civil engineering company is a family business from the region that enjoys a very good reputation. The preparations also went super smoothly (they even started with the earthworks, although we hadn’t even signed the contract yet) and we generally didn’t have to worry about anything (they also took care of various clarifications with the municipality because they already knew each other).

On the day the foundation slab was poured, unfortunately, we were all very sick (middle ear infection with nearly 40 degrees fever) and therefore could not go to the construction site (just getting to the bathroom was a torment). I went there the next day to take a quick look. The foundation slab was completely covered, which we had expected because it was snowing heavily at the time and the temperature dropped to -12 degrees at night. The civil engineering company regularly works under such conditions; at our previous landlord’s place, they had poured the foundation slab one day before Christmas also during heavy snowfall.

So far, so good. However, when we went back to the construction site about a week later (we do not live on site), some parts of the covering foil were no longer there. We suspect that some children played around and removed the foil, because it really couldn’t have come off due to the wind since the foil was very well secured.

Now we unfortunately do not know exactly when that happened, so whether the foundation slab was already frost-proof at that time or not, and we are wondering if that might have had any negative effects. Visually, everything looks fine and, for example, I couldn’t detect any cracks. The foundation slab will then be inspected by our site manager in spring, but I assume he will mainly check whether all dimensions are correct.

Therefore, I wanted to ask here whether you would recommend having the foundation slab inspected by an expert. I have heard that, for example, TÜV Süd does something like that. Or is that wasted money because they basically only measure and check whether the foundation slab has cracks (as I said, I couldn’t see any; everything looked good to me, but I am also an absolute layman)?

Thank you very much in advance for your help!

Basically, an acceptance before pouring the floor slab would have been more sensible. Because only then can the inspector see if enough steel has been used, as the general contractor (GU) likes to save here. The topic "pouring the floor slab in frost" was discussed here recently. Just use the search function.

Maybe I used the term GU incorrectly. We are building with a prefabricated house provider, but they have nothing to do with the foundation slab. We organized the excavation and groundwork ourselves through the civil engineering company. So I have absolutely no concerns that they used too little steel or anything like that. Maybe it's naive, but they really have an excellent reputation here in the region, and we have only heard positive things from everyone who has worked with them. What I'm more concerned about is whether an expert could still detect possible damage caused by the cold temperatures afterwards.

Who did the grounding? A specialist? Is it properly documented for the electrician who is doing your power connection? Before pouring the foundation slab, an expert would have been better.

Since the site manager accepts your on-site work before he erects the house, it can happen that he complains about defects if there are any. It doesn't bother him, quite the opposite, if he sets his house on a faulty base plate and then there are problems, he's the one in trouble in the end... because he is the expert, he should have recognized it...

If I remember correctly, there are also certain safety factors in building construction. No structural engineer calculates and designs a foundation so that it just barely works if the shell builder follows everything meticulously. They're not completely stupid either.

Also with the foundation earth electrode. That's not so critical in the TN-C-S system, it would be bad in the TT system.

Who did the grounding? A professional? Is it properly documented for the electrician who will connect your power supply?
Before pouring the base slab, an expert would have been better.

The grounding was done by the civil engineering company. Our site manager was also on site and went through everything with the civil engineering company. Since both our prefabricated house provider and the civil engineering company come from the region, they regularly work together.

I am grateful for any advice, but tips like "it would have been better to ... beforehand" unfortunately do not help me at all. As I said, the civil engineering company regularly works in snow and cold temperatures, and we have only heard positive feedback from friends and acquaintances who had the base slab poured under similar conditions. So I do not question whether the civil engineering company did everything correctly. It is only about whether frost damage could have occurred due to the possibly premature removal of the foil and whether an expert could recognize this retrospectively.