Surrey Contractor Fined after Roof Blaze Linked to Unsafe Hot Works

What happened

C Watkins Plumbing Limited has been fined following a fire that broke out on the roof of a 14-storey apartment building under construction in Staines-upon-Thames, Surrey. The incident occurred on 26 July 2024 at the Old Telephone Exchange development while four subcontractors were installing an air source heat pump. According to Roofing Today, sparks from welding ignited uncovered rigid foam insulation laid out across the roof. The resulting blaze rapidly spread across the whole roof space before running out of fuel.

The workers were forced to escape through a single opening and down a ladder to Level 14. There was no other route off the roof. Roofing Today reports that there was also no means of raising the alarm, nor were there fire extinguishers available on the roof at the time of the incident.

An investigation by the Health and Safety Executive (HSE) found that C Watkins Plumbing Limited had not properly planned, managed or monitored the hot works taking place. Despite the company’s own policies, there was no risk assessment, method statement, or permit to work in place for the welding. The failure to implement these procedures breached the company's legal duties under construction safety regulations.

Following a hearing at Staines Magistrates’ Court on 29 October 2026, C Watkins Plumbing Limited pleaded guilty to breaching Regulation 15(2) of the Construction (Design and Management) Regulations 2015. The company was fined £20,000 and ordered to pay £8,270 in costs.

The background

The HSE’s guidance document HSG168 (Fire Safety in Construction) sets out requirements for managing fire safety risks on sites. It specifies that fire safety measures need to be considered from the design stage, through procurement, and implemented fully during construction. A key point is that risk assessments are required to identify high-risk activities like hot works where fire can spread quickly, and to consider complex evacuation situations.

According to HSE guidance cited by Roofing Today, risk assessments and control measures must be regularly reviewed throughout construction to ensure they are suitable and effective. In this case, the HSE determined that C Watkins Plumbing Limited had systems and policies for managing hot works in place on paper, but failed to put them into action for this particular job. No permit to work was issued, and no direct controls were implemented for the welding activities being carried out over combustible insulation.

Contractors conducting hot works on roofs commonly face increased risk due to the use of open flames or tools that produce sparks near flammable materials such as foams, bitumen or membranes. Established procedures typically require a documented method statement, fire watches, available extinguishers, and a permit-to-work system to ensure risks have been thought through and mitigated for each scenario.

The Old Telephone Exchange project in Staines-upon-Thames was under construction in July 2024, with multiple subcontractors on site. Roofing Today reports that the contract chain placed the four workers under the direct control of C Watkins Plumbing Limited at the time of the incident. The insulation installed on the roof was uncovered, which contributed to the rapid growth of the fire once ignited by welding sparks.

What people are saying

Speaking after the case, HSE inspector Stephanie Hickford-Smith said Watkins had failed to follow its own procedures for hot works and had not assessed the risks. She said that as a result, there were "no control measures in place."

Hickford-Smith noted that "the four men working on the roof were lucky to escape." She added that if the fire had started closer to their escape route, or if the workers had not acted quickly, “the outcome could have been devastatingly different."

The HSE’s formal findings highlight a gap between policy and implementation, stating that the paperwork and systems must not just exist but be enforced operationally on site. Roofing Today reports that the court imposed the penalty after finding the company's failures put workers at significant risk.

What happens next

Following the court’s decision, C Watkins Plumbing Limited will be required not only to pay the fine and costs but also to review its site management procedures for hot works and fire safety. The HSE’s message in this case reiterates that companies must implement their stated safety policies in practice and that overlooking documented requirements can result in severe consequences.

For contractors and clients involved in hot works—especially on roofs and with flammable materials present—current HSE guidance and legal requirements will need to be checked carefully at every stage, from planning through to ongoing review as work progresses. Any failure to maintain suitable risk assessments, introduce control measures and manage permit-to-work systems will continue to be a focus of regulatory enforcement. Roofing Today reports no details on whether the project or its timeline have been affected by the fire, nor if further inspections are to follow at this site.