Two building firms have been fined for safety failings after a worker was injured when he fell through a roof on site.

The 46-year-old worker from Tunbridge Wells, who does not wish to be named, fell through the fragile roof of a food packaging firm’s premises in Bridge after losing his balance on the working platform he was using.

He landed on the roof nearly six feet below him and suffered a broken rib and fractured left wrist.

The incident, on October 4, 2012, was investigated by the Health and Safety Executive (HSE) which prosecuted Ramsgate-based firms WW Martin Ltd and Brandclad Ltd.

Canterbury Magistrates were told the food firm had used WW Martin for several years to carry out building work at their site and contracted them to fix leaks in the premises.

WW Martin then hired specialist roofing firm Brandclad to carry out the work.

Before the repairs started, WW Martin were sent a risk assessment and planned method of work by Brandclad which highlighted the danger of the roof and stated that platforms with handrails and harnesses would be used.

However, HSE found that from the start of work on September 22 until a month later when the work finished, the platforms were left open and unprotected.

“This was a completely avoidable incident. The dangers of working on fragile roofs are very well- known in the industry" - HSE Inspector Melvyn Stancliffe

Even after the Brandclad employee fell and work was suspended for ten days, the only change made was to provide platforms that sat flatter and more evenly.

The handrails and harnesses promised were never used by Brandclad and WW Martin, responsible for monitoring the work, failed to take any action.

Magistrates heard HSE was told that both WW Martin and Brandclad had considered using the prevention measures but decided against it because of doubts about the structural strength.

WW Martin Ltd, of Dane Park Road, Ramsgate, and Brandclad Ltd, of North Farm Road, Tunbridge Wells, each admitted one breach of the Work at Height Regulations 2005.

Brandclad, stated by the court to be 60% culpable, was fined £7,000 and WW Martin was fined £10,000 as a result of its stronger financial position despite being 40 per cent culpable.

HSE Inspector Melvyn Stancliffe said: “This was a completely avoidable incident. The dangers of working on fragile roofs are very well- known in the industry.

"Such work should never be undertaken without careful planning and making sure the right type of fall prevention and mitigation measures are in place.

“It is incredible the work was carried out despite the companies’ misgivings about the strength of the internal cold store roof. Had that given way when the worker fell on to it then HSE would likely have been investigating a death.

“Even after the incident, the job was resumed without any proper improvements made to the working methods. There should be no shortcuts when working on fragile surfaces – no matter how short the duration of a job is.”

The worker from Tunbridge Wells has since recovered and returned to work.