NHS England hospitals have sounded the alarm over materials used in roofs that reached the end of their lifespan more than a decade ago.

Several hospitals are warning of the potential for roof collapses due to structural weaknesses in the reinforced concrete planks used in their construction between the 1960s and 1980s, which have a 30-year lifespan.

According to reports, North West Anglia NHS foundation trust wrote in its annual plan that the poor condition of the main theatres in Hinchingbrooke hospital in Huntingdon, Cambridgeshire, posed a significant risk to elective care. Published in June, the plan said that the hospital had been forced to restrict the use of some theatres to patients weighing less than 120kg.

Since the report, more structural surveys have been undertaken and the hospital is able to use just one of its seven operating theatres for patients weighing more than 120kg. The hospital said it had received £13m this year to cover the costs of surveys and repairs.

Leaked reports to the BBC show that West Suffolk hospital, which has a similar design to Hinchingbrooke, had hired a law firm to investigate the potential for corporate manslaughter charges in the event of a fatal roof collapse, while hospital trusts in eastern England had produced an emergency plan outlining what would happen in the event of ‘significant hospital structural failure’.

An initial risk assessment that warned of an ‘almost certain’ plank collapse, which would have ‘catastrophic’ consequences. The risk level has since been downgraded to ‘likely’ in response to West Suffolk launching a multimillion-pound safety works programme, though it is understood this will not be completed until spring 2023.

NHS England said the affected trusts were maintaining safe services and were regularly required to manage complex estates repairs, including roofing work. It added that training exercises were regularly conducted in the interests of safety and preparedness.