Saving Face: Terra Cotta Testing & Treatments with Helen M. Thomas Haney - GSMT Lecture

A brief history and description of manufacturing and installation processes for terra cotta and the challenges of restoring it.
This presentation by Helen M. Thomas-Haney, Principal at Jablonski Building Conservation, will provide a brief history and description of manufacturing and installation processes for terra cotta. However, the focus of the presentation will be the practice and challenges of repairing deteriorated terra cotta from surveying and probes, to testing to characterize the material and help determine the causes of deterioration, and common restoration techniques.
Architectural terra cotta is plain or ornamental building units consisting of fired mixtures of clay, fusible materials, and grog with a glazed or unglazed ceramic finish. Manufactured in the United States starting in the mid-1840s, architectural terra cotta flourished in the late 19th and early 20th centuries as a less expensive alternative to carved stone. The basic fabrication process for architectural terra cotta has remained the same for the past 150 years. Clay is shaped into the required form, dried, then glazed, and fired.
There are five common methods of fabrication including hand-pressed, extruded, slip cast, ram pressed, and hand sculpted. While no one case of deterioration in terra cotta is ever identical to another due to the variations with the material, manufacturing processes, installation, and weathering conditions, there are some common types of failure-glaze crazing, glaze spalls, clay body spalls, missing units, and deteriorated metal anchoring.
Helen M. Thomas-Haney is a Principal at Jablonski Building Conservation, Inc. with 19 years of experience as an architectural conservator. Her expertise in developing carefully designed testing programs provide clients a better understanding of what is possible in restoration and conservation.
Ms. Thomas-Haney's special interests include metals, masonry and masonry testing, modern materials, and implementing conservation treatments. She is a Professional Associate of the American Institute for Conservation, a Recognized Professional with the Association for Preservation Technology, and is a former board member of the Northeast Chapter of Association for the Preservation of Technology.

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Thank you! Informative on the Freeze-Thaw cycle