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RAAC - what is it and why is it unsafe?

Reinforced Autoclaved Aerated Concrete (RAAC) is a lightweight concrete material, used mainly between the 1950s and 1990s as a cheaper alternative to standard concrete. It is most commonly found used as precast roof panels in flat roofs, and occasionally in floors and walls.

Problems with RAAC have been known about since the 1980s, when some structures containing the material were required to be demolished². Its ‘bubbly’ texture and tiny holes throughout makes it much more vulnerable to moisture, which leads to decay, rusting, degradation and eventually, collapse.

The Health and Safety Executive has said that RAAC is now beyond its lifespan, and structures containing the material may collapse with little or no notice³.  Worryingly, thousands of UK public buildings are known to use the defective material, including many schools and hospitals.

Risk to private and commercial property

Though mainly used in the construction of public buildings, it is believed that RAAC planks are present in many types of structures, including those for commercial or private use. The presence of RAAC was found at a shopping centre that was built in the 1970s, prompting a full report.

RAAC planks were commercially available during their period of usage, making it likely that they found their way into structures other than schools and hospitals, however, the full extent to which they were used in private buildings remains unknown. Building surveyors, engineers or any personnel who manage buildings should be aware of RAAC and ensure that appropriate risk management measures are implemented and followed.

Could RAAC affect my building's insurance?

Though it is yet to happen, insurers may soon begin asking policyholders about the presence of RAAC in properties. This information must be treated as a material fact that should be disclosed to insurers, as if it remains undisclosed it is unclear at this time what steps will be taken by insurers and if this will affect your cover. After 1998, no new buildings used RAAC in their construction, meaning that there will be no cover under latent defects policies (as these typically last 10–12 years maximum), and all policies will have expired many years ago.

Most insurance policies are not designed to cover wear and tear of buildings or construction defects, making the issue of RAAC particularly difficult for insurers. If RAAC is present, insurers will likely insist that targeted safety measures are put in place and the structure is monitored on a regular basis to reduce the risk of collapse.

How to find out if your property uses RAAC

In August 2023, the UK Government issued guidance for identifying RAAC components in building structures, particularly for local authorities, academy trusts, governing bodies, schools, colleges and building professionals.

If you suspect RAAC is present within your structure, you should seek guidance from a structural engineer who will then assess it and develop a management plan to ensure that measures are taken to improve building safety.

Before examining suspected RAAC behind ceilings or finishes, you should also ensure that guidance about managing asbestos is consulted beforehand and that you refer to the building’s asbestos register. If in doubt, speak with an asbestos professional.

NFP are a commercial insurance partner you can trust

Do you have concerns about the presence of RAAC potentially affecting your policy? Our commercial insurance specialists are on hand to guide you. NFP’s expertise and access to experienced insurers makes us a partner that you can trust to find the best solutions for you and your business. Find out more in our commercial building insurance section.