Officials at Hertfordshire County Council (HCC) are being urged to complete surveys on up to 100 school buildings in Hertfordshire with "maximum urgency", amid mounting concerns around the safety of a "concrete" that can be prone to collapse.

The surveys will identify whether or not reinforced autoclaved aerated concrete (RAAC) was used in the construction of the schools.

And they come after government officials said that any school or college known to have the material should not remain open, unless "mitigations" are in place.

RAAC is a lightweight material that is known to have been used in the construction of schools and other public buildings between the 1950s and 1990s.

But it is weaker than traditional concrete and there are concerns that it can be prone to collapse.

Previous surveys for RAAC by HCC focused on schools built between 1959 and 1989.

But the latest surveys – on the direction of the Department for Education – will focus on schools built between 1950 and 1958 and between 1990 and 1995.

County council officers have already started to contact schools that have been earmarked for survey, and on-site surveys by specialist contractors are expected to begin within two weeks.

Initially it was thought that 120 Hertfordshire schools would need to be surveyed, in line with government guidance. But it is understood that revised estimates now suggest that fewer will be surveyed.

Cllr Mark Watkin, Liberal Democrat spokesperson for education, stresses that the surveys should be conducted with "maximum urgency".

And he told the Local Democracy Reporting Service: “I think urgency is now critical to get these surveys done – and one can only hope that based on previous surveys the results will not be too disruptive.”

Meanwhile, Cllr Nigel Bell, leader of the council’s Labour group, said that this was an "urgent issue", with a need for the surveys to be completed as quickly as possible.

And he said the council should now publish a list of schools in Hertfordshire where these surveys will be undertaken.

“Parents are going to be feeling really worried – and parents have enough to worry about when their children are starting a new school year,” said Cllr Bell, who raised the issue with council officers in June.

“They need reassurance that Hertfordshire County Council officers are getting on to this quickly.

“I think [the council] should get on with the surveys as quickly as possible.”

Officers from the county council are already contacting the schools that need the surveys and will be encouraging them to update parents directly.

If a survey finds RAAC within a school building that area of the school would need to be closed until remediation work had taken place.

Previous surveys of 279 Hertfordshire schools identified three with RAAC that were in need of remedial work.

And, according to the council, that remedial work was completed in 2022.

Academies and voluntary aided schools will be responsible for their own surveys and any subsequent remedial work.

But council officials say they will work with the DfE "to support them as necessary".

In an updated statement that was issued on Friday afternoon, a spokesperson for HCC said that there was no reason to believe any other of the council’s school buildings contain RAAC.

It states: “Hertfordshire County Council is not aware of any Hertfordshire schools needing to close as a result of the direction from the Department for Education (DfE) on managing Reinforced Autoclaved Aerated Concrete (RAAC) in schools.

“Between 2020 and 2021, we carried out surveys on 279 local authority maintained schools that had buildings constructed between 1959 and 1989, the risk period initially identified by the DfE.

“This identified three schools that needed remediation works, and those works were completed in 2022.

“While we have no reason to believe that any other school buildings contain RAAC, as a precaution we will now also be carrying out surveys on schools with buildings built in the 1950s and early 90s, which are at lower risk.

“We are encouraging parents to contact their school directly if they have any concerns.”

Officials from the Department for Education issued the latest guidance on Thursday (August 31), just days before the start of the autumn term.

They say they were taking the "precautionary and proactive" step following careful analysis on "new cases".

In response to the timing of the government’s announcement, Liberal Democrat Cllr Watkin told the Local Democracy Reporting Service: “I am absolutely appalled that so late in the day this news has broken – and disrupted the lives of schools, families and children.

“Why did they wait until the end of the summer holidays – when it could have been done six or eight weeks ago?”

And Cllr Bell said there were questions to be asked about the "terrible timing" of the government’s announcement – coming just days before the start of the new autumn term.