Troubleshooting Wedge Anchor
Problem: Wedge anchor is spinning in the hole
Trouble Shooting Tips:
- The hole might have been drilled using a rotation drill rather than a hammer drill. The hole may not meet the correct tolerances for the wedge anchor needed to achieve holding values. Hole tolerance is critical; therefore, a hammer drill must be used with a carbide tipped bit that meets ANSI standards to ensure proper hole size.
- The nut might have been over torqued causing the concrete to break apart in the hole where the expansion clip expands. Each diameter of wedge anchor needs to be torqued to a specific range that is specified by the manufacturer. Try to pound the anchor deeper into the hole and re-torque the wedge anchor to the proper torque as suggested by the chart below:
Diameter |
Torque Ft/lbs |
|---|---|
| 1/4” | 4 |
| 3/8” | 25 |
| 1/2” | 55 |
| 5/8” | 90 |
| 3/4” | 110 |
| 7/8” | 250 |
| 1” | 300 |
- A piece of aggregate may have been broken loose during the drilling process right where the clip was expanding. The anchor should be pounded further into the hole with an attempt to torque the wedge anchors to the proper torque value.
- The concrete may still be green and not fully set. Concrete must be a minimum of 28 days old before a wedge anchor should be installed into it. Waiting for the concrete to set will allow the wedge anchor to properly expand.
Problem: Unable to expand the wedge anchor
Trouble Shooting Tips:
- The hole drilled in the concrete is not the correct diameter. The diameter of the hole should be equal to the diameter of the wedge anchor being installed.
- A minimum of 3 to 5 threads must be below the surface of the concrete or the surface of the material being fastened. This allows for the wedge anchor body to be pulled up and to wedge the clip in the hole.
Problem: Wedge anchor does not fit through hole in the item being fastened
Trouble Shooting Tips:
- The designated diameter measurement of a wedge anchor is larger than a true measurement. The hole in the item being fastened must be slightly larger than the wedge anchor that is being inserted. The threaded end of the wedge anchor is equal to a true measurement. It will fit through a hole in the item being fastened if the item is placed over the threaded end.
Problem: Wedge anchor does not fit into hole drilled into the concrete
Trouble Shooting Tips:
- The wrong diameter of carbide tipped hammer drill bit may have been used. The correct diameter bit to use is equal to the diameter of wedge anchor being installed.
- A straight rotation drill may have been used to drill the hole in the concrete. A hammer drill that is set in the hammer and rotation mode must be used to ensure proper hole tolerance.
- The carbide tipped bit used to drill the hole may not have met ANSI standards. An ANSI standard bit must be used to ensure proper hole tolerance and anchor diameter requirements.
Problem: Wedge anchor is bottoming out in the hole.
Trouble Shooting Tips:
- While a deeper hole will not affect the wedge anchor’s installation, a too shallow hole will affect installation. The hole must be drilled deep enough so that a minimum of 3 to 5 threads is below the surface of the concrete or below the surface of the fixture. The wedge anchor does not need the bottom of the hole to expand properly. The hole needs to be drilled a minimum of 1/2” deeper than the planned depth that the wedge anchor will be embedded in the concrete. This allows space for any dust or debris to fall into and out of the way and extra space to ensure proper installation.
Wedge anchor body is bending when I pound it into the concrete.
Trouble Shooting Tips:
- To heavy of a hammer is being used. For smaller diameter such as 1/4”, 5/16” and 3/8” not much force is needed, a light hammer may work.
- Not striking the wedge anchor square with the hammer may make it bend as it is being inserted into the concrete.
- Trying to embed a wedge anchor at deeper embedments. Trying to embed a wedge anchor 8” or more into the concrete may create a bending problem. The ability to drill a perfectly straight hole deeper than about 8” is very difficult. The wedge anchor will hit the side of the hole in the concrete and then start to bend as the hammer strikes it.
Removal of Wedge Anchor
Trouble Shooting Tips:
Wedge anchors are designed not to come out. They cannot be removed without damaging the concrete they are installed in.
- The wedge anchor can be cut off at the surface using a hacksaw or cut off saw.
- When drilling the hole, drill it the length of the hole equal to the length of the wedge anchor being installed plus 1/2”. This will allow the wedge anchor to be pounded into the concrete flush with the surface. Wedge anchors are designed to go into the hole and can be pounded into the concrete even after they have been set.
Security Wedge Anchors
Trouble Shooting Tips:
To make the wedge anchor a security fastener damage the threads above the nut once the wedge anchor is set in the concrete. Damage the threads by cutting or deforming them to ensure that the nut cannot be removed.
