United States Capitol Dome Restoration



The Dome of the United States Capitol in Washington, D.C. is the second dome to sit on top of the building and has been the world’s tallest cast iron dome for 150 years. Constructed entirely out of cast and wrought iron, the dome underwent a rehabilitation to preserve it into the next century. The multi-year project included the repair of cracks in the exterior skin, arrest of water infiltration and condensation, the abatement of lead paint and the installation of a new bird-proofing system.

Preserving a National Icon

Thornton Tomasetti has a history with the Capitol dome that includes two earlier renovation projects. For this most recent undertaking, we were retained to analyze the dome structure and surrounding roof areas to determine appropriate loading points for the construction staging required to perform the rehabilitation work.

Accessing the Exterior

The rehabilitation project required hands-on access to 100 percent of the dome’s exterior surface.  Thornton Tomasetti worked with the project team to develop a basis-of-design construction access scheme and performed a detailed engineering review of the scaffolding that was constructed to perform the restoration work.

Read More

Related Projects