Shockwaves have been felt across the education sector following severe concerns raised about the use of reinforced autoclaved aerated concrete (RAAC) in school buildings.
This issue dates back to 2018 when a roof collapsed over the weekend at a school in Kent. RAAC was flagged as a safety risk, starting an investigation and the formation of a Standing Committee that issued a report in May 2019 on structural safety that highlighted significant risk of failure of this substance.
In September 2022, the Office of Government Property issued a safety briefing notice to all property leaders regarding RAAC, resulting in an investigation in which over 150 educational buildings and several hospital sites were identified as containing the potentially defective concrete. According to the National Audit Office, RAAC has been identified in 572 schools out of 21,600 examined.
RAAC is a lightweight form of concrete developed by a combination of cement, lime, water and an aeration agent. It was used predominantly in the 1950s to the 1990s. The mixture is poured into moulds and then subjected to high pressure and heat, known as autoclaving, to create a lightweight, strong, and porous material. Consequently, there is a risk that the aerated and bubbly concrete contains no coarse aggregates and is, therefore, less dense than traditional concrete, allowing for performance defects, manufacturing defects, and construction defects to become apparent over time.
It is essential that those responsible for the management, maintenance and alterations of buildings know whether or not their buildings contain RAAC. If they do not know, they should seek urgent expert advice.
If a property containing RAAC has not been managed correctly and regularly, then it leads to a greater risk of failure of RAAC building components that could also be too old for continued use and liable to collapse.
The Department for Education (DfE) has established dedicated caseworkers for premises with confirmed presence of RAAC, stating that the Government has been aware of public sector buildings with RAAC since 1994. Where confirmed, capital funding for essential works to remove any immediate risks and potentially provide for temporary buildings has been announced. "Rapid" support, in the form of funding for surveys, is available according to the DfE for all but independent schools, subject to the advice of structural engineers and this will be funded by them. The school should then also benefit in the longer term to the School Rebuilding Programme.
Whilst the funding will not be available to independent schools, the reports issued by the Standing Committee and the Institution of Structural Engineers are essential reads. Buildings insurance policies should be reviewed, although we consider it unlikely that a latent defect such as this, which formed an original construction project many decades ago, would be actionable.
We recommend all education institutions conduct investigations of their estate and (where applicable) notify the DfE using its questionnaire. These investigations to remedy or mitigate the health and safety issues should include:
1. an initial examination of your asbestos register and management plan;
2. a review and undertaking of visual inspections and crack defects monitoring;
3. a review of existing surveys (suspected RAAC will be brought forward for further surveys if identified through the DfE questionnaire);
4. non-destructive testing to note the presence of asbestos in these buildings; and
5. intrusive surveys to examine panel bearings and identify any corrosion.
According to the Institution of Structural Engineers' RAAC Inspection and Assessment Report issued in February 2022, once you establish the condition surveys a structural engineer may need to recommend further monitoring, remediation strengthening or replacement of RAAC panels. This could include emergency propping, enhanced end bearing to mitigate against known deficiencies, removal of individual panels, and replacement of them with an alternative lightweight solution, or even an entire roof replacement.
Repairs need careful consideration as mortars commonly used today may be stronger and denser than RAAC, meaning they may not be able to generate sufficient bonding to remain in place. This could create further risks where there may be asbestos within any original surface coating.
As not all defects are visible, and records regarding construction and installation are frequently lacking, the Government has ordered the closure of hundreds of schools to address the immediate risk to harm that the RAAC crisis poses, pending each building being properly surveyed. This issue is not limited to public buildings, and all educational institutions should be reviewing their estates and assessing the risk.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.