RAAC concrete and schools

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.
 

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.
 

Following survey and inspection work undertaken, RAAC has been identified in the following buildings:

• Cornhill School; 
• Hazlehead Academy; 
• Northfield 
• Abbotswell Academy; 
• Quarryhill School; 
• St Machar Academy (Extension);
• Westpark School;
• Hazlehead Swimming Pool (closed);
• Town House Extension.
   

Following publication of the guidance , the Council undertook an initial assessment of all council-owned buildings and developed a survey programme for buildings that could potentially contain RAAC.  That review made use of photographs, building plans, construction dates, and local on-site knowledge to identify several properties that may contain RAAC.  Engineering inspections were than undertaken on these properties. 
 

Assessments were carried out using available property data to identify a shortlist of buildings that could potentially contain RAAC. Assessment by Structural Engineers were then carried out only on the buildings on that list. 
 

There are no current plans to close any buildings. However, the Council will take steps to ensure the safety of building users should the more detailed surveys identify actions. 

To date no work of that nature has been carried out on the buildings with RAAC.
 

All buildings with RAAC are being re-surveyed with further investigation being undertaken.  Given the relatively small number of properties; inspections are on-going and priority will be given to any required work on a risk basis. 

As is normal practice, our regular survey works continue across the remaining ACC estate buildings 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.

We are also monitoring findings of other partners across the public sector as they undertake their own survey work to share learning and experience.  We will continue to monitor the remainder of our estate as more information becomes available.
 

There are no current plans to close any buildings. However, the Council will take steps to ensure the safety of building users should the more detailed surveys identify actions.  There may be some disruption within schools to allow for intrusive investigations etc.  this will be managed on a local basis.

The wellbeing and safety of our school pupils is our upmost priority. 
 

The wellbeing and safety of all school users is our upmost priority. 

If we do have to close schools, we will make arrangements for pupils in the affected schools and would contact parents and guardians as soon as arrangements are finalised. All schools have business continuity plans in place to deal with closure scenarios.
 

A review of HRA assets is ongoing.