The flat above mine has had several water leaks over the past few years, most of the water ending up in my flat through the ceiling, to the point that part of it ended up falling down in a couple of places. It took them a long time to find the source of all the leaks and get them all sorted. They finally did and the owner above recently called his insurance to have repairs in my flat done. The builders came today and did a great job: I now have a new ceiling that doesn't look like it's going to fall on my head any minute. They need to come back next week, once the plaster is dry, to paint over it. Then it will be like new! Hurray!