BP-04Work out what's behind the wall before drillingIf the panel needs a support batten fixed to the wall, sweep a stud detector or magnet along the wall to find a vertical line of screw heads — that's a stud, and a hollow sound between them confirms the spacing. A small pilot hole showing timber dust means a timber stud; fine grey swarf means a metal stud, common in flats and newer builds. Cables and pipes can run almost anywhere, so use a detector but still treat the wall as live until proven otherwise, and check your stopcock (usually under the kitchen sink) turns before you start. If you have any doubt at all, isolate the circuit at the consumer unit before drilling.