The Basilica of St. Patrick's Old Cathedral

Collaborating with the owner and Acheson Doyle Partners Architects, SGH designed structural modifications or strengthening associated with installing a new elevator and maintenance catwalk in the attic, modifying floor framing for revised layouts, supporting new mechanical equipment, adding new openings in stone masonry walls, framing a new bell tower, supporting new and relocated liturgical items, and renovating the basement crypt. As part of the crypt renovations, SGH designed a new concrete slab-on-grade with floor niches to accept remains. To address leakage and condensation issues within the crypt, we developed a drainage method to collect water penetrating through the walls and direct it to a drainage system located below the slab.

Built in the mid-1800s, the 9 ft tall brick masonry cemetery wall with brownstone accents is a prominent neighborhood feature and served as the backdrop for many films. Despite previous bracing attempts, the wall developed a significant lean, leading to concerns about the long-term stability. SGH investigated the support conditions and developed a plan to strengthen the wall, while maintaining the characteristic lean. We designed reinforced concrete buttresses inside the wall with pigmented concrete to blend with the brick coloring and carbon fiber-reinforced polymer strips to reinforce horizontal mortar joints. The project also included repointing the wall and replacing damaged or distressed bricks with bricks salvaged from nearby St. Brigid’s Church.