Introduction
Fibreglass, sometimes called fibre reinforced plastic, is a composite, consisting of glass fibres set in a solid plastic such as polyester or epoxy. Fibreglass is distinctly different to the lightweight glass fibre mats used for insulation.
Well made, it has a remarkable strength to weight ratio and excellent corrosion resistance. One of its applications is in the construction of tanks to contain water or process fluids. It is this application that has given rise to the majority of the failures that our forensic experts have been asked to investigate.

Characteristics of Fibreglass Failures
Fibreglass is not very forgiving to poor design, faulty construction or to misuse. An unusual feature of fibreglass failures is that a significant proportion of failures originate not from the fiberglass itself, but from the deterioration of steel fasteners or lugs incorporated into the construction.

The Need for Inspection
For at least 50% of the failures we have examined, there were clear signs of impending problems. Sometimes these signs were apparent externally, while with others the tank would have had to be emptied for the deterioration to be apparent. The lesson to be learnt is that a good proportion of failures could be prevented by regular inspection.

It can also be concluded that deterioration can begin soon after manufacture. Experience has shown the incorrectness of the belief that there is an initial time interval during which fibreglass tanks do not need to be inspected.