TV-04Check for hidden pipes and cables, and know how to shut things offCables and pipes can run almost anywhere in a wall, not just in neat vertical or horizontal lines. Run a cable and pipe detector over the marked spots, but still treat the wall as if something's there — detectors can miss cables that are deep, in metal conduit, or outside the usual safe zones. 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 at all, isolate the relevant circuit at the consumer unit before drilling.