The right fixing depends almost entirely on what the wall is made of: solid masonry needs a wall plug and screw or a masonry anchor, while hollow plasterboard needs a fixing that grips the back of the board rather than the air behind it. Match the anchor to the wall and to the weight it must hold, and shelves and pictures stay put; get either wrong and the fixing pulls out.
Choosing the right fixing for the wall you have
Before buying anything, work out what you are drilling into. A quick tap tells you a lot: a solid, dull thud usually means brick or block behind plaster, while a light, hollow sound means plasterboard with a cavity behind it. A small drill test or a sharp bradawl will confirm it.
Once you know the wall type, the choice narrows quickly. The other factor is load. A framed photo weighs little; a heavy mirror, a full bookshelf or a wall-mounted television can put several kilograms of pull on each fixing, and the leverage on a deep shelf multiplies that strain.
- Solid walls (brick, block, concrete): a plastic wall plug with a wood screw for light to medium loads; a frame fixing or expansion bolt for heavy items.
- Plasterboard with a cavity behind: a plasterboard fixing such as a spring toggle, metal self-drill anchor or expanding nylon plug.
- Stud walls: screw directly into the timber stud wherever possible, as that is far stronger than any cavity fixing.
If a fixing pack lists a maximum weight, treat it as a guide for ideal conditions, not a promise. Older plaster, crumbling mortar and damp can all reduce holding power, so a sensible margin is wise.
Plasterboard, masonry and stud walls compared
Match the anchor to the wall and to the weight it must hold, and shelves and pictures stay put; get either wrong and the fixing pulls out.
Masonry is the most forgiving for heavy loads. A correctly sized hole, the matching plug pushed flush, and a screw driven home gives a strong, reliable hold. The main risks are drilling too large a hole or hitting soft, perished mortar in an old wall.
Plasterboard is the trickiest. The board itself is only around 9.5mm or 12.5mm thick and is easily crushed, so the fixing has to spread its grip across the back face. Spring toggles and metal self-drill anchors (sometimes called "self-tappers") cope with more weight than basic plastic plugs, but no plasterboard fixing on its own should carry a heavy load such as a bracket holding a long shelf.
Stud walls combine the two. Behind the plasterboard sit vertical timber studs, usually spaced at 400mm or 600mm centres. A stud detector — an inexpensive electronic gadget that beeps over solid timber — lets you screw straight into the wood, which is the strongest fixing a hollow wall offers. Between the studs you are back to relying on plasterboard anchors.
One safety point worth repeating: electrical cables and pipes often run vertically above and below sockets and switches, and horizontally near ceilings and skirting. A combined detector that finds metal and live wires is a cheap way to avoid drilling into something dangerous.
Hanging pictures and mirrors so they stay put
For lighter frames, the load is usually modest enough that the wall type matters less than the hook. A single picture hook with a hardened pin works in plaster over brick for most framed prints. Heavier frames are better hung from two points, spread apart, which keeps them level and shares the weight.
Mirrors are a different matter because glass adds significant weight. A large mirror should be fixed into masonry with plugs and screws, or into studs on a stud wall, never on a single plasterboard anchor alone. Where the mirror has its own fixing plates or D-rings, line them up, mark through them, and check the marks are level before drilling.
A few habits make the job cleaner:
- Measure from the floor or ceiling to a consistent point so a row of frames aligns.
- Use a spirit level, or a level app, on the hanging wire or bracket rather than the frame edge.
- Mark the drill point with a cross and a pencil, then check it twice before the drill goes in.
- For anything heavy, two fixings spaced apart resist tilting far better than one central hook.
Mounting plates with a sawtooth or keyhole slot are common on mirrors and clocks. They are forgiving for hanging but can slip sideways, so a second small fixing or a dab of removable adhesive pad steadies them.
Fitting floating and bracket shelves level
Shelves carry sustained weight and leverage, so the fixing matters more than for a picture. Bracket shelves are the more honest design: visible L-brackets carry the load to the wall, and you can see exactly what is holding the shelf up. Floating shelves hide their support inside the shelf, which looks neat but puts heavy demands on a small number of concealed fixings.
Floating shelves rely on a hidden bracket or steel rod that the shelf slides onto. Because all the load passes through a few points, these are best fixed into masonry or into studs. On plain plasterboard a floating shelf should carry only very light items, and even then the strongest available cavity fixings are needed.
To fit any shelf level, mark the first fixing point, then use a spirit level to mark the others along a horizontal line. For a run of shelves, a faint pencil line drawn with the level acts as a guide. Drill, fix the bracket or rail, and check it sits true before loading anything onto it.
A common mistake is loading the shelf to its limit straight away. It is sensible to add weight gradually and watch for any sag, movement or cracking around the fixings in the first few days. If a fixing shows signs of pulling, it is far easier to add support before the shelf is full than after something has fallen.
When in doubt about a heavy load or an awkward wall, a qualified tradesperson can confirm the wall construction and recommend a fixing rated for the weight. Knowing what your wall is made of, and matching the anchor to it, resolves most of the uncertainty before any hole is drilled.
Updated: June 2026