Attaching a hose reel or a pair of shelf brackets to a wood surface is a fairly uncomplicated project. Try the same job on concrete, brick or stone, and it quickly becomes real work. Although there are special fasteners designed for these jobs, it’s easy to get confused about which to choose and how to install them so they’ll never budge.
Here, we show you the tools and techniques you need to work with masonry. We sort through the fasteners, pointing out which are best for the jobs most of us do once in a while, like attaching shelves to a concrete wall or hanging a trellis on brick.
Masonry anchors look different from one another, but they are alike in one respect: You’ll need to drill a hole in the base material. Often, the depth and diameter of the hole are crucial to the holding ability of the anchor. So you should always follow manufacturer’s instructions on hole depth and diameter carefully.
If you have only a few small-diameter holes to drill, a corded electric drill will do fine. Newer 14.4V and higher-voltage cordless drills will be adequate for a limited
number of holes, but don’t try these jobs with smaller cordless models. If you have many holes to drill, or are boring holes of 3/8 in. dia. or larger, use a percussion drill, which is also known as a hammer drill. It will make the job go much faster.
There are so many variables in the composition, hardness and density of masonry materials that it’s not easy to provide rules of thumb for drilling, says Walter Knepper, president of DrilTec Inc., a Ridgeland, Mississippi–based bit manufacturer. It takes the right combination of pressure and drill speed, and trial and error is probably the best approach. After drilling a few holes, you should get a feel for what works best.
Although the list of anchors featured here is by no means comprehensive, it does include the ones most of you will need. Not included in the list are expensive epoxy
systems, cast-in-place anchors (which are used in new concrete construction) and
powder-actuated fasteners (which are driven by .22- or .25-caliber blanks). Powder-actuated fasteners are fast and versatile, and are available at most home centers or hardware stores. However, if you’re going to use powder-actuated fasteners, make sure you get training. There’s serious risk of injury if you do not use the tool correctly.
Plastic and Lead Anchors
Attaching a hose reel or a pair of shelf brackets to a wood surface is a fairly uncomplicated project. Try the same job on concrete, brick or stone, and it quickly becomes real work. Although there are special fasteners designed for these jobs, it’s easy to get confused about which to choose and how to install them so they’ll never budge.
Here, we show you the tools and techniques you need to work with masonry. We sort through the fasteners, pointing out which are best for the jobs most of us do once in a while, like attaching shelves to a concrete wall or hanging a trellis on brick.
Masonry anchors look different from one another, but they are alike in one respect: You’ll need to drill a hole in the base material. Often, the depth and diameter of the hole are crucial to the holding ability of the anchor. So you should always follow manufacturer’s instructions on hole depth and diameter carefully.
If you have only a few small-diameter holes to drill, a corded electric drill will do fine. Newer 14.4V and higher-voltage cordless drills will be adequate for a limited
number of holes, but don’t try these jobs with smaller cordless models. If you have many holes to drill, or are boring holes of 3/8 in. dia. or larger, use a percussion drill, which is also known as a hammer drill. It will make the job go much faster.
There are so many variables in the composition, hardness and density of masonry materials that it’s not easy to provide rules of thumb for drilling, says Walter Knepper, president of DrilTec Inc., a Ridgeland, Mississippi–based bit manufacturer. It takes the right combination of pressure and drill speed, and trial and error is probably the best approach. After drilling a few holes, you should get a feel for what works best.
Although the list of anchors featured here is by no means comprehensive, it does include the ones most of you will need. Not included in the list are expensive epoxy
systems, cast-in-place anchors (which are used in new concrete construction) and
powder-actuated fasteners (which are driven by .22- or .25-caliber blanks). Powder-actuated fasteners are fast and versatile, and are available at most home centers or hardware stores. However, if you’re going to use powder-actuated fasteners, make sure you get training. There’s serious risk of injury if you do not use the tool correctly.
Toggle
Toggle bolts are intended for use on hollow masonry materials, such as concrete block. To use, drill a slightly oversize hole and push the spring-loaded toggle through. Once the wings have cleared the hole, they open up. As the screw is tightened, the wings are drawn up against the backside of the block. Toggles are good for light loads, although larger sizes can handle medium loads. The screw portion of the toggle can be removed but the toggle itself cannot be retrieved.
