Four workers fled 14-storey roof fire; plumbing firm fined £20,000

C Watkins Plumbing Limited has been fined £20,000 after four workers fled a fire that engulfed the roof of a 14-storey apartment block under construction in Surrey.

The subcontractors were installing an air source heat pump on the roof of the Old Telephone Exchange development in Staines-upon-Thames on 26 July 2024. Sparks from welding work ignited uncovered rigid foam insulation laid across the roof. The self-sustaining fire spread quickly, consuming the entire roof space before burning itself out when it ran out of fuel.

The four men escaped through a single opening in the floor and down a ladder to Level 14. There was no other way off the roof. There was no means of raising the alarm. There were no fire extinguishers.

What did the HSE investigation find?

The Health and Safety Executive (HSE), Britain's workplace safety regulator, found the company had failed to plan, manage and monitor the hot works (welding, cutting and other spark-generating tasks) on the roof.

Despite company policies requiring them:

• No risk assessment was in place
• No method statement existed
• No permit to work was issued for the welding

C Watkins Plumbing Limited, of Ramsgate, Kent, pleaded guilty to breaching safety regulations. It was fined £20,000 and ordered to pay £8,270 in costs at Staines Magistrates' Court last week.

HSE inspector Stephanie Hickford-Smith said: "Watkins failed to follow its own procedures for hot works. It did not assess the risks and so had no control measures in place."

She added: "The four men working on the roof were lucky to escape. Had the fire started closer to their escape route, or had they not acted as quickly as they did, the outcome could have been devastatingly different."

Surrey Fire and Rescue Service photographed the aftermath, showing the charred remains of the roof space.

What does this change for contractors?

The case turns on a simple point: written policies mean nothing without execution. Watkins had hot works procedures on paper, but the HSE found no risk assessment, no method statement and no permit on site. For firms running rooftop mechanical installations, the verdict confirms that regulators and courts will treat an unimplemented policy as an aggravating failure, not a defence.

The company's response

Marc Harris, Group Services Director at C Watkins Plumbing, said: "We are very sorry that this fire happened in 2024 and for any harm it may have caused. We accepted responsibility from the outset, co-operated fully with the HSE and pleaded guilty at the first opportunity."

He said the court found the company's culpability to be low, recognising its long-standing safety record and existing procedures.

"Since the incident we have carried out a full independent review of our safety systems, removed welding from our site activities, retrained our workforce and updated our hot works risk assessment and induction procedures, and we continue to audit our hot works and safety procedures regularly," Harris said.

The removal of welding from all site activities is the most concrete outcome. Other contractors carrying out rooftop hot works near foam insulation, a common pairing on heat pump retrofits, now have a documented example of the £20,000-plus cost of skipping the permit process — and of how close four workers came to paying far more.