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 limited durability of RAAC roofs and other RAAC structures has long been recognised; however recent experience (which includes two roof failures with little or no warning) suggests the problem may be more serious than previously appreciated and that many building owners are not aware that it is present in their property.
Following tests carried out by the Building Research Establishment, it was thought that RAAC planks gave adequate warning through visual deterioration before failing. However, the two recent failures show this can no longer be relied upon.
Redmond & Associates have experience in surveying buildings for the presence of RAAC and can advise on its condition and repair/replacement.