Britain has a new big problem: crumbling concrete in schools, hospitals, airports, and theaters

• Some buildings in the UK were made with a type of concrete called RAAC that's now unsafe.
• The "crumbly concrete" was used in hundreds of schools and some have been shut over fears of collapses.

More than 100 schools in the UK have been closed because the type of concrete used to build them has become unsafe and means they could collapse.

The announcement was made just as the new school year began and it's caused havoc for many parents and teachers – and ignited a debate about what the government knew, and when.

What's happening?

The UK government said more than 100 schools faced closure because they contained reinforced autoclaved aerated concrete (RAAC), a material typically used in roof planks and wall panels.

"RAAC is now life-expired. It is liable to collapse with little or no notice," the Health and Safety Executive wrote.

The concrete has repeatedly been blamed for roof collapses and has been the subject of several reports warning of the risks. These issues have only become more apparent as the material, mostly constructed some decades ago, has aged.

The decision to close some schools, or stop using certain buildings, comes at the start of a new school year, exacerbating a policy crisis for the UK government.

Most schools have made alternative arrangements such as moving students to other sites, the government said, but nearly 40 have either resorted to pandemic-style remote learning, or delayed the start of their school term altogether.

There are now questions over how many other buildings might be fitted with RAAC, and whether those too might be forced to shut. A report in June by the National Audit Office identified 572 schools with a potential RAAC problem.

Other structures such as hospitals, theaters, universities and some apartment buildings are also being checked for the concrete. Several theaters have partially or fully closed because they contain RAAC, The Guardian reported, forcing productions to shut down.

Heathrow and Gatwick, Britain's two biggest airports, told the Financial Times they had found the concrete in some of their buildings.

Matthew Byatt, president of the Institute of Structural Engineers, told the FT that a building containing RAAC "could be at risk of collapse with little or no warning."

Two of the UK's busiest international airports, Heathrow and Gatwick, told the Financial Times that they had detected the sometimes-fragile concrete on their estates.

The crisis has reignited a debate about "austerity," with the opposition Labour party blaming cost-cutting by the ruling Conservatives for creating a ticking time bomb.

Why is the concrete crumbling?

RAAC is dangerous because its components are vulnerable to water seepage, rusting the reinforcing bars the concrete surrounds and reducing their structural integrity.

When RAAC was used on flat roofs, the danger was more pronounced as water could remain for extended periods after rainfall.

There have long been concerns that these issues would eventually make RAAC building unusable. A collapse in the 1980s was blamed on the concrete and some buildings were subsequently ordered to be demolished.

Way back in 1999, the Standing Committee on Structural Safety published a report advising the inspection of any structures built with RAAC before 1980.

Fresh concerns were raised in 2018 after a school collapsed in Kent.

The Standing Committee published another report in 2019 with a fresh warning about the dangers of RAAC, saying that those made before 1980 were now past their use-by date.

Why was the concrete used?

RAAC became popular in the second half of the 20th century amid a construction boom. Before its dangers became apparent, the material – which originated in Sweden in the 1920s – was seen as a cheaper and easier construction method.

RAAC was particularly popular between the 1960s and 1980s, which Professor Chris Goodier of Loughborough University said was the period of most concern to policymakers.

Unfortunately, this was also when many UK schools were constructed, owing to the baby boom and an increase in the school-leaving age to 15 in 1947, and to 16 in 1972.

According to a survey by the Department for Education (DfE) published in 2021, nearly 10,000 school buildings were constructed in the 1960s, and about 8,000 in the 1970s.

What's being done?

The government is scrambling to take action, but the crisis was a long time in the making.

The Tories took power in 2010 after 13 years of Labour and the financial crisis of 2007/8 with a promise to revive the economy on a policy of aggressive spending cuts labelled austerity.

According to the think-tank the Institute for Government, those cuts are linked with schools' RAAC closures. It estimates that the DfE's capital budget dropped by more than a third between 2007/08 and 2020/21, from £7.9 billion to £5.1 billion.

As part of the cuts, the government scrapped Labour's Building Schools for the Future programme, which might have replaced some of those now affected. Maintenance of school buildings is the responsibility of local councils and academy trusts, but many have also suffered cuts to their funding, further complicating the picture.

In the House of Commons on Wednesday, Labour leader Keir Starmer likened prime minister Rishi Sunak's Tory government to "cowboy builders" over the crisis.

In an article for the The Times of London, NAO chief Gareth Davies also criticized the government's cavalier approach to maintaining schools.

"The underlying challenge is that adequately funding responsible capital programmes for our public services leaves less for higher-profile projects. Failure to bite this bullet leads to poor value, with more money required for emergency measures or a sticking plaster approach," he wrote.

The Education Secretary said the government would fund emergency maintenance measures and longer-term rebuilds where necessary.

What happens now?

Despite making spending cuts over the past decade, the repair bill could be huge.

An estimate by the Financial Times suggested the cost of rebuilding blocks at the 572 affected schools could be just over £3.1 billion ($3.9 billion.)

Some see the crisis as another blow to the UK's standing as a well-run first-world country, and follows ongoing problems with the National Health Service, soaring cost of living and issues connected with the departure from the European Union.

A column in the current issue of the right-leaning political magazine The Spectator is headlined Broken Britain: what went wrong?

While he's in India this weekend for the G20 summit, the crumbly concrete conundrum will still be waiting for Rishi Sunak upon his return.