The 61-year-old was working for Camclad Contractors Limited, replacing cladding panels on a former abattoir that had been damaged in a storm, when the incident took place at Gaerwen Industrial Estate, Anglesey, on 24 January 2018.

An HSE investigation found that the work had only been planned from photographs and that no site visit had taken place before starting the job.

The dimensions of the building were not known to the contractor. This meant  the cherry picker hired to allow safe access to height did not reach all parts of the structure that were to be repaired.

To complete the job workers had to leave the safety of the cherry picker basket and use boards found on site to work on the fragile roof. It was whilst doing this that the victim slipped and fell through the fragile roof, landing on the concrete floor below.

Camclad Contractors Limited of Wyboston, Bedfordshire pleaded guilty to breaching safety regulations and was  fined £225,000 and ordered to pay costs of £10,000.

A director of the company, Dominic Lakeman-Pettit also of Wyboston, Bedfordshire pleaded guilty and was sentenced to four months in prison suspended for 12 months and ordered to carry out 200 hours unpaid work. He was also ordered to pay costs of £1,000.

Speaking after the case HSE principal inspector Damian Corbett said: “Those in control of work have a responsibility to devise safe methods of working and to provide the necessary information and instruction to their workers in the safe system of working.

“If the work had been adequately planned, it would have provided a suitable safe system of work and prevented the risk of falls through fragile materials. Companies should be aware that HSE will not hesitate to take appropriate enforcement action against those who fall below the required standards.”