Insight
RAAC remedies: How to achieve unification on an educational crisis
28 Jan 2025

William Phillips
National Discipline Director
Persisting and problematic has been the theme surrounding reinforced autoclaved aerated concrete (RAAC), with structural performance issues cited as far back as the 1980s. Four decades later, Britain’s schools are crumbling, according to government reports that highlight the hidden dangers of collapse and the very real risk to life.
Having both worked on RAAC remediation schemes, here, our national discipline director, William Phillips and Steve McSorley, director at civil and structural engineering consultancy, Perega, discuss how best to remedy the issues at work in education, and what needs to be achieved to help solve a nationwide problem.
In the 2024 Autumn Budget, it was announced that £1.4bn would go towards rebuilding 50 schools in England each year. The decision was set against a backdrop of delays to the government’s School Rebuilding Programme, formed in part as a response to the dangers of RAAC, as well as a general ‘deterioration’ of the overall education sector estate spanning several decades.
In the same month, it was cited that only 23 out of more than 500 schools had completed repair works.
These figures - and RAAC’s impact on them - call into question a central issue plaguing the overall school estate: governance and accountability, with many of today’s issues cited as coming from a lack of early intervention over a period of more than 40 years.
William said: “There’s a lot still unknown, particularly with RAAC. With the delays, the longer schools are left in uncertainty, the worse the problem will be, not just structurally but financially too.”
Indeed, RAAC is a prime example of early detection, minimal intervention, with production of the material ceasing in 1982
due to concerns over its longevity. While the government has known of compromised RAAC in public sector buildings since 1994, it wasn’t until 2018 that the situation became more widely monitored.
Industry officials and governments have made more stringent measures to remedy RAAC risks, encouraged in part by the media focus on the matter since 2022, but perhaps to the cost of several high-profile cases, including in 2018, when a ceiling collapsed at Singlewell Primary School in Gravesend.
Hindsight always gives 20:20 vision of what’s come before, “If this had been acted on 10-15 years ago, it would cost a lot less, and in more ways than one,” said William, but as consultants in the sector, it is our responsibility to work with the tools available to help alleviate the issues faced today. In this case, that means building records, visual inspections and risk monitoring systems.
“We must look at each specific case, develop a survey and come up with an immediate action plan,” added William, implementing remediation works as quickly as possible to ensure a safe sector and environment for pupils and staff.
Setting a remedy
Following a traffic light system, with red being for the most persistent and immediate dangers to fix, we often find the real crux of issues for clients to be at the more amber-led and below level. Red is of course the priority, with government intervention helping to address the most serious of cases, but dropping down a level, there is the complex interplay of funding and remediation choices, where the option to rebuild or replace is not quite as clear cut.
Steve said: “Quite often with RAAC, you can’t fix things straightaway. The most important part to it is to stabilise the bearings and remove the risk of instantaneous collapse.
“The real crux though, is what you do over the course of the next 6-12 months – do you monitor for any deflections as standard, or do something now to strengthen and remove?
“That can come down to each individual case and expertise, but also a lot of client-led discussion, particularly if they aren’t receiving government support.”
Inflation continues to fluctuate, and construction’s persistent issues around material costs and supply chain constraints only exacerbate the feeling that RAAC is a very costly issue to fix for the education providers and local authorities bearing the weight of responsibility.
Where rebuilding is an option for clients, particularly with government funding, there is the significant advantage that schools are constructed with more stable and load bearing materials, thus eliminating the worry around an outdated material ever posing a risk to life ever again.
With a net zero hat on, just how much carbon this emits per project is perhaps something that weighs heavily on the minds of stakeholders, particularly with stringent environmental targets to hit across regional authorities.
Steve said: “What we need is a centralised set of guiding principles and direction on the right remediation techniques for the less immediate (amber) projects.
“There is more of a grey area here in the argument to rebuild or replace, which often comes down to cost. There is no central voice stating: are we going for the gold standard, unless it’s untenable?”
So far, education has been unified the most by design, particularly given the prominence it has gained in the national media, owed in part to the dangers it places on large numbers of young pupils. While each case of RAAC has its nuances, in most cases any deflections or bending of materials is seeing schools receive significant structural strengthening and/or structural replacement with more durable materials.
A real concern remains in the private sector, where there is so far less focus on remediation of things like hotels, offices, retail and commercial buildings.
Steve said: “There’s a lack of government funding or focus here, which means there is a very real danger that RAAC could escalate into the next big crisis. I’ve worked on a lot of commercial buildings where there are cases of water penetration causing severe issues, as well as the less immediate dangers that RAAC poses.”
Contractors, engineers and consultants may be carrying out valuable work in the private sector, but they are also operating somewhat in silos, without a centralised guide map to help inform their decision making.
At present, there is less funding being committed to these areas, so Steve says stabilisation methods to remedy RAAC may be just as advisable as looking to costly rebuilds.
“This technique means you’re utilising steel and / or timber to support the weight of the planks and the stress out of the RAAC material. It can provide clients with an immediate solution to their needs, making the structure safe with lower levels of disruption and without breaking the bank. It’s still important however, to assess on a case-by case basis to ensure the solution is suitable.”
As history demonstrates, education was unified sadly, by several prominent collapses before a firm government action plan was drawn, but this shouldn’t carry forth into a potential hidden danger in the private sector.
Safety first
Building safety has come a long way in the past 30 years, which is clear to see by the stringent measures now being implemented with the Building Safety Act.
“Successive governments are making more responsible and responsive moves to ensure our built environment is constructed to the highest of standards,” said William, “with a conscious health and safety-first approach.”
However, there is still more work to be done. What was deemed safe 40 years ago should always be subject to constant evaluation.
While new construction techniques are often lauded because of their efficiencies over past methods – like today’s focus on modular – mistakes can be made. In August last year, the DfE reported a number of workmanship and safety issues at modular schools built by Caledonian Modular, leading to their closure.
“These may be isolated cases, but it’s very easy to see how one bad practice can pass to another, and set in motion the wheels of a crisis,” added Steve.
To achieve better together, we must collaborate across the board, connecting public and private sectors, as well contractor, engineer, consultant and government sectors.
“There’s already some fantastic work being done out there, including a RAAC research group at Loughborough University, and a study group under the Institute of Structural Engineers,” said William.
“With both the DfE and NHS England offering informative advice online, it means we must absorb and develop our skills and practices as much as we can to successfully stem the RAAC crisis together.”
Only by undertaking such practices can we ensure that building safety remains a pre-emptive, rather than post action response.

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