This building has a reinforced autoclaved aerated concrete roof. > RAAC has been shown to have limited structural reinforcement bar (rebar) integrity in 40 to

This building has a reinforced autoclaved aerated concrete roof. > RAAC has been shown to have limited structural reinforcement bar (rebar) integrity in 40 to 50 year-old RAAC roof panels, which began to be observed in the 1990s.[22][23][24][25][26] The material is liable to fail without visible deterioration or warning.[22][26] The material is not the root cause, rather inadequate roof maintenance, which permits water infiltration, and decisions by building owners as to repair or the replacement of existing roofs, which is a part of cost-benefit analysis.[27] > Professional engineering concern was publicly raised in the United Kingdom in 1995 about the structural performance of RAAC following inspections of cracked units in British school roofs,[28] with it being observed that it was likely that RAAC in other countries may exhibit problems similar to those found in the United Kingdom.[18] https://en.m.wikipedia.org/wiki/Autoclaved_aerated_concrete https://en.m.wikipedia.org/wiki/Autoclaved_aerated_concrete More info about RAAC, specifically from the 1950s-1970s https://www.lboro.ac.uk/news-events/news/2023/march/reinforced-autoclaved-aerated--concrete-raac/ https://www.lboro.ac.uk/news-events/news/2023/march/reinforc...