BS-05Secure a bath that moves (skip if it doesn't rock)If the bath rocked in Step 1, sealant will keep splitting until it's held still. Baths are normally screwed to the wall through a lip or bracket, so find where that fixing has failed. Before drilling, remember cables and pipes can run almost anywhere near a bathroom — a detector helps but can miss deep cables, metal conduit, or pipework, so drill carefully and be ready to stop. Find your stopcock (usually under the kitchen sink) and check it turns before you start, isolate the circuit at the consumer unit if there's any doubt, and turn the water off before cutting into anything that could carry water. Work out the wall type first: tap the wall — a dull thud between studs and a sharper knock on the stud itself — and run a stud detector or magnet along a line of screw heads to find timber studs at roughly 400mm or 600mm centres. A small pilot hole bringing out pale dust means timber; bright metal swarf means a metal stud. On solid brick or block, drill 6mm and use a wall plug with a 5x50mm screw, about 50mm deep. Into a timber stud, drive a wood screw straight into its centre. Into a metal stud, use a self-drilling metal-stud fixing or a hollow-wall toggle rated for metal — never a plastic plug or an ordinary wood screw, as both strip straight through 0.5mm steel. Into plasterboard between studs, use a toggle or hollow-wall anchor rated for the bracket's pull, not a lightweight picture-hook fixing. Through dot-and-dab plasterboard, use a fixing long enough (typically 75-90mm) to bite into the masonry behind, not just the dab. Into lath and plaster, find the timber lath by feeling for solid resistance and screw into that, not just the plaster skim. If the fixing point lands between studs with nothing solid behind it, fit a timber noggin (50x25mm) between the studs first and screw into that instead.