The $15.8-million skirt restoration of the U.S. Capitol dome, which is composed of nearly 4,500 tons of iron, resolved deterioration and life-safety concerns involving cast-iron decorative and structural elements located at the dome's exterior. Work included interior and exterior lead-paint abatement and repainting of all cast-iron plates and trusses; repair of severely deteriorated cast iron; repair and cleaning of sandstone and historic brickwork; the application of protective epoxy coatings; and drainage redesign and improvements.

Paint removal revealed numerous unforeseen challenges. After the removal of lead paint from the original sandstone, lead was still detectable three to four inches into the stone. Full remediation was not an option. Instead of using Dutchman repairs, the project team chose to repair the cracked units to limit the lead-abatement procedures required for stone removal.

After removal of the paint on the cast iron, numerous cracks and other unforeseen repair items were found. Many of these repairs required a new design solution. This new work resulted in a 43% increase in repairs.

Despite the added issues, the project team was able to complete its work two weeks ahead of schedule—in time for the 2013 presidential inauguration—and more than $1.3 million under budget.

U.S. Capitol Dome Skirt Restoration, Washington, D.C.

Key Players

Owner Architect of the Capitol

Design Firm Hoffmann Architects

General Contractor Gilbane-Christman Joint Venture

Construction Manager Jacobs Project Management

Structural Engineer Thornton Tomasetti

MEP Engineer Summer Consultants

Environmental Consultant Aerosol Monitoring & Analysis