Skip to main content

Reinforced Aerated Autoclaved Concrete (RAAC)

Frequently asked questions about 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 four buildings and in line with guidance, precautionary works have been carried out.

What are the buildings?

Two schools, 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 The Institution 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 Institution’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 being completed.

RAAC was identified in four: Ravenswood Primary School in Cumbernauld, the extension at Caldervale High School in Airdrie, Pivot Community Facility in Moodiesburn and Motherwell Concert Hall and Theatre.

Ravenswood Primary School, Cumbernauld 

In Ravenswood Primary School, remedial action has already been taken to ensure safety. 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.

The council decided at a meeting of Policy and Strategy on 5 December 2024, to replace the roof of the school. To carry out the work safely, it will be necessary to move the pupils and staff of Ravenswood on a temporary basis to the nearby St Mary’s Primary School. The staff of both schools are working extremely hard to create a welcoming environment at St Mary’s for Ravenswood pupils which offers the opportunity for shared facilities, collaborative learning and making new friendships. We are in direct contact with parents and carers as planning for the temporary move progresses.

Pivot Community Facility

While remedial action had previously been carried out at the Pivot Community Facility in Moodiesburn, during the most recent inspection by external specialists it was identified there has been potential deterioration of areas of RAAC in the centre, including to the reinforcement steel contained within the RAAC planks. The council has decided to replace the roof area affected and planning is underway for this programme of work. The Pivot Centre is currently closed until this work is carried out.  

The majority of groups and people who had bookings for the centre have been moved to alternative provision. There is no RAAC present in the library and this will remain open. However, this will remain under review depending on what access may be required for any works or maintenance.

Caldervale High School Extension

A small amount of RAAC has been identified in an area of the extension to the rear of Caldervale High School. This separate extension is not used by pupils or staff and we have decided to demolish this section of the building. Works will be designed to minimise disruption to the school community. 

RAAC is not present in the main building of the school.

Motherwell Theatre and Concert Hall

As part of our inspection of the Motherwell Theatre and Concert Hall complex in September 2023, RAAC was identified in 95 per cent of the roof area. A number of the RAAC panels showed damage including signs of water ingress that could weaken the load-bearing capacity of the roof.

The building has been closed since this date on safety grounds, with most of the programmed shows and performances relocated to Airdrie Town Hall, Ravenscraig Regional Sports Facility and other venues.

We have explored all the options and have concluded that removal of the RAAC and replacing the roof would cost a minimum of between £10.5 and £11.65million and likely considerably more.

The concert hall and theatre have played a huge role in the cultural life of Motherwell and North Lanarkshire as a whole over many years. However, the only economically viable option is to demolish the theatre and concert hall, which has been an incredibly difficult decision. Culture has a huge part to play in people’s lives and that is why we have agreed that options will be considered in the future to include cultural facilities as part of the approved Ravenscraig Hub.

In the meantime, we will continue to use the excellent facilities at Airdrie Town Hall to programme as many shows as possible and the hugely popular pantomime will continue to have a home at Ravenscraig.

We continue to work with promoters to relocate other shows to another venue.

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?

Planning is underway for the relevant works improvement works at Ravenswood Primary School and The Pivot Centre, and for the demolition works at the extension to Caldervale High School and the Motherwell Concert Hall and Theatre as outlined above. 

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?

An initial desktop analysis identified that up to 400 properties could potentially have RAAC as part of their construction. A further more detailed analysis has revealed the figure to be 22 properties which may have had RAAC used as part of their construction. This assessment is ongoing and includes inspections and checks with our appointed independent specialist surveyors and structural engineers and direct liaison with any affected tenants.

Through checking records and a confirmation survey on the date of the assessment by an independent structural engineer, we have identified that RAAC is present in the construction of the roof of four blocks of flats in Bellshill and Wishaw and twelve blocks of flats in Bellshill. Remedial works have been carried out in the common area of five of the blocks of flats in Bellshill and an intrusive survey is required to assess the present condition of the RAAC in the roof area in the blocks of flats in the Wishaw area. This will require tenants on the top-floor to move into alternative accommodation while the intrusive survey is carried out to assess the present condition of the RAAC. Housing officers and technical officers have been liaising directly with affected tenants to provide support.

Are private and commercial buildings affected?

The Institution of Structural Engineers advises that if an owner or manager has a building or property constructed between the mid-1950s and mid-1990s and is unsure of the form of construction, they should carry out an inspection and a risk assessment. This will help to identify or eliminate the possibility of RAAC within the fabric where necessary. 

If RAAC planks are present, their structural condition will need to be determined by a Chartered or Incorporated Structural Engineer. 

Subject to the Chartered or Incorporated Structural Engineer’s findings, a process of ongoing monitoring and/or remedial propping or strengthening works may be needed. In some instances, it may be necessary to remove or replace RAAC planks

Further information can be found on its website

Page last updated:
09 Dec 2024

Help us improve this pageClose

We're sorry this page didn't meet your expectations this time. Please let us know if you have any feedback to help us improve the content.

If you have a question or comment about a council service or would like a reply, please contact us.

Thank you for your feedback