Inner wall damp from rain

But I'm not going to do that, the construction company can do it nicely.

The construction company will most likely not do this voluntarily; they apparently are already trying to solve the problem in a cost-effective way until the warranty expires. However, the impairment of ventilation might even worsen the problem if moisture can no longer escape through this route. A missing seal will probably only be expensive to repair later; I hope for your sake that it is something else. Only if several houses are affected do I tend to believe in such a systematic execution error. Probably at some point an expert will have to open the wall to document the error. Maybe the construction company will come to their senses and actually fix the defect properly. In any case, I would conduct further communication with the construction company in writing and document the process thoroughly (maybe also take useful photos yourself).

I only do it in writing anyway. Otherwise, they twist your words. Fortunately, I have retained a small amount from the final invoice due to another matter (unfortunately only). Thus, I might be able to apply a bit of pressure.

Hello.


Did "someone" perhaps skip the sealing above the first row of stones .... ?

Rhine greetings

In itself, that would not necessarily lead to the described damage pattern from my point of view. For example, in all houses in our neighborhood, sealing is also only done beneath the first row of stones. However, I would suspect that this sealing was also "optimized" (i.e., saved) here. :-(

If it is at three houses, I would directly involve an expert. You can share the costs for that.

I can only tell you that we have this problem too. However, we have not moved in yet. For us, the moisture actually comes or came through the ventilation grilles. For us, it is also the tilt side and the property is on a slope. When it rained heavily, the clay soil loosened and basically clogged the ventilation grilles and let a lot of water into the house. That was still basically in the shell condition. Afterwards, we dried the base slab and the walls as much as possible and had plastering and screed laying done. Well, and now, exactly at the spots you described, moisture is appearing in the lower area. We have already had a professional come and it is clear that the transition from the base slab to the wall was not dry enough during plastering or screed laying. And now it is drawing moisture. We will try to get it dry by heating. In the worst case, a special drying under screed will have to take place. Make sure to have it thoroughly checked!