HR-04Check for hidden pipes and cables before drillingCables and pipes can run almost anywhere, including up exterior walls to outdoor lights, sockets or an outside tap. Run a detector over each marked point, 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 off the water 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, and turn off the water at the stopcock before drilling near any known pipe run.