In recent months, Reinforced Autoclaved Aerated Concrete (RAAC) has become a focal point of national concern. Used in school buildings for decades, its deteriorating condition has raised safety alarms, resulting in the temporary or permanent closure of many educational facilities.
In this article we will cover the current guidance from RICS on what to do if you suspect your property contains RAAC and outline the ways we can assist you with professional structural surveys.
RAAC Explained: What You Need to Know
Reinforced Autoclaved Aerated Concrete (RAAC) is a lightweight, precast material used extensively in construction from the 1950s through the 1990s. It was typically installed in flat roofing systems, as well as select wall and floor panels. Its affordability and ease of installation led to widespread adoption across institutional and commercial buildings, with minimal application in residential housing.
The visible bubbles in RAAC indicate its open texture, which allows water to seep in more readily than standard concrete. This is especially problematic when steel reinforcement is involved, increasing the risk of corrosion and structural failure.
RAAC’s affordability and light weight came at the cost of durability, and it was never designed for long-term use. Despite earlier assessments, some schools classified as safe suffered damage or near-collapse in recent months, leading to sudden closures. As a result, attention is now turning to other buildings, although early indications suggest few private sector properties are affected.
Steps to Take If You Suspect RAAC in Your Building.
If you are unsure whether RAAC is present in your property and lack the necessary documentation, RICS advises against conducting any inspection yourself. Instead, you should contact a structural engineer or an independent chartered surveyor for a proper assessment.
RICS is already helping the Department for Education tackle the RAAC issue in schools. They are also supporting efforts in hospitals and other public buildings, many of which are being checked or are already undergoing safety improvements.
A structural engineer or surveyor will be able to confirm the presence and scope of RAAC in your property and guide you on the best course of action. Where needed, they can also assist in setting up a Planned Preventative Maintenance schedule to help protect the building over time.
How Much Time Will It Take to Fix?
To ensure safety in the short term, your surveyor or engineer may recommend temporary measures like installing roof supports. More lasting solutions, such as completely replacing affected structures, will take longer to carry out.
It is important to consider that some structural repairs such as the replacement of a flat roof with a more conventional alternative may require planning consent. Projects in areas with heavy usage or permanent occupancy may lead to significant disruption, necessitating alternative routes or temporary relocation of staff and services. However, the effect is likely to be far less disruptive if RAAC is present in a non-critical or infrequently accessed space.