Preserving an Architectural & Artistic Treasure

Pennsylvania State Capitol Building

Harrisburg, Pennsylvania

Peristyle Deck Restoration

Project Profile

Project Background

  • Italian Renaissance-style statehouse described by President Teddy Roosevelt as “the handsomest State Capitol I ever saw”
  • Capitol’s vaulted dome rises 272 feet and weighs 52 million pounds
  • Building contains a large collection of priceless historical artwork
  • Leaks through the building’s peristyle decks had been documented as early as the 1950s
  • MPS was commissioned to determine where water was entering the building and what should be done to stop the water infiltration; MPS then implemented a pilot phase to set the quality standard for the repairs and prove the efficacy of the preservation approach

Project Challenges

  • Asphalt membrane below the decks’ massive granite pavers was keeping water trapped in the system
  • Granite pavers needed to be removed and reinstalled in order to access and remove the brick masonry and asphalt membrane; areas had to remain watertight throughout this process
  • Significant structural modifications were required to stabilize the large granite deck and facade stone panels and the concrete and masonry sub-structure, including the use of custom stainless steel and Cintec grouted anchors
  • Building needed to remain fully operational during restoration process; work area was extremely confined, limiting project progress

Project Approach

  • Extensive scaffolding and netting/protection was installed to safely access work areas and protect lower Ludowici tile roofs
  • Granite pavers were moved out of the work area, and new reinforced concrete beams and curbs were installed
  • A new lead-coated copper roof was installed over the pavers; roof had to mimic the decorative profiles of existing stone walls and column bases
  • The new anchorage system was used to structurally bolster the masonry wall assemblies and prevent overturning
  • The ornamental granite balustrudes just above the pavers were also disassembled and restored as part of the peristyle deck restoration

“MPS delivers value during every stage of a project, be it during project conception or during construction. At the Pennsylvania State Capitol they developed a carefully thought-out waterproofing design solution. During a subsequent pilot program, they successfully implemented the work as conceived by the design team. Their decades of experience, creativity, and problem-solving make them a truly invaluable part of the team.”

Niklas W. Vigener
Senior Principal
Simpson Gumpertz & Heger