Track 7 / Presentation 1
Reconstruction of a Dome’s Stone Cladding and Anchorage - Traditional Stone Anchorage in a Non-Planar Surface
Paul Parfitt
Josh Jaskowiak
Versions of the Pennsylvania State University’s iconic Old Main have stood tall over generations of students since construction began in 1857. First built with the help of undergraduate labor from limestone quarried on-site, Old Main is the heart of an academic community nestled within Pennsylvania’s agricultural heartland. The current Neo-Classical 1930 structure blends carved stone masonry within a motif emblematic of the university’s commitment to “promote the liberal and practical education of industrial classes.” Above it all stands Old Main’s eighty-eight-foot tall Bell Tower topped with a limestone-clad dome and lantern.
A major element of the project was the removal of the existing dome limestone cladding to address stone unit distress and improve water management. Prior to construction, Wiss, Janney, Elstner Associates, Inc. (WJE) performed a condition assessment of Old Main to develop a comprehensive and proactive approach to restoring and maintaining the building’s exterior enclosure and components. The project team utilized a combination of aerial drone surveys, close-up inspections via industrial rope access, and exploratory openings to evaluate the dome cladding’s existing construction and anchorage details. The investigation revealed a variety of conditions that necessitated the reconstruction of the cladding’s anchorage system.
WJE worked with Masonry Preservation Services, Inc. (MPS) to develop an anchorage solution that accommodated a variety of existing conditions and the two-plane curvature of the existing cladding units. Empirical and graphical structural analysis techniques were used to analyze the existing dome structure with historic references originally published by Concrete Publications Limited of London. The analysis informed the design of a custom lateral anchorage system for the 200-pound dome stones that provided restraint against outward thrust but accommodated differential circumferential movement due to thermal expansion. Where new stone units were needed, a 3D laser scan was used to fabricate new limestone units matching the existing unit profile. This paper and presentation will discuss the details of these challenges and solutions and how a commitment to traditional craftsmanship in a team environment made the preservation a success.
Josh Jaskowiak is a professional engineer from New Haven, CT with experience in the fields of preservation engineering, facade restoration and rehabilitation, and historic preservation. He has worked on a variety of historic wood-framed structures, brick and stone masonry wall systems, and facade investigations. He enjoys working on team projects where the existing structure has puzzles that can best be solved with hands-on field work.
