You can't drive screws directly into drywall and expect them to hold anything. Drywall is too loose and crumbly for that. You need wall anchors to support anything, and toggle anchors, also known as toggle bolts, are the strongest anchors there are.
A toggle bolt works by anchoring itself to the back of the drywall, so when you put outward force on the bolt, the entire sheet of drywall resists it, not just the crumbly core. The two types of toggle bolts are the wing style and the strap style, which features a solid support bar that makes it easier to install.
Toggle Bolts Are the Heavy-Duty Choice
The most secure way to drive a screw into drywall or plaster is to locate a wall stud using a stud finder or the old-fashioned tap-tap method and drive the screw into that. If the screw is long enough – a minimum of 2 inches – it won't go anywhere no matter what it supports. The problem with this method is that there isn't always a stud behind the spot in which you need the screw.
When there's no stud, you need a wall anchor. The choices, in order of increasing strength, include:
- conical plastic anchors
- self-drilling plastic screw anchors
- winged plastic anchors
- molly bolts
- toggle bolts
The weight a toggle bolt can support depends on the size of the bolt and the thickness of the drywall. The smallest toggle bolt with a 1/8-inch diameter can support 180 pounds of force in 3/8-inch drywall and 310 pounds in 3/4-inch drywall. A 1/2-inch diameter toggle bolt can support 340 pounds in 3/8-inch drywall and up to 600 pounds in 3/4-inch drywall.
Installation Starts with Drilling a Hole
When you purchase the toggle bolt you're going to install, check the packaging for the recommended hole size. If you're using traditional wing-style toggle bolts, fold the wings up against the shank and measure the width of the folded end. Use a drill bit with that diameter.
The important thing is to avoid making the hole larger than the flange at the head of the shank where you screw in the bolt. The flange has to rest against the surface of the drywall, or the bolt won't work.
Installing Wing-Style Toggle Bolts
Once you've made the hole, fold the wings together and push the shank, including the wings, through the hole. Insert the bolt into the shank after first inserting it through whatever you're going to hang.
The next step is a little tricky. Use your fingers or a screwdriver to hold the wings (which have spread out behind the drywall) against the back of the wall while you tighten the bolt with another screwdriver. If you don't maintain this tension, the shank will turn with the bolt. Once the bolt is reasonably tight, the shank won't turn, so you can release the tension and finish tightening the bolt.
Installing Strap-Style Toggle Anchors
Instead of wings, a strap toggle anchor has a spring-loaded bar, and it comes with a plastic frame. One popular brand, the Snaptoggle, gets its name from the method you use to install it as well as from the fact that it's a snap to install.
- Hold the bar perpendicular to the frame and slide it through the hole. The bar will automatically snap into position perpendicular to the wall.
- Slide the cap along the frame until it is flush against the wall, and then snap off the part of the frame that extends past the wall. Part of the frame stays inside the wall, holding the cap to the bar.
- Insert the bolt through the cap and screw it into the bar.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.