After UK schools were given one working day’s notice to close due to the risk posed by RAAC panels, the construction industry responds
Despite being aware of the structural risks of RAAC panels since the 1980’s, over a hundred schools in England were told to close last week– meaning many pupils will have to wait to return to their classrooms.
The issue resurfaced in recent years after a 2018 roof collapse in an Essex school and the government scheduling seven hospitals to be demolished and rebuilt.
Colin Tait, civil and structural director at Harley Haddow, said: “It is surprising that this has suddenly become an issue, as the failure mechanisms of RAAC panels have long been discussed and on the radar of structural engineers. Across the UK, RAAC panels are present in a large number of buildings from police stations through to schools and hospitals. A collapse of these planks could be catastrophic, which is why we are seeing such rapid action being taken.
“From the mid-90’s, the UK’s Building Research Establishment was publishing information guides on RAAC identification, potential failure modes, maintenance regimes and remedial works – this was all off the back of RAAC failures in the 80’s.
“As recently as 2019, warnings by the UK’s SCOSS (Standing Committee for Structural Safety) of a RAAC panel collapse in a school brought a renewed light to the subject. Respective government bodies made building owners aware of these potential risks at that time.
The aerated texture of RAAC panels lead to swifter deterioration
“There are many reasons why these planks fail. Overloading, poor or limited plank support, excessive deflection and water ingress to name a few. Some of these flaws are down to poor design, poor construction, or simply down to poor maintenance. Cracking to the plank, particularly near its support and water ingress – whereby it turns the concrete, in essence, to a ‘sponge’ – were felt particularly worrying. Hidden behind false ceilings, collapse of these planks could be without warning and devastating.
“Presently the Department for Education August 2023 guidance advises restriction of access to spaces where RAAC has been confirmed. This is irrespective of the condition, the maintenance programme or inspection regime previously implemented.”
If your building may be at risk, contact a surveyor or structural engineer
Tim Seal, head of construction at law firm Ridgemont, says:
“The impact of RAAC will vary case-by-case. Not all schools with RAAC need to close: the disruption experienced will depend on a case-by-case basis including what mitigations a school can put in place – and how quickly it can do so.
“The government has been managing the risks associated with RAAC since around 2018 by providing guidance (and funding) for owners and managers. However, some recent cases – including sudden roof failures – have caused it to decide that buildings containing RAAC should not stay open without extra safety measures being put in place. This can be considered as part of Government’s policy emphasis over the last few years on the safety of buildings, especially those occupied by more vulnerable parts of society.
Hospitals, shopping centres and prisons may also contain RAAC
“RAAC was used from the 1960s to the 1990s in various types of public buildings – not just in schools, in hospitals for example. Not all remain in the public sector today. It would be sensible for building owners and managers at risk of having RAAC in their buildings to contact a qualified structural engineer or building surveyor for advice.”
