Historic Old Saint Mary’s Church, once the tallest building in Northern California, was only lightly damaged in the 1906 San Francisco earthquake, but its wood floors and roof were destroyed in the subsequent fire. Almost 100 years later, the church has been strengthened while maintaining all of its exterior and interior historic finishes.
Customized Solution
- The first building erected as a cathedral in California, Old St. Mary’s served as the seat of the Archdiocese of San Francisco from 1854 to 1891. Once the city’s most prominent building, much of its stonework was quarried and cut in China.
- As San Francisco Historic Landmark #2 a primary project goal was to avoid any significant impacts on the historic interior or exterior finishes.
- Constructed of unreinforced masonry in 1854, the church floors and roofs were reconstructed in 1909 following the 1906 quake in which most of the masonry walls survived intact. The church was expanded again in 1929.
- Seismic strengthening involved the addition of basement shear walls, a concrete frame in the bell tower, center-cored reinforcement of the brick nave walls, and steel truss reinforcement within the attic space. The center-cored reinforcement of the existing brick masonry walls was designed to provide the desirable ductile behavior of the brick piers. Virtually all of the new structural elements are concealed with no noticeable changes to the appearance of the building.
Highlights
- Architect: Architectural Resources Group
- Owner: Old Saint Mary’s Cathedral
- Concrete shear walls, concrete moment frames, horizontal steel trusses and center-coring of the existing brick masonry walls
- Much of the brick which makes up the original 1854 church was manufactured in Europe and was brought “around the Horn” as ship’s ballast in sailing ships.
Team
Marco Scanu
Senior Project Manager