MW-04Check for hidden pipes and cables before you drillCables and pipes can run almost anywhere in a wall, not just in neat vertical or horizontal lines. Run a cable and pipe detector over your marked spots, but treat it as a warning, not a guarantee — detectors 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 about what's behind the wall, isolate the relevant circuit at the consumer unit first.