Anchor installation errors are a prevailing issue within the M&E industry.
It is estimated that up to 80% of all ‘drop in’ anchors are installed incorrectly, worryingly these are commonly used for overhead safety-critical applications.
As previously discussed through our Sound-Out series there are two key reasons why anchor installation failure occurs.
- Selecting the wrong anchor (the selection criteria has not been carried out)
- The installer is not capable of installing an anchor to the correct standard.
Common Anchor Installation Errors
- Setting tools
Selecting the wrong setting tool for anchor installation is a common error. For wedge anchors fixed within overhead applications, using an SDS setting tool generally makes the whole installation process easier and quicker.Setting Tools
- Torque correctly
Over-tightening concrete screws can strip the thread and cause undue stress on the substrate and under torquing a concrete screw runs the risk of the fixture moving after load relaxation. As a rule of thumb, turn the anchor by no more than ¼ turn from when the head makes contact with the fixture or substrate. When an anchor has been correctly torqued it can achieve its maximum load and that there is no damage to the anchor or substrate.
According to BS 8539 anchors should be tightened to the manufacture’s recommended torque settings.
- Drill the correct sized hole
Holes drilled should be the correct diameter and depth. Using a worn drill bit results in undersized holes makes installation difficult and increases stress in the anchor material. Make sure you inspect drill bits frequently and where possible use a PGM stamped accredited drill bit.Installation Instructions
- Cleaning holes
Cleaning holes with wire brushes and dust removal pumps or vacuum cleaners is essential to ensure the integrity of chemical anchors. During drilling, the drill bit compresses dust onto the surface of the hole. Often using a blow-out pump is not enough for dislocating dust and removing it, the resin can bond to the dust rather than the substrate. Often a combination of brush and blow-out pumps is the best method. It is also important to follow the manufacturer’s cleaning instructions to achieve the correct bond strength.How do I correctly Install an anchor?
BS 8539 guidance
BS 8539 defines competent as: “suitably trained and qualified by knowledge and practical experience, and provided with the necessary instructions, to enable the required task(s) to be carried out correctly”.BS 8539:2012 guide
How can MIDFIX help?
MIDFIX is the only UK M&E supplier that can offer a complete anchor/fixing policy. With our knowledge and deep understanding, MIDFIX can help select the correct anchor, ensure a reliable supply, provide installation training through the MIDFIX Academy and carry out on-site anchor testing.
There are some useful installation guides on the Construction Fixing Association website. Anchors are a small component to which little consideration is frequently given but are vital to preventing the collapse of the structure or installation that depends on them. With the right training, you can reduce the risk of anchor installation errors.