Removing Concrete Anchors
There are several kinds of concrete anchors and each one of them requires a different method of removal. However, since they are installed in much the same way, they can be removed from the concrete in similar fashion, except for a few differences. In some cases, the removal of the anchors causes some form of damage to the concrete that can later be repaired by using a concrete patch.
Step 1 - Use a Screwdriver Bit
Some concrete anchors such as the Tapcon concrete screws can be removed easily by turning them counterclockwise. If the anchors are of the screw-in type, place a screwdriver bit into the drill, position the bit into the head of the anchor and turn the fastener loose in a counterclockwise direction. If the screw is tightly anchored to the concrete, proceed with the other methods below.
Step 2 - Use Wrenches, Pliers, or Vise Grips
If the anchor’s head is protruding from the surface of the concrete, grip it tightly with an adjustable wrench, pliers or vise grip. With sheer strength, twist the bolt loose from the concrete in a counterclockwise motion. Continue in this manner until the fastener comes loose. This works if the anchor is threaded. However, if the anchor is the wedge-in type, this may not work.
Step 3 - Pound the Anchor Loose
Some types of anchors are designed to grip to the base material and cannot be turned loose with wrenches. In this case, the only solution is to either cut it off from the base material or pound it loose. Be careful with the pounding though so as not to bend the anchor and cause more trouble. Wear safety glasses and protective gloves before proceeding. When pounding the anchor, aim for a direct and approximately 90 degree hit. If the strike is off-angle, it may bend the anchor. Keep pounding the anchor with a metal mallet until it comes loose from the base material. Pull the fastener out of the concrete.
Step 4 - Cut the Anchor Shaft
Some types of concrete anchors such as the strike anchor cannot be pounded or turned loose. In this case, it is best to cut them off from the base material. Use a hacksaw blade to cut through the shaft as close to the surface of the concrete wall or other surface as possible. If this method is not preferred, then proceed to the last resort.
Step 5 - Remove the Surrounding Concrete
Use a metal mallet and a metal wedge to chip off the concrete surrounding the anchor. Be sure to wear safety gear before proceeding. Chip the concrete until the entire length of the fastener is exposed so you can pull it out.
Step 6 - Patch the Damaged Concrete
Mix concrete patching mortar and patch the entire hole completely. Ensure that the concrete patch is level with the surface. Allow the mortar to cure before applying some finishing coat such as paint.