Reinforced Aerated Autoclaved Concrete (RAAC)

Does the council have any public buildings with RAAC?

We are currently undertaking a survey across our entire property estate to identify the presence of Reinforced Aerated Autoclaved Concrete (RAAC). At this time it has been identified in three buildings and in line with guidance, precautionary works have been carried out.

What are the buildings?

One school, one community centre and one concert venue/theatre.

What is RAAC and why is it used in buildings?

Reinforced autoclaved aerated concrete (RAAC) is a lightweight construction material that was used in the construction of some public buildings like schools and hospitals between the 1950s and 1990s. It was used mostly in flat roofing, but also in some pitched roofs, floors and walls.

It was quicker to produce, easier to install, and cheaper than standard concrete. Despite its name, it is very different to traditional concrete although it looks similar. It is aerated, or ‘bubbly’, and is therefore less durable than traditional concrete.

Why is there a risk?

RAAC can be susceptible to failure when exposed to moisture. The ‘bubbles’ can allow water to enter the material. This moisture can also cause decay in any reinforcement steel (‘rebar’) present in the material.

In February 2022, a report was published by Institute of Structural Engineers RAAC Group following an incident in England in 2018 and an initial safety alert in 2019. Guidance was published by the group in April 2023.

What steps has the council taken?

Following the publication of the Institute’s guidance, the council proactively engaged the services of an external specialist structural engineer to survey the council’s properties. To date, more than 400 properties have been surveyed covering schools, corporate buildings and community facilities. All schools have been inspected, with surveys of a very small number of other buildings to be completed in the coming weeks. RAAC was identified in three: Ravenswood Primary School in Cumbernauld, Pivot Community Facility in Moodiesburn (the centre will be closed for five days from Monday 11 September 2023 for additional works to be carried out) and Motherwell Concert Hall and Theatre. 

In the school and community facility, remedial action has already been taken to ensure the safety of these buildings. This has included the installation of permanent steel supports and other measures as appropriate. The structural engineers have advised us that there are no immediate safety concerns and regular surveys will continue in the meantime.

An initial survey has been carried out on the Motherwell Concert Hall and Theatre which has found that the majority of the roof contains RAAC. The inspection has also found evidence of water ingress to the roof space and a full intrusive survey has been carried out. The concert hall and theatre remains closed to staff and visitors with immediate effect. 

Ticket holder information can be found here. 

The civic centre which is part of the complex remains open. A survey was carried on both the civic centre and civic square buildings and no evidence of RAAC was found.

What happens next?

Permanent solutions for the school and community centre are being designed with a view to works being undertaken in 2024.

As outlined above, a full intrusive survey has been carried out at Motherwell Concert Hall and Theatre and both venues are closed with immediate effect until further notice. While this is disappointing, the safety of staff and visitors to the concert hall and theatre is a priority.

The work to inspect Motherwell Concert Hall and Theatre is complete and we anticipate a report from the specialist structural engineer within the next fortnight. That report will then require detailed consideration before we determine next steps.

To provide certainty for acts and audiences, we have taken the regrettable decision to cancel all performances in the concert hall and theatre up to the end of October 2023.

Ticketholders will be contacted directly by the team at the concert hall and theatre and we will make further announcements when we have received and considered the report.

As is normal practice, our regular survey works continue across the remaining estate and will be part of an annual monitoring inspection by independent engineers.

While all pertinent professional guidance has been followed to date, we will continue to ensure we comply with any further guidance coming from government or relevant professional bodies.

Is council housing affected?

Initial desktop analysis leads us to believe that up to 400 properties may have RAAC as part of their construction. We are in the process of instructing specialist surveyors to carry out inspections and we will liaise directly with tenants in properties requiring inspection.

Are private and commercial buildings affected?

The Institution of Structural Engineering advises that any private owner with properties constructed between the mid-1950s and mid-1990s should conduct a survey of the building to identify or eliminate the possibility of RAAC within the fabric where necessary and assess whether remedial work is required.