AC-04Locate cables and pipes, and know how to isolate themCables and pipes can run almost anywhere in a wall, not just in the usual safe zones, so use a detector and still treat the wall as live until you prove otherwise. Before you drill, find your stopcock — 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 about what's behind the wall, isolate the circuit at the consumer unit before drilling, and turn off the water at the stopcock before cutting into anything that could carry it.