Reinforced Autoclaved Aerated Concrete (RAAC) is a lightweight form of concrete used in roof, floor, cladding and wall construction from the mid-1950s to the mid-1980s. It is present in Toronto District School Board schools and hundreds of other schools across Ontario.
At the TDSB, 27 of 579 schools currently have either full or partial RAAC roofs (as of
January 2026).
There are plans to replace RAAC roofs at the remaining 27 schools by 2029. It’s estimated that it will cost nearly $120-150 million to replace the remaining RAAC roofs in TDSB schools.
It is safe to be in the schools with RAAC roofs present. These roof panels have been reviewed and evaluated by professional engineers. Any roof leaks that may occur are closely monitored and, as an added measure, the TDSB sends roofing contractors to some of the schools with RAAC roofs where snow can accumulate to clear the roofs following heavy snowfalls. A report is prepared immediately after the snow removal and provided to a professional engineer for final review and signoff.
If for any reason, TDSB staff felt there was a potential safety issue at any of these schools, students and staff would be moved out of the directly impacted area or the entire school.
As the building must be empty when replacing roofs (not only because of the work overhead, but due to asbestos abatement), this work is primarily conducted during the summer months with some finishing work completed in the fall, along with interior finishes such as lighting and ceiling tiles.
The TDSB receives approx. $247 million per year in School Condition Improvement funding from the Ministry of Education to address renewal of critical infrastructure, including roofs and structural work. An increasing proportion of this funding received by the TDSB is now going to replace RAAC roofs and will continue to do so until all impacted roofs are replaced.
Below, is a list of schools that currently have RAAC roofs present.