Yorkdale Subway Station in Toronto stands as an architectural icon within the city’s transit network. Originally designed by Arthur Erickson Architects in 1974 and completed in 1978, the station is a multi-leveled concrete and steel structure set in the median of the Allen Road expressway. Its most prominent feature is a 600-foot (183 metre) barrel-vaulted glass skylight that spans nearly the entire length of the central platform. Supported by a curved structural steel framing system, this skylight not only provides essential daylight to the station’s platform but also serves as a visually memorable landmark, connecting transit users to the Yorkdale Shopping Centre.
Over the years, however, the skylight has faced persistent water leakage issues that have created safety hazards, particularly by making the platform slippery during rain events. This leakage has not only posed risks to transit users but has also presented ongoing maintenance challenges. Major restoration work in the mid-1990s was implemented to address these issues by introducing a concealed drainage system into the skylight. However, after 30 years of service, water intrusion has become a concern once again, and water leakage has continued to compromise the station’s operational safety and aesthetic integrity.