Site investigation report not correct - and now?

Hello everyone,

Thank you for your feedback. Briefly in advance, we are not seeking damages or anything like that; for us, it is about finding a solution on how to solve the problem cleanly and quickly – however, with the condition that not all responsibility is denied from the outset. At today's appointment, the geologist explained the problem to us (of course, he did not admit any fault), and possible solutions were also discussed with the construction company. Theoretically, our previous solution with the soakaway shaft might still be possible, but there is a risk that we could end up standing in water during heavy rainfalls. The second idea was a waterproof base slab + reinforced basement wall coating, with a similar risk and difficult execution for a semi-detached house. That would then mean a white tank + recalculation of the statics. All options will now first be calculated, and then another appointment will take place.

Where the water actually comes from is not yet entirely clear, possibly from a well on the other side of the street or the old sewer; it only leaks out on a few square meters. We will know more on Monday when the sewer work starts. Maybe we are lucky and something simpler to solve will be found. From my point of view, in the worst case we probably will not avoid the costs of the white tank, because if the report had already given the recommendation, we would have had to pay for it. Costs that now additionally arise (statics, etc.) will be clarified with the geologist to see if he shows any leniency here, after all, the statics were calculated based on his report and are now required again.

So, now first a cold beer, wish you a nice evening.

Best regards
Crazy

Hello everyone,
after a few days have passed, I wanted to share the outcome of our problem for those who are interested. We were actually already prepared for a [weiße Wanne] and the associated additional costs, but after investigations, it turned out that the cause of the water ingress was an old pipe in the street, which had apparently been leaking for years. This was initially sealed, after which no more water ingress was detectable. A few days later, the pipe was opened again, and shortly after, water ingress was detected once more. This old pipe thus turned out to be the actual cause and has now been completely sealed. For us, of course, this is a huge relief, but those days were quite an emotional rollercoaster...

Best regards
Crazy

Oops ...

Written too fast. Congratulations on having overcome this first problem and that the expert was not mistaken. He certainly also pondered and googled the causes of the misjudgment.

I hope it doesn’t bother you if I briefly describe something here.

We also commissioned a soil survey. According to the geologist, everything should be no problem. On the day the excavation began, we were informed that sand had been found, a layer about 90 cm thick. The geologist was notified and it was decided on site that the strip foundation needed to be laid deeper. Clearly, it is too late to change anything now, but should the geologist have seen this?

What I also found quite excessive was that for 3.75 hours of total work time he charged 280 euros + 2 hours of travel time another 160 euros.

Actually, this follow-up visit should have been free since, in my eyes, he made a mistake that is now costing me more.

Or am I seeing this wrong?

We also commissioned a soil survey. According to the geologist, everything should be no problem.
On the day the earthworks began, we were informed that sand was found, a layer about 90cm thick. The geologist was notified and it was decided on site that the strip foundation had to be laid deeper.
Of course, now it’s too late to change anything, but should the geologist have seen that?

What I also found quite exaggerated: for a total working time of 3.75 hours, he charged 280 euros + for 2 hours of travel time another 160 euros.

Actually, this follow-up visit should have been free because, in my eyes, he made a mistake that is now costing me more.

Well – I already wrote further up in the thread that the drillings can only provide a spot assessment.
Does the sand layer extend under the entire house foundation area or only in a certain area? Was drilling done in that area too?

If drilling was done there, I agree with you. Then the geologist should have seen it.
If he placed his drillings elsewhere, it was simply unlucky. The geologist is not a clairvoyant and therefore does not know what the entire subsoil looks like. I assume there are guidelines on how the drillings should be arranged on the property to achieve the greatest "predictive accuracy." Still, deviations can occur.

If the geologist originally placed the drillings at the spot where the sand layer was later found, in my layman’s opinion, the additional costs should not be passed on to you. If the sand was found elsewhere, charging for it would be legitimate.

However, I do not know to what extent there is something like a warranty for geologists.