CT-04Safety check before you drillCables and pipes can run almost anywhere, not just in the marked safe zones, and a detector can miss cables that are deep, boxed in metal conduit, or hidden behind metal-backed plasterboard. Run the detector over every mark, then still treat each hole as if something could be there. Find your stopcock now (usually under the kitchen sink) and check it turns freely, so you can shut the water off fast if you ever hit a pipe. If you have any doubt at all about what's behind the wall, isolate the relevant circuit at the consumer unit before you drill.