[QUOTE="Mizit, post: 231864, member: 28522"]
Unfortunately, we had not lived in the house for four weeks when we had the first major damage. To explain briefly, the shower tray sags slightly at one spot under load. Even with the few showers we had taken, we noticed this "brief give" a few times but didn't think much of it. There was also no corresponding indication of this from the previous owner. This sagging causes a crack in the silicone joint on the wall. Depending on how the shower spray is positioned, quite a bit of water runs in there, and that exact spot under the shower was apparently not properly sealed with silicone on the wall. As a result, water ran into the ceiling and came out again in the hallway on the ground floor.
1. A shower tray must not move. It should be replaced. Otherwise, the damage will happen again.
2. The silicone joint is not a waterproofing; there is a separate composite waterproofing for that.
3. Has the moisture in the masonry and screed already been measured? What type of screed do you have in the bathroom and the adjacent rooms?
4. The building insurance is not responsible, and I would also be surprised if the contents insurance paid anything. But okay...
Maybe it was not only due to a leak but also a damage in the pipe system. Therefore, this must be thoroughly checked.