Plumbing contractor fined £20,000 after welding sparks set 14-storey Staines roof alight

C Watkins Plumbing Limited has been fined £20,000 after four subcontractors under its control had to flee a fire that engulfed the roof of a 14-storey apartment block under construction in Staines-upon-Thames, Surrey, the Health and Safety Executive (HSE) said.

The company, of Ramsgate, Kent, pleaded guilty to breaching Regulation 15(2) of the Construction (Design and Management) Regulations 2015 at Staines Magistrates' Court on 29 October 2026. It was also ordered to pay £8,270 in costs.

According to HSE, the four men were installing an air source heat pump on the roof of the Old Telephone Exchange development on 26 July 2024 when sparks from welding ignited uncovered rigid foam insulation laid across the roof. The fire spread across the whole roof before burning itself out when it ran out of fuel.

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."

The escape

The workers got off the roof through a single opening in the floor and down a ladder to Level 14, HSE said. There was no other way off the roof, no means of raising the alarm and no fire extinguishers.

An HSE inspector who happened to be nearby photographed the block ablaze, and Surrey Fire and Rescue Service photographed the aftermath. HSE published the images alongside its release.

Hickford-Smith said: "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."

The breach

HSE's investigation found the company had failed to plan, manage and monitor the hot works on the roof. Although the company's own policies required them, there was no risk assessment or method statement in place and no permit to work was issued for the welding, the regulator said.

Regulation 15 of CDM 2015 sets out the duties of contractors. Paragraph (2) requires a contractor to plan, manage and monitor construction work carried out by it or under its control, according to the legislation published on legislation.gov.uk.

Companies House lists the company's registered office as Watkins House, Leigh Road, Haine Industrial Park, Ramsgate, Kent. Its registered activities include plumbing, heat and air-conditioning installation and electrical installation.

HSE's guidance

In its release, HSE pointed to its guidance HSG168, Fire safety in construction, which says fire safety measures must be considered throughout design and procurement and implemented during construction. Risk assessments must identify high-risk activities where fires can spread quickly, and situations where evacuation plans are complex, and must be reviewed throughout the construction phase, the regulator said.

HSE says HSG168 is aimed at all those who procure, design, develop and manage construction sites, including clients and designers. The regulator estimates there are hundreds of fires on construction sites each year.

HSE's construction fire guidance says fire extinguishers are also needed for those carrying out hot work, and that the primary purpose of an extinguisher on site is to aid escape from a fire. It says a site fire warning signal should be distinctive and audible above other site noise, and that larger sites require an interconnected system of call points and sounders.

The site

Spelthorne Borough Council's planning records describe the scheme at the former Old Telephone Exchange on Elmsleigh Road, Staines-upon-Thames, as the redevelopment of the site to provide 206 dwellings together with car and cycle parking.

The council's planning committee considered application 24/01268/RVC for the site in January 2025, when it deferred the application. In February 2025 the committee resolved to approve it subject to completion of a Section 106 agreement.

The HSE prosecution was brought by senior enforcement lawyers James Towey and Laura Lax and paralegal officer Farhat Basir. HSE said it does not pass sentences, set guidelines or collect any fines imposed.