Building on a water table: What lies beneath the Ken and Marilyn Thomson Patient Care Centre

Michael Garron Hospital’s (MGH) campus is changing on a daily basis. Since groundbreaking in April 2018, MGH’s redevelopment project has achieved and celebrated many milestones such as the demolition of E-Wing and F-Podium, the drilling of 533 cassions 24 metres below the surface, the excavation of 65 000 cubic meters of soil, and the installation of two tower cranes.  

“Once caisson drilling and excavation was completed, EllisDon began to prepare the caisson wall by grinding off excess concrete” says Gabriele Mabrucco, Superintendent at EllisDon. “This made the surface of the wall flat, which provided a suitable substrate to allow for waterproofing installation. The team then began the installation of the waterproofing membrane around the perimeter of the excavation. The lowest portion of the hospital's four storey parking garage is 8m below the water table, so waterproofing is critical to ensure that there are no leaks in the perimeter walls.”

Once the waterproofing was set in place, the installation of rebar and pouring of concrete was able to commence to form the substructure’s (the portion of the structure below the surface) foundation walls, structural columns and floor slabs. “As of the end of December, EllisDon will have poured the last piece of structural slab for the substructure” says Gabriele.

Over the next several months community members will notice the superstructure (the portion of the structure above the surface) emerging from the ground on the west side of the campus and moving in a counter-clockwise direction. Once EllisDon reaches the fifth floor, two temporary hoists (elevators) will be installed at the south side of the building to help lift and distribute materials within the structure.

To date, approximately 11,000 cubic meters of concrete have been poured, with an additional 15,000 cubic meters remaining. All concrete required for the Patient Care Centre is anticipated to be poured by summer 2020.

Once the structure has been poured and the concrete has cured, EllisDon will begin to wrap the perimeter of the building with three types of exterior cladding: masonry (brick), aluminum paneling, and curtain wall (windows). The masonry selected for the Patient Care Centre will tie the new facility into the fabric of the existing campus, while the aluminum paneling and curtain wall will help give the facility a refreshed, modernized appearance.

To learn more about MGH’s redevelopment project visit https://www.tehn.ca/about-us/redevelopment