Positive news around Reinforced Autoclave Aerated Concrete within Aberdeenshire Council estate
Investigations by both Aberdeenshire Council building surveyors and structural engineers continue to progress apace across both the schools estate and wider property portfolio through assessments, visual inspections and intrusive surveys.
RAAC is a lightweight prefabricated form of concrete used primarily in roof construction, commonly referred to as RAAC panels, which was used widely between the 1960s and 1980s typically on low rise buildings including schools and housing.
It typically had a lifespan of around 30 years and it was found to be particularly susceptible to structural failure when exposed to moisture when its aerated or ‘bubbly’ construction can allow water to enter the material.
As a safeguard, the Council completed onsite investigations across the school estate where intrusive or high level surveys were required to establish construction and ascertain the presence of RAAC.
This was very much a precautionary measure where previous visual inspections were inconclusive and we are happy to report that there are no further instances of RAAC within the schools portfolio.
We can also confirm that there is no RAAC present in any of our care or respite homes, day centres, training centres, family resource centres or children’s homes. The wider condition survey programme is now turning to sheltered housing units, however an early desktop exercise has been undertaken on complexes with areas of flat roof and a review of recorded information, and on-site investigations, does not indicate the presence of RAAC.
A number of community centres were also captured within school condition survey activities with no issues identified, however an extension to one hall is also to be reviewed on site.
Similarly there are no issues with sports centres or pavilions, swimming pools, libraries or museums.
In respect of council housing, initial desktop analysis and review of previous assessments of non-standard construction house types, does not indicate the presence of RAAC. Housing and Property teams have, however, undertaken a review of registers/systems to identify house types to be reviewed on site based on age and construction type. It has been highlighted that a number of houses which currently have pitched roofs were originally constructed with flat roofs.
While no RAAC was identified in either Gordon House, Inverurie or Viewmount, Stonehaven, it has been located in the roof of the Members Building at Woodhill House, Aberdeen. Initial inspections note installation as being sound, however structural engineers are to undertake an intrusive investigation to establish any defects.
Further intrusive surveys and remediation works have been undertaken to the previous identification of areas of RAAC installations at Mackie and Westhill academies.
Notwithstanding previous inspections, intrusive surveys were undertaken at Mackie Academy in the Learning Plaza and adjoining gyms back in September. As a result it was determined that there was a need for some remedial works to be undertaken to provide further support to cut RAAC panels within the Learning Plaza only. These have now been completed and Learning Plaza is back in operational use by the school.
Initial inspections of the Common Room, Music Room and Radio Station noted installation as being sound with no evidence of cracking or spalling, water ingress or defection between planks. However, further intrusive investigations were again undertaken during the October holidays with minor mitigation measures undertaken and all areas are now back in operation.
At Westhill Academy, initial inspections of the music extension noted installation as being sound, however a follow-up intrusive investigation was subsequently undertaken in September further assessed the issue and again mitigation measures were carried and the area is back in use.
While our remediation and mitigation works at both Mackie and Westhill academies are now complete and classified as ‘low risk’, these installations and roof coverings will still be subject to routine inspections by our Property teams on a regular basis, particularly following any adverse or severe weather event.
Key to maintaining the integrity of the RAAC installations is ensuring that the panels are not affected by water ingress which severely impacts the structural integrity of the RAAC panels.
Aberdeenshire Council Leader Cllr Gillian Owen said: “I would like to thank all our teams from Property and Housing and our external structural engineers for their tremendous efforts in establishing the location and condition of any RAAC within our estate. It continues to be a major undertaking both in terms of desk-top surveys and on-site investigations which is being undertaken quickly and efficiently and I am sure it gives everyone great peace of mind.”
Deputy Leader Cllr Anne Stirling added: “The safety and wellbeing of our residents and customers is our over-riding priority and as a council we will continue to ensure we maintain due diligence to ensure our housing stock, care facilities, school buildings and leisure facilities are kept safe and well maintained.”