Jul 2018 HOW TO REMOVE CONCRETE FASTENERS FROM BASE MATERIAL
Although not always a desirable deed, it is possible to successfully remove both male and female concrete fasteners once set into a base material. By following tried and tested steps, Sephaku Cement explains the ideal process to removing both types of concrete fasteners while maintaining the integrity (and aesthetics) of the concrete base in which the fasteners have been secured.
What is a Concrete Fastener?
Characterised by screw-in anchors, concrete fasteners also referred to as concrete anchors that are installed by making an initial hole in a concrete base, inserting a variety of anchor types into the hole to fill the space and then expanding material in the hole using a nail, screw or setting tool.
Common Types of concrete Fasteners include:
- Wedge Anchors
- Sleeve Anchors
- Concrete Screws
- Drop-In Anchor
- Machine Screw Anchor
- Strike Anchor
- Hammer Drive Anchor
- Split Drive Anchor
- Lag Shield
Concrete anchors can be differentiated by male versus female features.
- Male Concrete anchors are characterised by fasteners that protrude from the base material.
- Female Concrete fasteners are located below the surface of the concrete base, secured by a bolt inserted through the fixture.
When removing concrete fasteners, the force required is referred to as the ultimate pull-out or ultimate tension load. The amount of force needed is determined by the diameter of the anchor and the depth at which the anchor has been sunken into the base.
Where each type of concrete fastener calls for a different approach when removing, see to follow various methods to removing male and female variants of concrete anchors.
Male Concrete Anchors
- Wedge anchors – Its best to install these anchors by drilling twice the depth length. In doing so to remove, all that is required is to hammer the anchor deeper into the base whereby the protrusion is plush to the base material. Alternatively using a hacksaw or cut-off wheel simply saw off the Wedge anchor to the concrete base.
- Tapcon Concrete Screws – one of the easier anchors to remove simply turn the threaded screw of the tap threads in a counter-clockwise direction until the concrete screw has threaded its way out of the base material.
- Sleeve Anchors – Similar to Wedge Anchors, following installation simply remove the nut, washer and round or flat head of the sleeve anchor. Hammer the threaded stud to align with the base material and cut off using a hacksaw or cut-off wheel.
- Hammer Drive Anchors – A little trickier to remove, these have a tamper resistant head that will need to first be cut away in order to extract the full installation. Once the head has been successfully removed using a hacksaw or cut-off wheel, the body of the anchor can be drilled out using a high speed bit.
- Strike Anchor – These can only be removed by cutting the protrusion off to sit plush to the base.
- Split Drive Anchor – Also equipped with a tamper resistant head, these concrete fasteners can only be removed by cutting them back with a hacksaw or cut-off wheel (with great difficulty given their design and installation).
Female Concrete Fasteners
- Drop in Anchors – using a setting tool Drop in Anchors are installed beneath the surface of the concrete base and cannot be successfully removed without damaging the concrete. However, once the bolt or threaded rod has been removed the drop in anchor
- Lag Shield Anchors – because these are installed by inserting a lag screw that expands the Lag Shield Anchor into the base, by simply removing the screw will reverse the anchor.
- Machine Screw Anchors – set into the base using a setting tool, these concrete fasteners cannot be removed. Although much in the same as Drop in Anchors, by removing the bolt and fixture the anchor can remain in place hardly visible as it is set beneath the surface of the concrete base.
Whether removing concrete fasteners from concrete, brick or block, ideal circumstances would be to know ahead of installation if the concrete anchor will need to be removed at a later stage. With this knowledge a more versatile anchor can initially be installed, that is easier to remove when the need arises in the future.