Life would be really easy for the do-it-yourselfer if solid wood were behind all the drywall in your house. Then every time you needed to install a shelf or hang something heavy, you could just drive in a screw and be done with it.
Alas, that’s not the case, and so instead we have a group of fasteners that are lumped together under the general heading of "drywall anchors." Drywall anchors are designed to be installed into the drywall where there’s no wood, and give you a solid place to attach whatever it is you’re looking to hang.
If you’ve looked on the shelf in your local home center or hardware store, you’ve no doubt noticed there are many different drywall anchors to choose from. Let’s try to clear up a little bit of the confusion.
Plastic anchors are some of the most common of the drywall anchors, and are the ones you’ll often find included free with the hardware packet in different home improvement items you buy. Plastic anchors are also the lightest-duty drywall anchors.
To use the anchor, you first need to drill a pilot hole in the drywall. It’s important that the hole be the correct diameter for the anchor being used, because if it’s too large, the anchor will rotate in the hole and won’t grip correctly, and if it’s too small, it’ll distort as you drive it into place. The pilot-hole diameter should be listed on the packaging.
After drilling the hole, tap the anchor into place until the anchor’s shoulder is flat against the wall. Ribs on the outside of the anchor grip the drywall, and hold the anchor in place.
A screw that’s matched to the anchor in diameter and length is driven into the anchor to expand it inside the hole, locking it in place. Once the anchor is locked, the screw can be removed and reused, and the anchor will remain in place.
Plastic wall anchors are sized according to the length and diameter of the matching screw, so select one based on how big a screw you need for what you’re hanging.
Hollow wall anchors
For medium-duty use, there are the hollow wall anchors, also commonly known as "molly bolts." Some types require that a pilot hole be drilled in the drywall first, while others have a pointed end and can be driven into the drywall with a hammer.
With either type, once the anchor has been inserted or driven into the wall, the preinstalled screw is tightened. Tightening the screw pulls the end of the anchor forward, toward the back side of the drywall. As it does, the metal sides of the anchor distort into a mushroom shape, locking the anchor against the wall.
Once the anchor is locked, you can remove the screw from the anchor, insert it through whatever it is you want to hang, then reinstall the screw into the anchor. Screws can be removed and reinstalled with this type of anchor.
Hollow wall anchors are sized for the thickness of the material they’ll be installed in, and the length of the screw. They’re available for 1/2-inch-thick and 5/8-inch-thick drywall, as well as thinner materials such as hollow doors.
Drive anchors are very easy to use, and offer both medium- and heavy-duty applications in both plastic and metal varieties. Both types are self-drilling and don’t require a pilot hole — they’re installed by simply screwing them into the drywall with a screw gun. Both types have wide screw threads that cut and grip into the drywall. After the anchor itself is installed in the wall, a screw is driven into it to expand the anchor, locking it in place. The screw can then be removed and reused.
Drive anchors are typically available in only one screw diameter, but can be used with different screw lengths.
A toggle bolt is a long machine-threaded screw with a pair of spring-loaded metal wings at the end. First, drill a pilot hole of the correct diameter. Insert the toggle bolt through the object you wish to attach, then compress the wings and push them into the hole in the wall.
Push the screw into the wall until the wings pop open again inside the wall. Pull back on the screw so the wings are in contact with the back of the wall, and tighten the screw. Toggle bolts work well for heavier installations, but if you remove the screw, the toggle wings inside the wall are lost.
Toggle bolts are sized by the diameter and length of the screw, depending on the thickness of the wall and the thickness of the object you’re attaching.
Another type of toggle bolt is called the SnapToggle. It works in a similar fashion, but has a different design that allows the wing to remain in place if the bolt is removed. SnapToggles are a little more expensive than conventional toggle bolts, but are faster and easier to install, and are a better choice if you intend to remove the item being fastened.
Drywall anchors are available at home centers, hardware stores, lumberyards, and many other retailers. Be sure to follow the manufacturer’s specific instructions for installation and load ratings.