Photo of Missouri State Capitol, a grand building featuring limestone, columns, and a dome.

Missouri State Capitol Stone Repair & Renovation

State of Missouri
Architectural Design, Civil Engineering, Landscape Architecture, Planning
Historic Preservation
Jefferson City, MO
Project type

Historic capitol exterior rehabilitation

By the time this project started in 2015, the Missouri State Capitol had weathered nearly a century of exposure to the elements. Built in 1917, the historic limestone (also known as Carthage marble), brick, stucco, and concrete masonry surfaces had deteriorated to the point of affecting building performance and safety. The State of Missouri needed to identify the root causes of the deterioration and design repairs.

Completing a detailed evaluation

Our team worked with the State of Missouri to complete a three-month evaluation of the historic capitol—a National Register of Historic Places-listed building. From telescopic boom lifts, swing stage scaffolding, and temporary scaffolding, we used visual and hands-on survey techniques to create detailed inventories of exterior elements such as stone facades, foundations, dome and drum, terraces, steps, railings, retaining walls, and substructures. We also evaluated the waterproofing systems, storm drainage, exterior electrical, and lighting.

Recommending and completing repairs

After completing the exterior evaluation, we provided the State with a report detailing the existing conditions and causes, short-term stabilization recommendations, and long-term solutions and designs to:

  • Repair the concrete foundation structure, waterproofing, and drainage systems
  • Address safety concerns of the portico by removing or stabilizing unsound stones
  • Replace fractured and unsound stones on the terraces, steps, dome, and facades
  • Repair and clean limestone, brick and stucco
  • Replace deteriorated mortar and sealant
  • Repair plazas, terraces, and drainage systems

We provided construction administration services for the $12-million foundation and waterproofing phase that was completed in 2016. The project complied with the Secretary of the Interior’s Standards for Rehabilitation.

Historic picture of intricately carved column capital before it was installed on the Missouri State Capitol.
Column capital before historic installation, c. 1916. Courtesy of Missouri State Archives.
Picture of intricately carved column capitals during condition assessment at the Missouri State Capitol.
Intricately carved column capitals during condition assessment.
Architect uses sounding hammer to assess stone modillion on the Missouri State Capitol.
Modillion stones assessed at the Missouri State Capitol

Project contact

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