Find the right anchor for every situation
Unlike wood and drywall, stone, brick and concrete surfaces are a little less likely to give way with ease when you try to drive in a fastener. Fortunately, there is a whole range of anchors specially made for working with these surfaces, and the good news is that with the help of a few basic tools, they' re pretty easy to work with. Choosing the appropriate anchor from a wide variety of available options, including sleeve anchors, toggle bolts, concrete screws and more, can be overwhelming. With a little bit of knowledge, however, you'll be sure to find what you need. Consider the following questions as you try to find the right type of anchor for your next project:
Applications, Usage, Types and Insertion
Whether you're securing a set of shelves to a basement wall, installing a new light fixture in the brick façade on the front of your house or hanging tool storage in your garage, masonry and concrete anchors will come in handy. Understanding the different types of loads they are able to bear and what kind of loads different objects create is key to choosing the best type of anchor to use. Once you've selected the right anchor for the job, you'll need to make sure you have the necessary tools on hand for installation. In some cases, a hammer drill may provide more utility than a standard cordless drill.
Applications and Loads: Anchors are used in situations where it's either impossible or impractical to insert a screw directly into a wall, such as when working with concrete or drywall. Once the anchor has been secured, a screw is inserted to hang a variety of different objects ranging from shelves and cabinets to paintings and mirrors. Anchors are subject to pull in two different directions. The shear load describes the amount of downward force gravity and the weight an object exerts on an anchor. Tensile load refers to the amount of force required to pull the anchor straight out of the hole. Both of these loads must be taken into consideration when installing an anchor. In order to make sure your anchors can safely hold the weight of the object you're attaching, a good rule of thumb is to assume that they can hold 1/4 of their stated load. For example, if an anchor is rated to hold 100 lbs., assume it can safely handle 25 lbs. Then, simply use a number of anchors whose total load when added up and divided by four is equal to or greater than the weight of the object being hung.
Types: Masonry and concrete anchors are available in many different varieties. Generally, anchors function either by expanding once they're in place to provide a strong hold or by friction. The chart below lists some of the more commonly used types, the applications they're best suited for and a few points of consideration.
|Anchor Type||Applications||Points to Consider|
|Concrete Screws||Used for various applications in concrete, brick or block, such as attaching furring strips, doors and electrical boxes.||
|Hammer-In Anchors||Various applications in concrete, concrete block, mortar and brick, such as hanging furring strips and metal brackets.||
|Lag Shields||Longer shields are best for use in hard masonry while shorter shields are better for softer materials.||
|Lead Screw Anchors||Securing light to medium loads in brick, concrete block and masonry.||
|Plastic Wall Plug||Light-duty applications in masonry, such as towel bars, tool brackets and shower doors.||
|Sleeve Anchors||Medium-duty applications in concrete block, such as anchoring handrails, decks, machinery and shelves.||
|Toggle Bolts||Light to medium loads in hollow block.||
|Wedge Anchors||Heavy-duty load applications in concrete blocks and thin-wall or solid concrete, such as anchoring machinery and attaching framing members.||
Insertion Tips and Tools: Regardless of which type of anchor you select, you're going to need to drill a pilot hole. Masonry and concrete are tough surfaces to drill through, so make sure you have plenty of extra bits on hand. Some anchors will require spotting prior to insertion. Spotting involves positioning the fixture to ensure the fasteners will be secured in the correct spot prior to drilling a pilot hole. Others, referred to as one-step anchors, do not need to be spotted. Once you've drilled your pilot hole, use a can of compressed air or a blower to clean out the hole. Excess debris can prevent the anchor from being properly secured. Avoid placing anchors too close to each other or the edge of the surface you're working with, as the stress may cause it to fracture.
Chemical and Powder-Actuated Anchors: All of the anchors discussed above are mechanical anchors. If you're working with an extremely heavy object that requires an industrial-strength hold, you may want to consider using a chemical or powder-actuated anchor. These anchors use chemicals such as epoxy to strengthen the bond. They are not required for most household applications, however, and you'll need special training and possibly a license before being able to use them.
Antirotation Fins: This feature prevents anchors from spinning while they are being inserted, which strengthens their hold once inside the wall.
Hammer Drill: Regular drills work well for installing anchors in wood and drywall. Stone, concrete and brick, however, can prove to be tough customers. Hammer drills combine the driving force of a drill with the pounding action of a hammer, making it easier to bore into hard surfaces. If you don't plan to undertake a lot of projects involving masonry and concrete, consider renting a hammer drill from The Home Depot.
Drilling your way through hard stone and concrete can wear down drill bits pretty quickly. Check out The Home Depot’s selection of drills and bits to make sure you have the necessary equipment on hand to get the job done right.