Preserving historic cathedral requires creative collaboration

Client

Roman Catholic Diocese of Charlotte

Location

Charlotte, N.C.

Challenge

With its steep metal roof and masonry up to 10 bricks thick, Terracon engineers and architects had to get creative during leak investigations at the Cathedral of St. Patrick in Charlotte, N.C. Once they discovered the various ways water was getting inside the cathedral, specialized recommendations for repair and prevention were required due to the historic nature of the 85-year-old cathedral, which is the seat of the Roman Catholic Church in Charlotte. Terracon was challenged to discover how new and older materials and solutions might be combined to safeguard the church while maintaining the original overall design and detailing.

Solution

Terracon engineers, technicians, and an architect worked together to perform innovative leak investigations, water testing, and masonry assessments. When the steeple’s sharp pitch made it difficult to safely access the roof from the exterior, they rushed to the attic during a rainstorm to assess leaks from inside. 

To prevent leaking while retaining the cathedral’s brick and copper aesthetic, several design recommendations were made, including removing original parapet coping caps and securing new ones, waterproofing the top of the parapet walls, and constructing copper roof-to-wall flashing. And while building materials have evolved over the decades, our team recommended a soft mortar similar to the original as the best choice for the cathedral. Using today’s harder mortar for masonry repair could have caused bricks to crack as the building naturally expanded and contracted. 

Results

After much collaboration with the contractor and the Roman Catholic Diocese of Charlotte, Terracon’s corrective actions were made keeping the cathedral’s historic integrity and aesthetic intact. No more leaks! The bell tower was inspected as well, but the Diocese isn’t ready to begin that project. Terracon consultants recommended how to best stem the water infiltration in the meantime and remedy it in the future.