Washington, DC

Thomas Jefferson Memorial


Originally constructed in the early 1940s, the Thomas Jefferson Memorial sits on the south bank of the Tidal Basin adjacent to the Potomac River in Washington, DC. The memorial is one of the nation’s most recognizable landmarks and draws millions of annual visitors. SGH provided structural engineering services as part of a phased restoration to various elements of the monument.

During the first phase that included a roof restoration and cleaning, SGH helped the project team implement repairs and upgrades to extend the memorial’s useful life. Highlights of our work include:

  • Collaborating with the contractor to prepare a construction plan for removing 140 marble tiles on the northern portico roof to facilitate the installation of new roofing
  • Reviewing the design for a wire cable system to prevent pieces of the marble volutes from falling from cracked column capitals
  • Developing permanent repairs for cracked stone components, including column capitals, marble panels at the architrave, and a limestone soffit panel
  • Designing a metal platform and ladder system to provide safer access to attic space in the northern portico
  • Evaluating the existing structure to support scaffolding during the project

The Jefferson Memorial required precise and delicate repairs to preserve this iconic national landmark and make it safer to access. Each cracked stone required a specific detail based on its location and material to address the deterioration while accounting for thermal movement and individual support conditions to mitigate future damage. With careful planning and thoughtful designs, SGH helped the project team implement the necessary repairs while preserving much of the historic fabric and keeping the memorial open to the public during the restoration.

Project Summary



Completion Date


Construction Value


Preservation | Repair & Rehabilitation
Building Enclosures | Structures
Government | Culture & Entertainment
GWWO Architects
Specialized Capabilities
Repair & Strengthening | Preservation