Concrete surveys are being conducted at 120 schools in Northern Ireland to check for potentially unstable reinforced autoclaved aerated concrete (Raac), according to the
Education Authority. The material, which is used in roof panels, can become "crumbly" over time and has led to the closure of some UK schools. The safety of staff and students is of "paramount importance," the Education Authority said, and the survey results will determine any further action. Investigations into Raac are also under way in Wales, where two schools have closed. Photo by Ardfern, Wikimedia commons.