A former Domtar employee claims it was widely known the company’s Reinforced Autoclaved Aerated Concrete (RAAC) ceiling panels used at the Ontario Science Centre (OSC) were suspect by the 1980s. The verified but anonymous source was employed at Domtar in the 1980s and says by then the Siporex brand was already withdrawn from the market … Continue reading Domtar RAAC roofing panels were known to be problematic 40 years ago: Source