The most common water damage problem that we see in newer homes, come from the use of push-fit plumbing. Occasionally if pipes are not pushed fully home into the fittings or if cheap fittings are used, water can seep past the O-ring seal. The first you’ll know of this leak is when you see a slightly dark line appearing on the ceiling, where the water is collecting usually adjacent to a ceiling joist. By this time, there’s usually quite a lot of water in the ceiling, the joists, and often in the walls too. So if you see a small dark line on your ceiling, don’t just paint over it, get someone round to find and fix the source of the problem, and then make sure that all the moisture is completely removed before re-painting.