Reinforced autoclaved aerated concrete (RAAC) is a lightweight building material commonly used from the 1950s until the mid-1990s, with some continued usage believed to have occurred thereafter.

The recent collapse of a beam that had been considered safe has sparked an urgent rethink on whether buildings with aerated concrete can be taken to be safe are now at possible risk of collapse.

This has caused national concern with currently more than 100 schools and colleges across England having been told by the Department for Education to partially or fully close buildings just days before pupils prepare to return after the summer holidays.

Nationally, councils are seeking to organise surveys of schools that are maintained by them that were built between 1930 and 2000.