AS-05Drill and fix the side battensCables and pipes can run almost anywhere in a wall, not just in obvious zones. Use a detector, but still treat the wall as live until proven otherwise: find your stopcock (usually under the kitchen sink) and check it turns before you start, so you can shut off water fast if you hit a pipe. If you have any doubt, isolate the relevant circuit at the consumer unit before drilling. For solid brick or block, drill with a 7mm masonry bit to 45mm depth, insert a wall plug, and drive a 50mm screw. For plasterboard on timber studs, find the stud centre and use a 50-60mm wood screw straight into the timber — no plug needed. For plasterboard on metal studs, never use a wood screw or plastic plug, as it strips straight through 0.5mm steel; use a self-drilling metal-stud screw or a toggle-type hollow-wall anchor rated for the shelf's load. For dot-and-dab walls, use a fixing long enough to pass through the plasterboard, the dab void and into the masonry behind — typically 60-75mm — or a plasterboard toggle rated for light loads if you can't reach the masonry. For lath and plaster, locate the timber studs behind the laths with your detector and fix into them with a 50mm screw; don't rely on the plaster alone, as it's brittle and will crack.