Westmoreland County Courthouse, designed by Pittsburgh architect William Kauffman, was constructed in 1906–1907. The central dome and rotunda drum are supported by a steel truss system. The original dome was clad with terra cotta that was completely replaced in the early 1970s. The new terra cotta soon exhibited signs of severe deterioration, and it was determined that it could not be salvaged.
The goals of the dome reconstruction were to restore the original appearance of the dome, provide a durable and serviceable exterior cladding, and integrate the new system with the existing structure. A number of replacement materials were evaluated including terra cotta, glass-fiber reinforced concrete, precast concrete, cast stone, fiber-reinforced polymers, cast aluminum, and sheet aluminum with stamped aluminum ornament. The characteristics, common uses, advantages, and disadvantages of each potential replacement material were examined. Criteria were developed for selection of the replacement material.
This paper focuses on the criteria used in the selection of a replacement material for terra cotta. The decision to salvage the original terra cotta of the drum and replace the newer existing terra cotta of the dome is examined. The characteristics of the various materials considered are discussed, and the process used in confirmation of the selected material is reviewed.