Install or remove wall anchors
Some materials, such as plasterboard (wallboard) or concrete, crumble when drilled. Some materials aren’t strong enough to hold a heavy object attached to them.
So if, for example, you want to attach a picture frame to a wall in a position where you can’t line it up with a stud or solid piece of timber behind the wall, you’ll need an anchor or toggle to strengthen the attachment. Anchors are useful on hollow surfaces such as doors, walls and ceilings where there is no convenient stud behind the surface. They are also useful on extremely hard surfaces such as concrete.
There is a wide range of anchor fasteners and you will need to find the one that would be most suitable for the job you have in hand. Each anchor will have a size and weight rating. Choose the type you need by reading Which anchor do I choose?
Once you have decided on the anchor you need use the following information to
Plastic expansion anchors
These are designed for light weights only. Unfortunately, sometimes, manufacturers include them in packs for installing items such as towel rails or soap racks or small cabinets. They aren’t strong enough for any situation where long-term pulling or pushing is involved, or for attaching shelves or cabinets where the weight tends to pull the anchor outwards. They are, however, quite adequate for anything where the force is constant and downward against the wall, e.g. for hanging paintings or mirrors.
Expansion anchors are only as strong as the material they are installed in.
They work by expanding when a screw or bolt is threaded into them. They are
colour-coded according to their size and each one suits a certain screw size. Just check the packet.
First make a hole for the anchor in the surface. The size of hole will be given on the packaging. If you’re buying only one anchor and screw from a box at the hardware store, make sure you note the hole size before you leave the shop.
It is best if the hole size is slightly smaller than the maximum width of the anchor below the rim. Press or tap the anchor into the hole until it is flush with the surface. If the hole is too small the anchor will collapse as you tap it in!
If you intend to hang something from the screw, screw it into the anchor most of the way. If you’re attaching something flush to the wall, pass the screw through a hole in the object. Line it up with the anchor and screw it in and tighten.
Threaded plasterboard or drywall anchor
Punch or drill a starter hole the size of the point of the anchor to give yourself accurate positioning. Screw the anchor into the wall using a manual or power-drill Phillips head screwdriver until the anchor is flat against the wall. Don’t worry if the surface of the wall tears or buckles a little. This is quite normal, but obviously it is best to use these where your object is going to completely cover the anchor.
Insert the screw through the object and into the centre of the anchor and tighten, taking care not to overtighten, thus stripping the thread created in the plaster.
Remove a threaded wall anchor
Insert a screwdriver into the head of the anchor and turn anticlockwise.
Winged plastic anchors
Winged or sleeve anchors are stronger than expansion anchors because they key in behind a hollow wall as well as through it.
Drill a hole of an appropriate size (slightly smaller than the top of the anchor just below the flange). Close the anchor by pressing the wings towards each other and push the anchor through the wall. A special tool is provided with the anchor, which pushes the centre of the wings out so they expand properly inside the hollow of the wall. The anchor won’t work properly if this isn’t done. If you don’t have the tool, a small screwdriver inserted into the screw hole will do the same job.
Pass the screw through a hole in the object you’re attaching and screw it into the anchor, which, when tightened, pulls the wings against the back of the wall.
Remove a winged plastic anchor
Turn a screw clockwise into the head of the anchor and pull. If it doesn’t come free, you’ll have to drill the head of the anchor out using a 7-mm bit. The body of the anchor will drop into the wall cavity.
Sleeve-type anchors or molly bolts
Drill a hole into the wall the same diameter as the molly. Tap the molly in until the head is flush with the wall. Now turn the molly’s screw clockwise. Inside the wall, the screw will pull the base of the molly towards the inside of the wall and expand the metal legs against the back of the wall . Stop screwing when the molly has pulled tight against your side of the wall and you feel strong resistance.
Now the molly is installed and you can unscrew the screw to attach an object. You can also replace the object, because the molly creates a permanent thread in the wall.
Remove a molly bolt
Mollies are designed to stay, so your only option is to place a too-large Phillips screwdriver on the head of the molly and hammer it gently through the plasterboard. You’ll then need to repair the hole (see ‘Repair a hole in a plasterboard wall’). If the molly is inserted into stronger material than plasterboard, you might try drilling the molly out with a sharp bit twice the size of the molly’s screw. Drill directly
into the molly hole. Press forward firmly and don’t swear when the molly starts to spin! Hopefully you’ll have drilled far enough so that a firm tap will break it and drop it into the wall cavity.