Hang an egg chair safely by fixing a spreader across several ceiling joists, never into lath and plaster alone.
EC-01Understand why lath and plaster can't take this loadAn egg chair with someone sitting in it can weigh 100-150kg, and it swings, which pulls sideways on the fixing as well as down. Lath and plaster is just old plaster keyed onto thin timber laths nailed to the joists — it has almost no strength of its own and will crumble under this kind of load. Every fixing must go into the solid timber joists above, spread across at least two of them, not into the plaster or a single lath.
EC-02Find your joists and check what's above the ceilingSweep the ceiling with your detector to find the line of joists — nail or screw heads usually run in a straight line roughly 400-600mm apart. Drill a small pilot hole where you plan to fix and check what comes out: fine pale dust means timber, and you're good to proceed. Older houses with lath and plaster almost always have timber joists, but if you find a thin metal channel or grid instead (some flats have been reboarded with a metal ceiling system), stop — these are not built to take a swinging load and you'll need a professional to specify a proper fixing.
EC-03Check for cables and pipes, and know how to shut things offCeiling voids can carry cables in almost any direction, and the timber laths and nails in an old ceiling can confuse a cheap detector, so treat every spot as live until you've proved otherwise. Find your stopcock now (usually under the kitchen sink) and check it turns freely, so you can shut water off fast if you ever hit a pipe. If there's any doubt — especially near a ceiling rose or light fitting — isolate that circuit at the consumer unit before you drill.
EC-04Fit a spreader from the loft, if you can get up thereThis is the strongest method. From the loft side, lay a timber noggin across at least two, ideally three, joists directly above where the chair will hang. Screw or coach-screw it down into each joist it crosses, then mark and drill a single hole down through the noggin and ceiling for your hook fixing.
1 each · Timber noggin, 47x100mm x 600mm (treated softwood)
EC-05No loft access? Spread the load from below insteadFix a timber spreader batten flat against the ceiling, running across at least two joists, using pilot holes and long wood screws driven through the lath and plaster into the solid centre of each joist — never into the plaster in between. This spreads the swing and sideways pull across more than one joist, which a single screw into one joist can't do safely.
EC-06Fit the heavy-duty ceiling hookDrill a clearance hole through the spreader (noggin or batten) and the ceiling below, sized for your coach bolt. Fit the hook or eye plate with a coach bolt, large washer and nut on the top side of the spreader, tightened fully. Use a fixing rated well above the combined weight of the chair and heaviest likely occupant — most egg chair hooks are rated to at least 150kg.
EC-07Make good the plaster around the fixingFill any gaps around the fixing hole with a flexible filler suited to old plaster, and let it cure fully before you paint or touch it. Don't rely on this filler for any strength — it's cosmetic only, the fixing does all the work.
EC-08Load-test the fixing before you trust itHang a weight roughly equal to your heaviest expected occupant from the hook and leave it for a few hours, checking for any movement, cracking or dropping. Give the weight a firm sideways pull and swing to mimic getting in and out of the chair. Only move on once you're confident nothing has shifted.
EC-09Hang the chair and check clearanceAttach the chair's rope or chain to the hook using a rated shackle or carabiner if one isn't already supplied. Check the chair swings freely without hitting walls, furniture or light fittings, and sit in it gently the first time rather than dropping into it.
EC-10Tidy up and recheck after a weekVacuum plaster dust from the floor and any dust sheets, and bag up rubble for disposal. After a week of normal use, look up and check the fixing, spreader and surrounding plaster again for any signs of movement or cracking, and recheck every few months after that.