Why plaster is different
Most Ontario heritage homes (pre-1950) have plaster over wood lath, not drywall. Plaster is harder than drywall but far more brittle. Standard plastic wall plugs designed for drywall will crack the plaster around them as they expand, and the mirror will eventually fall.
The right anchor for plaster
Use one of these:
- Metal toggle bolt (3/16″ or larger) — safe up to 55 lb.
- Metal expansion anchor rated for plaster/lath — expands into a wood lath strip behind the plaster.
- Wood screws into lath — if you can find a lath strip, driving a 2″ #10 wood screw straight into it is stronger than any anchor.
Step-by-step
- Use a stud finder to check for wood lath backing.
- Mark the hole locations with painter's tape.
- Drill a small pilot hole (1/8″) — if the drill bit passes through very easily then hits resistance, you've found a lath strip.
- For toggle bolts, drill 3/8″ hole; for expansion anchors, follow the anchor's specific instructions.
- Insert the anchor. Fold toggle bolts before inserting; expansion anchors get tapped in flush.
- Hang the mirror. Level. Step back and confirm from across the room.
Mistakes to avoid
- Never use plastic wall plugs in plaster. They crumble the plaster and fail within months.
- Don't drill without pilot holes. Plaster cracks around large drill bits used without a pilot.
- Don't overtighten. Snug the screw against the D-ring and stop. Overtightening pulls the anchor through the plaster.
Not sure about your wall? Send a photo to salkaladecor@gmail.com and our team will recommend the exact hardware.
