The Government's announcement that a number of schools across England would have to close because of Reinforced Autoclaved Aerated Concrete (RAAC) couldn't have come at a worse time – just days before the start of the new school year. Perhaps more worryingly, though, is that this issue isn't contained to the education sector alone, with buildings right across estates now part of the story.

RAAC was commonly used between the 1950s and the 1990s as a cheaper alternative to concrete. But with the cheaper cost comes the drawback that this more lightweight, ‘bubbly' concrete is far weaker and less hardy than the original product. It also has a relatively short lifespan – estimated to be around 40 years.