CT-03Check for pipes and cables, and know how to shut things offCables and pipes can run almost anywhere above a ceiling, including lighting circuits and pipework serving a flat above. Use a detector, but still assume something's there and drill carefully — detectors miss cables that are deep, in metal conduit, or behind metal-backed board, and a metal furring channel confuses cheap detectors further. Before drilling, find your stopcock (usually under the kitchen sink) and check it turns freely. If you have any doubt, 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.