PR-04Check for cables and pipes before you drillRun a cable and pipe detector over your marked line, but still assume something could be there even if it shows clear — detectors miss cables that are deep, in metal conduit, behind metal-backed plasterboard, or outside the normal safe zones. Find your stopcock now (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 at all, 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.