Horizon Construction’s Managing Director, Phil Holding, is interviewed about the current issues for schools with RAAC and explains what it is, and how it is identified and resolved from project experience.
There is a lot of talk in the news about RAAC affecting the safety of school buildings, so please can you explain what is RAAC?
Between 1950 and 1980, a new lightweight reinforced autoclaved aerated concrete (RAAC) was used in construction. Due to its quicker installation and simpler production, this type of concrete was extensively used as a less expensive alternative to other forms of concrete structures. The key issue with using RAAC was its life expectancy of around 30 years. Thereafter, buildings that had been constructed with RAAC are now at risk of experiencing structural failures. Furthermore, severe problems with RAAC occur when moisture has got into its structure and becomes weak. The good news is that potential problems with RAAC can quickly be identified by construction experts such as surveyors and structural engineers.
What work are you currently completing to resolve issues with RAAC?
Currently, we are working with a school in Essex. The project comprises structural strengthening and supporting of existing RAAC roof structures over various classrooms, gymnasiums, halls and administrative areas. Horizon Construction was engaged by the school and its project managers with DfE funding to undertake critical works over the school’s summer holiday. The completion of remedial work enabled the school to reopen for the new academic year.
What was the extent of RAAC at the school and how were the issues with RAAC resolved?
The works comprised the removal (and subsequent re-use where possible) of ceilings, lighting and other ceiling-mounted equipment, and the fixing of steel angles to increase the end bearing support of the RAAC planks. The detailed surveys completed in readiness for the works included the identification of RAAC planks that had shown signs of stress. Our works included the fitting of timber joists to provide added support and to allow the continued fixing of ceiling mounted equipment such as AC units. On completion of works, the project was independently inspected and certificated for ceilings to be re-covered.
Contact us for more information about RAAC and our construction services in the education sector.