PS-02Work out exactly what you're fixing intoRun a stud detector or magnet along the wall at bracket height to find the studs and confirm their spacing, usually 400mm or 600mm apart. Tap the wall: a dull thud is solid masonry, a hollow drum sound is plasterboard on studs or a dot-and-dab wall. Drill a small 3mm pilot hole where a fixing will go — fine timber dust means a timber stud, grey powder means brick or block, and bright metal swarf means a metal stud. If the wall sounds hollow everywhere with no solid stud line, and the plaster feels slightly springy with fine horizontal ridges under the surface, you likely have lath and plaster — old timber laths under lime plaster, common in pre-1930s homes, and it crumbles easily around fixings.