PL-03Confirm the joist and check for cables and pipesBefore you drill anything, find your stopcock (usually under the kitchen sink) and check it turns freely, so you can shut the water off fast if you ever hit a pipe. A detector can miss cables or pipes, especially near a ceiling rose, so if there's any doubt at all, isolate the relevant circuit at the consumer unit before drilling. Drill a small pilot hole at your marked spot: fine timber dust means you've found the joist, but crumbly white or grey dust means you're still in the plaster and laths and need to shift your hole slightly.