How to hang a big, heavy mirror

Materials needed

• D-rings or mirror clips — top and bottom for very heavy frames
• Heavy-duty picture wire OR (recommended for over 15kg) a French cleat
• Spring-toggle bolts for plasterboard, M6 masonry plugs for brick
• Felt or rubber bumpers for the bottom edge so the mirror sits flush and protects the wall

Tools required

• Cordless drill with masonry & wood bits
• Spirit level — minimum 60cm so it spans the full mirror width
• Stud / cable detector
• Tape measure, pencil, sturdy step ladder
• A second pair of hands — non-negotiable above 10kg

Step-by-step (French cleat method)

1. Weigh the mirror. Bathroom scales work fine. Match anchors to that weight times a x2 safety factor.
2. Decide the centre height. Eye level for an entryway, ~145cm to centre for a feature wall, 15–20cm above a sofa back for a living room.
3. Fix one half of the cleat to the wall using two anchors into stud or masonry. Level it.
4. Fix the matching half to the back of the mirror, parallel and at the same width apart as the wall piece.
5. Lift the mirror, hook the cleat, slide level. Bumpers go on the bottom corners to stop it kicking out.
6. Tug-test gently. Re-check level after 48 hours — some settling is normal.

What I see go wrong

• A single picture-hook on plasterboard holding a 25kg mirror — eventually pulls through. Always.
• Wire across the back too tight — it pulls the frame apart over time, especially on cheap MDF backs.
• Hung over a radiator — heat warps the silvering. Leave at least 20cm clearance.
• Single anchor on plasterboard for a heavy frame — use two, spaced apart, every time.

When to call a pro

Anything over 15kg, mirrors wider than a metre, anything mounted above a bath or sink (where it can fall on plumbing), or old London walls where you're not sure what's behind the plaster — those are the jobs where the right anchor choice and a proper level make a big difference.