TN-03Re-fix any loose board and drill safelyCables and pipes can run almost anywhere near a bathroom wall — a detector helps but can miss deep cables, metal conduit or anything behind metal-backed board, so still treat every hole as if something could be there. Find your stopcock (usually under the kitchen sink) and check it turns before you start. If in doubt, isolate the circuit at the consumer unit before drilling, and turn off the water at the stopcock before drilling near any pipe run. Drill a small pilot hole first: fine pale dust means timber stud, grey powder means masonry or dot-and-dab, and bright metal swarf means a metal stud. Fix into a timber stud with a 40mm wood screw driven into its centre; for a metal stud use a self-drilling metal-stud screw or snap-toggle fixing, never a wood screw or plastic plug, which strip straight through 0.5mm steel. Into solid masonry behind the board, drill to the plug's stated depth and fit a plug and screw rated for the load. Behind dot-and-dab, use a fixing long enough to pass through the board, the adhesive dabs and still bite at least 25mm into the masonry, typically 60-75mm overall.