Information on RAAC – Inverclyde Council

Q&A - Reinforced Aerated Autoclaved Concrete (RAAC)

Does the council have any public buildings with RAAC?

The Council has carried out a comprehensive assessment of its estate to identify the presence of Reinforced Aerated Autoclaved Concrete (RAAC). It has been identified that one school and one office building have RAAC present and in line with guidance, a management strategy has been implemented for each building.

What are the buildings?

St. Michael’s Primary School and Princess House, both in Port Glasgow.

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.

Why is there a risk?

RAAC can be susceptible to failure when exposed to moisture. This moisture can cause decay in any reinforcement steel 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 undertook a review of building condition and asset information and proactively engaged the services of an external specialist structural engineer to assess properties identified with elements of concrete construction. The Council’s full estate has been assessed with RAAC identified in one school, St Michael’s Primary School in Port Glasgow, and one office, Princess House also in Port Glasgow.

The structural engineers have advised us that there are no immediate safety concerns and the regular monitoring and management will continue in addition to the normal programme of maintenance and lifecycle investment.

What happens next?

Permanent remediation options for the buildings are being examined and will be considered as part of future lifecycle investment plans.

We continue to implement the management strategies for affected buildings taking into account any new information and research around RAAC. Officers from the Scottish Heads of Property network continue to liaise with Scottish Government on the approach to be adopted to any further inspections and assessment of the public sector estate. We will take action to follow any further advice issued from government or relevant professional bodies.

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.