· Michael Blair
Almost every fallen shelf, mirror or television was fixed with an anchor that was never rated for it. What holds depends on the wall, the load and whether the load is pulling out or hanging down.
Find a stud where you can
Nothing beats a screw into framing. For anything heavy — televisions, cabinets, floating shelves with real weight — the fixing should reach a stud, and a magnetic finder locating drywall screws is more reliable than an electronic one on old walls.
Studs are commonly at 16 inch centres, occasionally 24 in newer construction.
Anchors by holding power
Plastic expansion plugs hold very little and are what most failures used. Self-drilling threaded anchors hold moderate loads. Toggle bolts and strap toggles hold the most in drywall.
Ratings assume a single anchor in sound drywall — spread a heavy load across several rather than trusting one.
- Anything heavy: fix into a stud
- Light picture: plastic plug or a picture hook is fine
- Moderate load: self-drilling threaded anchor
- Heavy load off-stud: toggle or strap toggle
- Plaster and lath: pre-drill, never hammer
Plaster is different
Nashville’s older housing is plaster over lath, which is brittle and cracks if you hammer or over-tighten. Always pre-drill, use a slow speed, and prefer toggles over expansion anchors.
Hitting a lath gives good purchase; hitting the gap between does not, so it is worth locating one.
Tile and masonry
Drill tile with a carbide or diamond bit at low speed with no hammer action, starting through masking tape so the bit does not wander. Then switch to hammer mode once through the tile if there is masonry behind.
Aim for the grout line where you can — easier to drill and far easier to repair later.