SR-04Check for cables and pipes before you drillCables and pipes can run almost anywhere in a bathroom wall, not just in the obvious zones, so sweep every marked point with a detector. Even with a clear reading, treat the wall as if something is there until you prove otherwise — detectors miss cables that are deep, in metal conduit, behind metal-backed plasterboard, or outside the normal safe zones, and a metal stud frame can throw a cheap detector off completely. Find your stopcock now, usually under the kitchen sink, and check it turns freely so you can shut the water off fast if you hit a pipe. If you have any doubt at all, turn off the relevant circuit at the consumer unit and the water off at the stopcock before you drill.