How to put up shelves securely: wall types, fixings and wall plugs explained

Find out what kind of wall you have

• Solid masonry (brick, block, concrete): sounds dull and solid. Drilling produces red, grey or white dust. Common for external walls and many older internal walls.
• Plasterboard (drywall) on a frame: sounds hollow, with a firmer sound over the studs. Drilling produces white powder, then the bit breaks through into empty space.
• Timber studs: the vertical wooden frame behind plasterboard, usually at regular intervals. A stud finder, a small magnet that sticks to the screw heads, or tapping and listening will locate them.
• Lath and plaster in older houses: hard plaster over thin wooden strips. Treat it carefully; it can crumble and is best fixed into the studs behind it.

Check for cables and pipes first

• Use a cable and pipe detector before drilling, and scan in more than one direction.
• In the UK, wiring regulations generally expect hidden cables in walls to run in "safe zones": horizontally or vertically in line with sockets, switches and other electrical fittings, and within a band near the ceiling and near internal corners. Do not drill directly above, below or beside a socket or switch, or close to a ceiling or corner. Not every installation follows the rules, so treat this as a warning map, not a guarantee.
• Pipes often run vertically from radiators, boilers, sinks and toilets, and horizontally just above the floor.
• If in doubt, move the shelf.

Choosing fixings

• Masonry: drill with a masonry bit (and hammer action for brick or concrete) and use plastic wall plugs sized to match the screw and the drill bit. The plug packaging says which drill size and screw gauge it takes. Heavy loads may need longer screws or frame fixings.
• Timber studs: wood screws straight into the stud are among the strongest fixings you can get. Aim for the centre of the stud and drill a pilot hole.
• Plasterboard between studs: use a cavity fixing. Options include metal cavity anchors (often called hollow wall anchors), which expand behind the board, spring or gravity toggles, which flip open behind it, and self-drilling plasterboard plugs for light loads. Each has a stated load limit on the packet, which assumes good board and correct fitting.
• Avoid ordinary plastic plugs in plasterboard; they spin and pull out.

Load limits

• The weakest link sets the limit: the fixings, the brackets, the shelf material and the wall itself.
• Check the rating of each fixing and bracket, and remember that the weight of books and the leverage of a deep shelf put more strain on the top screws than the figure on the pack suggests.
• Plan for what will really go on the shelf. Books, crockery and plants are much heavier than they look.
• For heavy loads on plasterboard, fix into studs, or fit a timber batten across several studs and attach the brackets to that.
• Floating shelves rely heavily on their fixing and are less forgiving than brackets.

Putting it up

1. Hold the shelf in place, mark the position and draw a level line with a spirit level or a laser level.
2. Mark the bracket holes on the line, scan once more for cables and pipes, then drill.
3. For masonry, vacuum or blow the dust out of each hole so the plug grips.
4. Push the plugs in until flush, fix the first bracket loosely, check level, then fix the rest.
5. Check level again with the shelf in place before tightening fully.
6. Load the shelf gradually and look for any movement or cracking around the fixings.