How to Remove a Concrete Anchor Bolt
Concrete anchor bolts are meant to stay put. These special bolts attach concrete to different structures and, if installed correctly, are extremely difficult to remove. However, even the toughest bolts can be removed if you use enough strength. To remove a concrete anchor bolt by yourself, try one of these tricks.
Warning: When using any of these suggested methods, always wear the appropriate safety gear as suggested by your tool's manufacturer.
Step 1 – Use a Pry Bar and Hammer
First, place your pry bar against the plate of the anchor. Then, use a hammer to strike the pry bar, so that it becomes lodged under the anchor plate.
Step 2 – Bend the Anchor Plate
Using your strength, press down on the anchor plate to bend as much of it upward as possible. Use pliers to get a better grip.
Step 3 – Drill Holes
You may need to drill holes into the plate and use a hammer to chip away at it. Eventually, you will see the concrete anchor bolt.
Step 4 – Grind the Bolt
Use a grinder to cut the anchor bolt, and then grind the bolt down until it’s flush with the concrete. If these steps don't work, trying using threaded nuts.
Using Threaded Nuts
Step 1 – Place the Threaded Nut
Place the threaded nut onto the concrete anchor bolt. Make sure it's tight and flush with the bolt’s upper side.
Step 2 – Grip With Pliers
Then, grip the nut with pliers, and pull upward. If the concrete anchor bolt was not properly set, this method will work quickly. If the bolt it still stuck, use a 2x4 with the following method.
Using a 2x4
Step 1 – Place 2x4
Place one end of a 2x4 on top of the concrete anchor bolt. Hold the other end of the 2x4.
Step 2 – Strike the 2x4
Using a small mallet, strike the 2x4 with increasing velocity. The bolt should loosen enough for you to remove it. Be careful using this method. You don’t want to break the 2x4, but also you don’t want to accidentally strike the bolt, as the bolt could bend.
Using a Pipe Wrench or Vice Grips
Step 1 – Use Your Tool as Leverage
Grip the top of the concrete anchor bolt with either the pipe wrench or vice grips. Use the leverage provided by your tool until the bolt comes loose. Make sure the bolt stays straight during this step.
Step 2 – Increase Torque
If the above technique doesn’t work, you can add a pipe to the end of the pipe wrench. Or, twist the wrench slowly to increase torque.