Once installed, concrete fasteners such as wedge anchors are generally designed to stay put. Because they are often used to secure heavy machinery or structural framework, they are meant to be permanent.
And while other types of fasteners—such as toggle bolt anchors, sleeve anchors, steel drywall anchors, anchor bolts, and butterfly anchors—aren’t usually tasked with such heavy-duty responsibilities, many renovation and construction projects call for situations where a variety of types of anchors must be removed. Doing so requires careful planning, because attempting to remove anchors the wrong way can result in damage to the wall or other base material where the anchors have been set.
Before attempting to remove anchors from concrete or other material, you can research the amount of force needed, which is referred to as the ultimate tension load. This force, or pull-out value difficulty, is measured by both the diameter of the anchor and the embedment depth into the base material.
When installing anchors, a good course of action is to consider ahead of time whether they might someday need to be replaced. This might dictate not only the specific type of anchors you choose for the job at hand, but also how you install them.
Below are the most common types of anchors and some suggestions for ways to remove them with minimal hassles. However, additional research is recommended before proceeding with a specific removal project.
Wedge Anchors
When using wedge anchors to fasten something into concrete, it’s smart to plan ahead during the installation process and drill twice the length of the wedge anchor into a concrete floor or wall. This way, removal of unneeded wedge anchors should be as simple as pounding the anchor back into the hole until it is flush with the surface. Your other option is to use a grinder saw or hacksaw to cut away at the bolt.
Steel Drywall Anchors
Metal wall anchors can be a challenge to remove because they feature a metal collar on the outside that grabs the drywall while metal prongs grab onto the drywall from the inside. To rid yourself of steel anchors that once held shelves or other furniture in place, your first step is to remove the screw from the anchor using a drill or screwdriver. After doing so, choose a drill bit roughly two sizes larger than the diameter of the hole in the visible metal collar portion of the anchor. The edges of your drill bit should only come in contact with the edges around the screw hole and not ever extend into the hole. With the hole serving to center the bit, start drilling. When the collar and anchor separate, the drill bit should push the anchor out of the drywall and into the space between the wall and the drywall. Mission accomplished.
Butterfly Anchors
Also known as toggle bolts, these anchors feature metal “wings” that spring open and stay flush inside the wall to hold a surprising amount of weight. In fact, a ⅛" butterfly anchor can hold from 100 - 300 lbs., depending on the thickness of the wallboard where it is inserted. To remove, first snap off the collar by bending it downward with a needle nose plier until it breaks off. You can then push the anchor through the wall using a nail.
Lag Shield Anchors
These anchors require the insertion of what’s known as a lag screw that expands the lag shield anchor. In many cases, taking out these anchors can be done by simply removing the screw in the center, which causes the anchor to contract and then be pulled out of the drill hole. If this doesn’t work, try brute force and use a needle nose pliers to yank the anchor out of the hole.
Strike Anchors
These anchors can only be removed by using a grinder saw or hacksaw. Strike anchors, which are steel impact-type expansion anchors set into concrete by pounding with a hammer, feature an all-in-one design without components that can be separated to assist with removal.
Split Drive Anchors
Split drive anchors typically have a countersunk or round head for tamper resistance and can only be dealt with by cutting off the head of the anchor with a saw.
Drop-In and Machine Screw Anchors
These anchors are made to be inserted or dropped into concrete or another base material using a setting tool. Once these anchors are set, they cannot be removed without gouging into the concrete surface. Your best bet is to remove the threaded rod from the anchor. This leaves the anchor inside the wall, making it relatively easy to simply patch over the anchor and move on.
Following the above steps can ensure your construction project doesn’t require additional work by having to unnecessarily repair damaged drywall or concrete floors during the removal of pesky and unwanted anchors.
Product Compliance and Suitability
The product statements contained in this guide are intended for general informational purposes only. Such product statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand and follow all manufacturer instructions.