CONTRACTORS have been accused of ignoring the potentially fatal risks associated with the misuse of anchors on construction sites.
A survey published this week by manufacturers group the Construction Fixings Association found specifications for fixings for uses such as cladding, structural steelwork and scaffolding are often ignored by workers on site, leading to incorrect installation and a risk of failure.
The survey found that 43 per cent of the engineers questioned recognised that their specifications for anchors are ignored or amended once they leave their hands.
Meanwhile, half of all the contractors questioned admitted they had no system in place to control alterations.
Almost six out of 10 contractors thought that it was not their responsibility to check any on-site amendments.
CFA chairman Paul Langford said: 'You have an engineer that will specify a fixing that could be safety-critical.
'To do this the engineer will look at all the relevant factors - the load, direction of forces, spacing between fixings, the concrete strength and the depth of the anchor.
They use highly advanced software to make this decision.
He added: 'The problem occurs when you get to site. A high percentage of contractors will change to another fixing that hasn't been specified.
'They just look at the load the new fixing is designed for.They see something that meets the load requirements for half the price and they go with it.
'They don't realise that it will not meet all the parameters set down by the engineer.'
Mr Langford gave an example where workers were struggling to drill into reinforced concrete, so inserted an anchor with a shorter plug length.Two days later the anchor failed, causing the whole slab to collapse.
The association is now advocating a two-step approach to beat the problem.
The first step is to increase understanding among contractors of the need to stick with the materials specified by engineers, or, where a decision is made to change, that decision is made by someone with the knowledge and technical competence to do so.
Mr Langford claimed moves toward more subcontractor working has reduced levels of training and supervision on site.
The second stage is to carry out a greater level of inspection to ensure the correct fixings have been used and that they have been fitted properly.
The CFA has published new guidance notes, which are available to view on its website at www. fixingscfa . co. uk.