St. Paul, Minnesota
Built in the early 1900s, The Cathedral of Saint Paul is constructed in the Classical Renaissance style of architecture. It’s crowning glory is it’s stunning, copper clad dome accentuated by a cross visible to most of the city.

RSI provided engineering and inspection services for the restoration of the Cathedral of Saint Paul. Our Scope of Work included the redesign and replacement of the entire roof, including the copper dome, transept, apses, sacristy and various flat roof sections.
Much of the dome’s exterior skin consisted of interlocking copper panels. As the interlocking sections approached the base of the lantern, the copper changed into a Bermuda-style panel. As the skin was replaced, the architectural copper sections that had been removed for restoration and repairs were reinstalled.
Cathedral Restoration Details
- The copper columns are filled with over 28,000 board feet of polyurethane foam.
- The restoration used over 1,500 pounds of solder.
- There are 42 miles of mortar joint repair.
- Over 2000 rolls of ice and water shield and 30-lb. felt were used.
- Over 1000 rolls of PyroKure 600 and /or red rosin sheet were used.