Soggy Situation

Things are going well here. We've finally got a fully-furnished apartment, and now we're attending to the finer details. However the decoration process has come to a temporary halt because it makes me nervous to put any nails or screws in the walls. Yesterday our drill hit a hollow space which we did not expect to encounter in these very solid German walls. Unfortunately, it wasn't just any hollow space, but one that produced a small stream of water that trickled down the bedroom wall. And not just any water, but water that was on its way from the upstairs apartment's toilet down to the sewer. A plumber came, chiseled a hole in the wall to get a better view of the pipe, put a temporary patch on it, and said he'll come back next week with the proper equipment to remove larger chunks of wall, cut the pipe and replace a section of it, and re-build the wall. He will also bring a handy device that senses where it's safe to put a nail or screw.