WR-04Do your safety checks before you drillCables and pipes can run almost anywhere behind a wall, not just in the 'safe zones'. Use your detector, but still assume something is there until you've proved otherwise — detectors miss deep cables, cables in metal conduit, and anything behind metal-backed plasterboard, and a metal stud frame can confuse a cheap detector further. Find your stopcock now, usually under the kitchen sink, and check it turns freely so you can shut off the water fast if you hit a pipe. If you have any doubt at all, isolate the relevant circuit at the consumer unit before drilling, and turn the water off at the stopcock before cutting into anything that could carry water.