RAAC: How to spot it and what to do next

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Lucia Glynn


Lucia Glynn


Capability , Future Thinking
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With the recent news that more than 100 schools and colleges are to partially or fully close buildings after the unsafe material, Reinforced Autoclaved Aerated Concrete (RAAC) was found in ceilings, the spotlight has firmly been placed on at risk buildings and what can be done to support them. It should be noted that RAAC does not just affect the education portfolio, but can be found across the wider public estate. RLB has experience in supporting clients through the challenges of RAAC over several building types and sectors across the public estate, including education.

In this article that first appeared in Schools Week in June, RLB Partner Lucia Glynn, highlighted the challenges and what can be done to address what’s been labelled a ‘ticking timebomb’ for school buildings across the country.

This article was first published in Schools Week in June 2023.

Even without this developing crisis, the safety of schools and the maintenance of an ageing educational estate continue to be major challenges that are rarely out of the spotlight.

In the past few weeks, questions have been raised about when information from the condition survey will finally be released, and we have had the announcement of the latest round of successful projects from the squeezed Condition Improvement Fund (CIF). This sits alongside the ongoing challenge of rising costs for managing repairs.

Funding, as ever, remains one of the largest uncertainties. For many schools, the unknowns relating to RAAC (whether they have it, and what they then may need to do) add a layer of complexity.

We understand that the commission set up by the DfE to help schools with RAAC is currently considering options around how funding for this essential remedial work could be managed.

In the meantime, if you suspect your school (or an extension or alteration) may have been built using RAAC, there are a few initial steps you can take to confirm that.

How to spot RAAC

First, RAAC was typically used from the 1960s to the 1980s, so any buildings constructed outside of this time frame can be discounted. Then, if construction drawings are available, these can be really useful in identifying how the school was built and the materials used. Previous Condition Data Collection (CDC) surveys may also provide information on whether RAAC is present.

If your building was built within that time frame, the next step is a visual inspection. This may involve high-level access (ladder or scaffolding) and opening-up works to reveal the building structure. Buildings constructed in the relevant time frame are also likely to contain asbestos, so review the asbestos register or undertake a survey prior to inspection if no information is available.

RAAC is typically found in the form of planks, around 450 to 600mm wide and around 2.4 to 3m long, with a chamfered edge detail. The ‘concrete’ has an aerated, ‘bubbly’ texture and is softer than typical concrete, which may be able to be indented with a sharp tool such as a screwdriver. Typical defects include mass hairline cracking and deflection of the planks between the structural supports.

If you believe that RAAC is in place, further investigation will be required in the form of sampling for lab analysis and the appointment of a structural engineer. It would also be worthwhile considering putting in place planned preventative maintenance given the susceptibility of the material to water damage.

What next?

The government has just ordered all departments to investigate whether RAAC is an issue in their related estates. Clearly, the magnitude of the problem and the size of the pot required to address it are a pressing issue for ministers, and it is likely that any solution will have repercussions for other funding. 

We already know that an estimated £11.4 billion is needed to repair the schools’ estate. The work required to address RAAC will only add to that. With a finite amount of money available for investment from the treasury, it will be interesting to see how this is managed and if it leads to a decrease in size of the Condition Improvement Fund going forward.

We’ve already seen this pot squeezed from an initial £498 million down to £456 million in the past year, with 25 per cent fewer projects being awarded. It seems likely that this could be tightened further.

School budgets themselves are tight, and without local authority support it’s likely the process of identifying RAAC will come at a cost. However, it’s a really prudent investment that will not only save money in the long term, but could eventually save something far more valuable than that.