KR-02Work out what's behind the wallKitchen walls hide different things behind tiles: solid brick or block, plasterboard on timber studs, plasterboard on metal studs, dot-and-dab plasterboard on masonry, or in an older house, lath and plaster. Run a detector or magnet along the wall looking for a line of screw heads, and tap to feel for a hollow sound between studs. A small 2mm pilot hole tells you more: pale wood dust means a timber stud or lath, fine grey metal swarf means a metal stud, and solid resistance with brick dust means masonry.