clock menu more-arrow no yes

Filed under:


The most common household fastener is the nail. Nails are good for joining wood together because the fibers grip and hold the nail. Nails are not effective in materials like wallboard, plaster or masonry because these materials offer little or no gripping power.

Fortunately, specialty fasteners are available that are designed for such applications. There are fasteners designed for hollow walls; they grip the plasterboard by expanding in, or behind, the wall and remain securely in place. For plaster, concrete or masonry, there are expansion anchors that widen to grip the surrounding material.A well-stocked hardware store or home center will carry a wide selection of these fasteners. When purchasing any fastener, be sure to read the manufacturers' specifications on the label. These specifications will usually list the load capacity of the fastener. They will, for example, state whether the device is suitable for light, medium or heavy loads. In general, light loads are those up to 400 pounds. Medium loads are between 400 and 4,000 pounds. Heavy loads are above 4,000 points.

Bear in mind, however, that these load ratings are only for the fastener; they do not take into consideration the structural integrity of the supporting wall.

Almost all specialty fasteners must be inserted into a hole drilled into the supporting material. Usually the specifications on the package will indicate the hole diameter required. If you're working with plaster board, you can drill holes with a high speed drill bit. Plaster, concrete or masonry will quickly dull an ordinary drill bit. For these , it's best to use a carbide-tipped bit.

Carbide-tipped masonry bits are available in diameters up to 1/2 inch. If possible, use a variable-speed drill and run the drill at a slow speed (about 500 RPM). This will keep the bit from overheating. For larger holes, it's easier to drill the hole with a smaller bit (about 1/4 inch) then enlarge it with a larger bit.

If you have to drill a number of holes in hard concrete, you can rent a hammer drill for about $10 per day (rental costs may vary from store to store). This tool uses a special percussion masonry drill bit that can bore a hole in few seconds. Make sure that you ask the dealer for a demonstration before you operate the tool, and be sure to wear proper safety gear.

While there are a number of new hollow-wall fasteners available, the most popular are still toggle bolts, hollow-wall expansion anchors and plastic anchors. A toggle bolt consists of a pair of spring-loaded wings threaded onto a long bolt. To use the toggle bolt, squeeze the wing section together against the bolt and push it through the hole you've drilled in the wall. The wings will expand to grip the opposite side of the wall.

When the bolt is withdrawn from the assembly, the wing section will disengage and drop behind the wall. If you are mounting a fixture on the wall, it must be installed on the bolt and held in place while the toggle bolt is tightened. This is no problem for a lightweight hook or shelf bracket, but it can be difficult if you're mounting a heavy fixture. Here it may be easier to use an expansion anchor.

The expansion anchor is inserted into a hole drilled in the wall. When the companion bolt is threaded in the anchor, the anchor expands and grips the wall. The bolt can be removed without dislodging the anchor. This feature makes it easy to install a cumbersome fixture by first securing the anchor in place, then attaching the fixture with the bolt.

Plastic anchors are another type of expansion plug. Tap one into a 1/4-inch hole and drive a screw into the plug center; it will expand to grip the wall. These are relatively cheap anchors and are suitable for light duty applications.

Another type of hollow-wall anchor combines the advantages of the toggle bolt and the expansion anchor. It's made of plastic and has wings like the toggle bolt. Squeeze the wings together and push the anchor into the drilled hole. The wings will expand on the other side of the wall.

Because concrete walls are thick, masonry fasteners can only grip from within; they cannot fasten to the opposite side of the wall. For light loads, there are plastic anchors and metal shields. They are made of either soft plastic or metal that expands while gripping screw threads. These fasteners are good in soft masonry like mortar joints because they will not expand enough to crack the material.

For medium duty, there are sleeve anchors that expand when an internal bolt wedges the expansion sleeve against the side of the hole. Masonry screws are also available. These are special hardened screws that cut threads into the masonry. You must drill a pilot hole first, then drive the screw with either a Phillips-head screwdriver or a hex-head nut driver - they can be difficult to drive in hard concrete.

For heavy-duty applications, there are heavy duty sleeve anchors and wedge anchors. Wedge anchors have a steel collar around the bolt and a wedge at the end of the bolt. As the bolt is tightened, the wedge forces the collar apart, locking it against the surrounding material. These anchors are difficult to remove once they are installed.