More than a hundred schools in England were told just days out from the start of term they would have to stay closed because of the type of concrete their buildings were made from. Why? Reinforced autoclaved aerated concrete – or Raac (pronounced “rack”) – is a lightweight, cheaper, quicker to produce concrete that was popular for building flat roofing from the 50s to the 90s.The problem: it’s life span was limited – 30 years limited to be precise and that countdown clock is fast ticking down. The Health and Safety Executive have said Raac is now beyond its lifespan and may “collapse with little or no notice”. The government has known about the potential problems of Raac since 1994 under Labour – and the Conservatives have been monitoring the situation since 2018. Then this summer, a Raac beam collapsed in a school, a beam previously thought of as low risk. Cue school closures. But as Isabel Hardman writes in the Spectator this morning, “everyone saw this coming”. Not helped by former permanent secretary to the Department for Education Jonathan Slater telling the BBC this morning that in 2021 then-chancellor Rishi Sunak slashed the number of schools in the suggested school rebuilding plan. The other problem: asbestos, which may also be present in schools that have Raac structures.