Beverley Magistrates court heard how, on 27 March 2015, an operative was installing a flue system for a biomass heating system at a farm in North Yorkshire.
He began by trying to use a ladder at the side of the outbuilding but when this was ineffectual, he resorted to climbing onto the roof to complete the works.
While working on the roof, the operative fell a distance of around 2 metres through the fragile cement sheet, suffering injuries including broken bones in the left ankle.
In the investigation HSE found the company had failed to adequately plan the installation of the heating system and the necessary work at height.
It was also heard at court at sentencing on 1 August how the company had failed to provide suitable work at height equipment such as a mobile elevated work platform, edge protection, crawl boards, a roof ladder or scaffolding.
Duncan Plumbing Heating and Electrics Ltd of Rudgate Business Park, Tockwith, North Yorkshire pleaded guilty to breaching Section 2(1) of the Health and Safety at Work Act 1974 and was fined £32,000 plus costs of £2,424.60.
After the hearing, HSE inspector James Harvey commented: “Work at height, such as roof work, is a high-risk activity that accounts for a high proportion of workplace serious injuries and fatalities each year.
“This case highlights the importance of following well-known industry guidance to plan and assess the work at height requirements needed to complete the work safely.”