MH-03Check for cables and pipes, and know your shut-offsCables and pipes can run almost anywhere behind a wall, not just in the usual safe zones, so use a detector but still assume something could be there until you've proved otherwise. Detectors miss cables that are deep, run in metal conduit, sit behind metal-backed plasterboard, or get confused by a metal stud frame, so drill slowly and stop at any sign of resistance, heat, or a colour change in the dust. Before you drill, find your stopcock (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 off the water at the stopcock before cutting into anything that could carry water.