SR-03Check for cables and pipes, and know your isolation pointsBathrooms often have cables for lighting, extractor fans or shaver sockets, and pipes for the shower and basin. Run a detector over every marked point, but still treat the wall as if something is there — detectors miss cables in metal conduit, behind metal-backed board, or deeper than expected. Find your stopcock now, usually under the kitchen sink, and check it turns. If you have any doubt about what's behind a mark, isolate the relevant circuit at the consumer unit before drilling, and turn off the water at the stopcock before drilling anywhere near a shower or basin pipe run.