Wall plugs prevent screws from slipping out of a masonry wall. When you plug a screw hole, you will need to make sure that the plug is the appropriate length and diameter for the screws you are using.
Another factor to consider when buying plugs is how heavy the load being placed on the fittings will be. If you are nailing battens or fixing lightweight objects such as picture frames to a masonry wall, you may not need a wall plug as masonry nails will have sufficient gripping power.
There is a wide selection of wall plugs available; the most widely used are described below:
Common wall plug
Manufactured from plastic and designed for fixing screws into masonry walls, the common wall plug is available in a range of lengths and diameters.
Frame fixing
A long plastic plug supplied with the appropriate sized screw, the frame fixing is most commonly used for fixing window and doorframes to masonry walls. With the window or doorframe in position, the frame fixing is tapped into the pre-drilled holes and tightened with a screwdriver.
Hammer fixing
Very similar to the frame fixing but hammered into position until a final half turn tightens it securely.
Metal expansion bolts
A metal expansion bolt comprises of a screw fixing with a bolt head inserted into a metal sleeve. Metal expansion bolts are used for fixing heavy objects to walls or supports that need to bear heavy objects. As the bolt is screwed in place the metal sleeve expands inside the hole producing an extremely strong fix.
Fixings for hollow cavity walls
Hollow cavity walls will require a different type of plug. There is a wide selection available but it is important to remember that none of these cavity wall fixings are suitable for heavy loads.
Cavity wall plugs
Cavity wall plugs look similar to the common wall plug but taper towards the end. The plastic plug is pushed into the drilled hole and when the screw is tightened the end of the wall plug opens out producing a tight fixing.
Self-drilling cavity wall plug
This is a tapered plug with a screw thread on the outside of the barrel which allows the plug to be screwed into a hole drilled in the wall. The screw is then inserted into the plug and tightened in the normal way.
Hollow-wall anchor
This is a metal combination fixing. The screw has a metal sleeve which is inserted into the drilled hole. As the screw is tightened it pulls up the body of the anchor and grips the back of the plasterboard.
Spring toggle
A metal fixing comprising of a bolt with two spring-loaded arms that open out when clear of the hole. As the bolt is tightened the arms grip the wall.
Gravity toggle
Similar to a spring toggle but with only one arm at the end of the bolt which drops with gravity once it is clear of the hole. As the bolt is tightened the arm will grip the plasterboard producing a secure fixing that is suitable for heavier loads.