RAAC is a lightweight form of concrete used in roof, floor, cladding and wall construction in the UK from the mid-1950s to the mid-1980. We believe it was used by some municipal architects primarily in office and schools, but RAAC has been found in a wide range of buildings, not all of which are still in the public sector.
The Local Government Association provide some background and advice on checking buildings will roofs, floors, cladding or walls made of Reinforced Autoclaved Aerated Concrete (RAAC).