Dozens of schools have been built using combustible insulation since the material was banned on high-rise apartment blocks after the Grenfell Tower disaster, raising fears for children’s safety. More than 70 schools are likely to have used plastic foam insulation, which burns, since it was banned on residential buildings over 18 metres in height in December 2018, according to industry research. The study by the insulation manufacturer Rockwool also found about 25 recently built hospitals, care homes and sheltered housing complexes that were likely to have been constructed with combustible insulation. The figures are thought to be an underestimate. It comes after the Department for Education last Thursday unveiled new fire safety proposals for schools buildings that would continue to allow combustible cladding on structures below 18 metres in height. The government closed a separate consultation on whether to extend its ban on combustible materials to shorter buildings a year ago, but has not yet announced its findings. Geoff Barton, the general secretary of the Association of School and College Leaders, said the figures were a “major cause for concern … Action rather than discussion is needed now to remove and replace high-risk combustible materials and ensure the safety of young people and education staff,” he said. Among the schools using combustible insulation is the Joseph Leckie academy in Walsall, in the West Midlands, which has used the same Kingspan insulation that was used on Grenfell Tower. The academy did not respond to a request for comment. Others schools have used the kind of high-pressure laminate panels that were used on the Cube student housing block in Bolton that went up in flames in 2019. In the last five years, 47 primary and secondary school buildings have been destroyed by fire in England, according to the insurer Zurich, which estimates that more than 390,000 teaching hours could be lost in the next year due to school fires. The insurer and the National Fire Chiefs Council are calling for sprinklers to be mandatory in new and refurbished schools. Dr Mary Bousted, the joint general secretary of the National Education Union, said: “It is clearly very unwise to choose to use insulation material that makes a school more likely to suffer a fire. Not only does it risk lives, but [there is] also disruption to education – not to mention the cost to the taxpayer in putting things right following a major fire.” Since the 2017 Grenfell disaster, only housing blocks more than 18 metres in height are banned from using combustible materials on their facades. But there have been several serious fires in shorter buildings since the tragedy, including the Cube fire and another in 2019 at Samuel Garside House, a block with wooden cladding in Barking, London. MPs, firefighters, the Construction Industry Council and the mayor of London, Sadiq Khan, are among those calling for the ban to be extended to schools. The Department for Education last week launched a consultation on new fire safety guidance for schools requiring non-combustible cladding on school buildings that are above 18 metres tall, but suggesting the material would be allowed on shorter blocks unless they were deemed vulnerable to vandalism. The Ministry of Housing, Communities and Local Government (MHCLG) said it would respond to the consultation on extending the ban contained in building regulations “in due course”. Kingspan has told the government that it opposes a ban on specific products and would rather see comprehensive fire-testing of systems, regardless of building height or materials used. Ronnie King, a fire chief for 20 years and now an adviser to the all-party parliamentary fire safety and rescue group, said: “It’s really a no-brainer that you have to protect the school and its fabric. “You would have thought that the lesson of Grenfell was that you protect your assets and lessen the risk of children being injured or, God forbid, killed.” He criticised the current approach of “using materials and construction materials that are almost temporary”. “You save on the construction so it doesn’t matter if they burn down,” he said. “But these are community assets and there is a loss of children’s education when they burn down.” Rockwool, which makes non-combustible insulation, used the construction industry’s Glenigan database to assess the number of buildings with rain-screen cladding systems completed or about to complete since the 2018 ban. It then applied its calculation that combustible insulation has a 75% market share to produce its estimates. “We don’t have a perfect set of information and we are trying to fill the void,” a spokesperson said. “We are trying to demonstrate to government that outside the scope of the ban, buildings are still being built with combustible materials. The number of projects with combustible materials on them is likely to be much higher because there are buildings with non-combustible insulation, but with combustible cladding.” A spokesperson for MHCLG said: “We have already banned the use of all combustible materials on all high-rise flats and hospitals and student accommodation over 18 metres. On lower-rise buildings, all materials must pass tough safety checks before they can be used on a building and our building safety bill will ensure even more stringent oversight of products that are used on homes in future.”