AR-06Fix the two leg pieces — method depends on the wallPin each leg into the door lining every 300-400mm — this is your main fixing on every wall type. Where the outer edge of the architrave sits on the wall itself, the fixing changes: on a timber stud wall, nail into the stud or noggin where you find one; on a metal stud wall, do not nail or screw into the bare steel, as an ordinary nail or wood screw pulls straight through — rely on the pins into the lining and add panel adhesive along the back for extra grip. On solid brick or block, nailing is hard work and often splits the trim, so use grab adhesive along the back instead of nails. On dot-and-dab plasterboard, nails alone will not hold, so use adhesive plus pins into the lining; if you need a stronger fix, a fixing long enough to reach the masonry behind the dabs will hold better than anything in the board alone. On lath and plaster, use fewer pins than you think you need and go gently — the lath cracks easily — and back the trim up with adhesive rather than relying on nails.