St. Michael's Cathedral Rehabilitation


Quinn Dressel Associates worked with +VG Architects and many other disciplines on the Masterplan for the Rehabilitation of St. Michael's Cathedral Basilica. This complex renovation and restoration effort on one of Toronto's oldest buildings was carried out over multiple phases spanning nearly two decades. Due to the age of this iconic structure, and the desire to implement contemporary design features like an elevator and modern A/V systems, QDA encountered challenges that required a specialized engineering response.




After completion of the architectural treatment for the ceiling and during the re-slating of the roof, the large wood bearings for the roof trusses along part of the north and south walls were found to be rotten. We devised a sequential method of support for the roof trusses and the ceilings while the wood bearing members were removed and replaced. The operation was successfully completed without any damage to the ceilings or trusses.


While electrical wiring was being brought to one of the speakers at the main support

columns of the church, the removal of plastered finishes revealed that the brickwork was disintegrating. At this point the structural work for the shoring and support of the columns in the basement had long been completed and the scaffolding erected for the intricate and delicate work on the ceilings had been removed as the project advanced to the completion of interior floor, wall and ceiling finishes.




Upon further investigation several columns needed to be rebuilt, involving shoring around each column through the ground floor to the basement while each of the columns was removed. The construction schedule necessitated that work on several columns was carried out simultaneously. Through careful sequencing of the work settlement of the structure was avoided.


The building contains more than 100 windows of different shapes, sizes, and configurations, all of which required major repairs or replacement as part of the conservation work. Structural modelling of the main east window above the altar allowed us to design the reinforcement for the wood tracery without compromise to the appearance and aesthetics of the fenestration.


The Exterior Conservation work on the Bishop's Palace at St. Michael's was nominated for a 2021 Built Heritage Award by Heritage Toronto.