Bucks consulting firm warns more RAAC buildings could be at risk of collapse

A structural engineering firm in Wendover raised concerns over other RAAC buildings not yet flagged which could soon cave in.

Concrete
Author: Zoe Head-ThomasPublished 5th Sep 2023

Since the list of school buildings at risk of collapse due to the unsafe nature of RAAC, concerns have been raised over the structural state of other buildings made out of the same material.

The reinforced autoclaved aerated concrete, commonly known as RAAC, has forced over 100 schools to fully or partially close around the country since the Department for Education made the issue known late last week.

Although regular surveys are being carried out on buildings made of RAAC, this sudden situation put the dangerous nature of the material and the urgency of securing it in the spotlight.

Robert Wallbank, a senior partner at RWA Consulting, a firm which evaluates the safety of buildings in Buckinghamshire, said: "School buildings is where we've been looking at it for the last ten years."

"We're aware of the ones that have RAAC and have been monitoring those over that period."

RAAC was made popular in the 1950s, and was used throughout the following decades, up until the 1990s.

Since then, regular checks have been made to evaluate the safety of buildings made out of it.

"...it could be a winter situation where the collapses are taking place"

Mr Wallbank explained that the concrete differs from the traditional form in that it has a more open structure with more air voids, which allows it to be much lighter and easier to manipulate, but unfortunately proved less robust.

Over time, the typical damage registered is caused by humidity, which can raise concerns over wetter and colder months to come.

Mr Wallbank said: "Whenever it rains, puddles of water accumulate, which is heavy and causes it to deflect a bit more. It's a progressive situation."

"Snow load is another killer of it. The weight of snow can be catastrophic and it could be a winter situation where the collapses are taking place", he added.

In Buckinghamshire, one establishment so far was deemed at risk of collapse and was forced to partially close.

The DfE reached out to Waddesdon High School last week informing them that the start of term will be different than anticipated.

Head Teacher of Waddesdon, Matthew Abbott, said: "It goes without saying that this is extremely regrettable, especially so close to the start of a new school year, but that ultimately, the safety of the school community has to take priority."

"It is of course our highest priority to find alternative arrangements that keep any disruption to learning and the normality of school life to an absolute minimum.”

In response to the news, Buckinghamshire Council said it would support the school affected, alongside any other establishment which could find itself in a precarious situation.

Anita Cranmer, Buckinghamshire Council’s Cabinet Member for Education and Children’s Services, said: “We have been working hard to ascertain the impact on Buckinghamshire schools since this news broke and are still in the process of building up a full and final picture."

Schools in the neighbouring county of Hertfordshire are yet to be surveyed.