DS-02Work out what's behind the plasterLath and plaster is thin timber laths nailed to timber studs, with lime plaster keyed through the gaps — there's no plasterboard or dot-and-dab behind it. Use a stud detector or a strong magnet to find the line of old cut nails, and knock along the wall: a duller, firmer sound means a stud, a hollow sound means you're between them. Some older houses have lath and plaster fixed over timber battens on solid brick instead — a dead, solid knock suggests masonry close behind rather than a stud. If a small test hole brings out fine grey swarf instead of wood dust, someone has fitted a metal stud behind a plaster skim, and you'll need a proper metal-stud fixing rather than a wood screw.