Work description and purpose

The TTC operates a corrective maintenance program to seal groundwater leaks inside the subway tunnels and other sub-surface structures, such as subway ventilation shafts.

Beginning February 21, TTC’s Leak Remediation crew will be working on a ventilation shaft near Spadina Station, specifically within the “Norman B. Gash House” Spadina Station entrance at 85 Spadina Road. The ventilation shaft opens on the roof at the back of the “House”.

Work hours

To maintain the highest safety standards for TTC workers and TTC passengers, work can only be carried out when the subway is not operating. This work will take place Monday through Friday between 2 a.m. and 5 a.m. and is scheduled for approximately 14 night shifts to complete.


All necessary equipment and materials required for this work will be delivered on a subway work-car inside the tunnel close to the tunnel access to the ventilation shaft being repaired/sealed.

General work method

  • During the first two shifts, the crew will assemble and secure scaffolding inside the vent shaft. This work will occur from inside the subway tunnel.
  • Small holes will be drilled into the concrete walls of the vent shaft to insert injectors. We expect that this part of the work will be completed within five shifts.
  • Grouting material to prevent water infiltration will then be injected through the drilled holes. This process will be conducted in stages and could take up to seven shifts.
  • Although the majority of the work is underground, the drilling activity within the ventilation shaft may at times carry noise to street level.
  • The scaffolding will be disassembled at completion of the work.

Any Leak Remediation crew arriving with trucks will access the subway tunnel/ventilation shaft from the station entrance at 85 Spadina Road or at Kendal Avenue.

Thank you for your patience as we work to improve transit in Toronto.

For further information:

Diego Sinagoga, Senior Community Liaison, 416-393-2197;