We replaced our old felt roofing with Metrotile lightweight steel roofing last year after seeing their education page: https://www.metrotile.co.uk/bu....ilding-types/educati . It’s been a big improvement in both insulation and durability. The installers completed it over the Easter holidays, so no classes were interrupted. Even the council inspectors commented on the neat finish and fire resistance rating. For older buildings, it’s a safe and long-lasting choice.