PB-03Check for cables and pipes before you drillCables and pipes can run almost anywhere in a wall, not just in the usual safe zones, so run your detector across every mark first. Still treat the wall as if something is there even after a clear reading — detectors miss deep cables, cables in metal conduit, anything behind metal-backed plasterboard, and readings get unreliable near a metal stud frame. Before drilling, find your stopcock (usually under the kitchen sink) and check it turns, so you can shut off the water fast if you hit a pipe. If you have any doubt, isolate the relevant circuit at the consumer unit before drilling, and turn off the water at the stopcock before cutting into anything that could carry water.