Reinforced autoclaved aerated concrete (RAAC) was used in the construction of numerous buildings in the 1950s and '60s, but the building material - which has been described as being full of air holes 'like an aero' - has since been found to be at risk of crumbling.
Concerns over the potential for building collapse have prompted the widespread closure of affected schools, and housing consultancy firm Rapleys has called for an urgent investigation into social housing to establish whether the material is posing a risk to residents.
Birmingham officer Richard Crow told Inside Housing: “There is no way to say which properties have RAAC other than to inspect properties containing flat roofs, built during the 50s, 60s and 70s.
“During this period, the largest number of social housing was built so it will be a case of urgent thorough inspection across the country by local authorities, and then, for those that do have it (our figures of 5-10% were based on the investigations we are working on within schools), putting in place the solutions to ensure they are protected against damage.”
The building material is still used in construction today, however the method in which it is used differs from the way it was used during the 1950s and '60s, Crow said, which is why school closure relate to buildings that were constructed with RAAC during that time.
Schools minister Nick Gibb told BBC Breakfast on Friday that the government was looking into other public buildings that could be affected by the concrete, with all departments having been instructed in June this year to investigate the risks of the lightweight concrete.
“Right across the public sector, we are surveying the estate," he said.
“You’ve heard of a court closing at Harrow. We are taking action, of course, in the hospital sector as well.
“Hospitals are very large buildings and they have teams of very expert maintenance people monitoring the building the whole time.
“They use propping where they identify RAAC and also we are rebuilding seven hospitals because of extensive RAAC in those hospitals.”
And while the government's property portfolio was worth £158bn as of March 2021, much of the property it dd own has been sold to private owners - who will now assume responsibility for any necessary repairs to make RAAC buildings safe.
The Local Government Association told the trade publication 'Building' that the issue “may be more serious than previously appreciated and … many building owners are not aware that it is present in their property”.