Lag Shields
Relatively inexpensive and widely available, these internally threaded lead or alloy anchors are designed to work with lag screws in concrete and a variety of other masonry materials. Long lengths are used in softer base materials; short versions can be used in harder materials to cut drilling time. Lag shields are stronger than plastic anchors, but not as strong as expansion anchors like the wedge, sleeve or drop-in. A lag shield should fit snugly into its pilot hole, which is larger than the diameter of the fastener you intend to use. For example, an anchor for a 3/8-in. lag screw fits in a 5/8-in.-dia. hole. The hole should be deep enough so the lag screw doesn’t bottom out.
Concrete Screws
Introduced as Tapcons in the 1970s, and now available under a variety of trade names, these screws are popular among contractors because they are versatile and easy to install. Concrete screws are driven into slightly undersize holes, producing a snug friction fit. They work well in concrete, block and brick. Screws are available in diameters of 1/4 and 3/16 in., with hex and Phillips heads; they also come in stainless steel and coated carbon steel, so you can use them outside. Concrete screws, which are removable, will handle heavier working loads than many plastic and lead anchors. They require specially sized bits, usually sold with the fasteners.
Drop-In Anchors
Drop-ins are internally threaded to accept a machine bolt and sit flush with the surface. They are intended for concrete, although they can be used in some thicker stone materials. They require the use of a special setting tool that expands the anchor in the hole. Even relatively short drop-in anchors have high pullout and shear resistance, but they are best in dense base materials. Just like a lag shield, a drop-in anchor should fit snugly in a hole that is slightly larger than the machine bolt it’s designed for. Hole depth is critical.
Hammer-Driven Anchors
Although there are many varieties, hammer-driven anchors fall into two basic groups. One type consists of a screw or nail that expands a metal or plastic sleeve as it is driven into place. The other is a one-piece anchor that looks something like a crooked nail. A bend in the shaft compresses against the sides of the hole as the anchor is driven in with a hammer. You can use these anchors in concrete, block, brick or stone. Many are intended for light loads. Some types develop as much withdrawal resistance as a concrete screw of the same size, but once installed they don’t come out. Hammer-driven anchors fit in holes of the same nominal size: a 1/4-in. anchor gets a 1/4-in.-dia. hole.
Wedge and Sleeve Anchors
Although there are many varieties, hammer-driven anchors fall into two basic groups. One type consists of a screw or nail that expands a metal or plastic sleeve as it is driven into place. The other is a one-piece anchor that looks something like a crooked nail. A bend in the shaft compresses against the sides of the hole as the anchor is driven in with a hammer. You can use these anchors in concrete, block, brick or stone. Many are intended for light loads. Some types develop as much withdrawal resistance as a concrete screw of the same size, but once installed they don’t come out. Hammer-driven anchors fit in holes of the same nominal size: a 1/4-in. anchor gets a 1/4-in.-dia. hole.
Special Tools For Hard Spots
For drilling in masonry, you will need carbide-tipped bits designed for the work. The least expensive cost less than $3 and are fine if you drill only a few small holes once in a while. If you have more holes to drill, it’s worth looking for industrial-quality bits. They are machined, not twisted, and use higher grades of steel and carbide, both of which extend bit life. Although they only cost about $1 more than low-end models, they will last a lot longer. They are now available at some home centers (The Home Depot carries such a line) and hardware stores. If you don’t find them, check with an industrial-supply house, which you’ll find in the yellow pages.
For large jobs, step up from your rotary drill and use a percussion drill, sometimes called a hammer drill (tool-rental outlets usually carry them). These tools combine a turning motion with a high-frequency hammering action. Because they combine rotation and vibration, percussion drills are faster and more effective in concrete. And typically, these tools can be used in either a hammer mode or a standard rotary mode. Bits for percussion drills have a slight back-bevel on the carbide tip — called a negative angle — which helps prevent chipping. Many bits designed for percussion drills
also may be used in rotary drills.
For the really heavy stuff, there are rotary hammers, industrial-grade tools that turn more slowly than rotary or percussion drills and pound more forcefully on the end of the shank. These tools require special bits. When drilling in an unusually hard or abrasive material, like red brick and some types of stone, ask for bits with extra-hard carbide tips.