Track 2: Materials over Time: Points of Change
4 - Detailing in Transition: The Evolution of Architectural Terra Cotta Detailing Then and Now
Wednesday, September 26
8:30 AM - 10:00 AM
Location: HYATT-Grand EFG
When the National Terra Cotta Society (NTS) was created in 1910, one of the primary goals was to encourage the use of terra cotta in building construction. The society produced guide specifications and details in a folio that was first published in 1914. Prior to this time, architects and engineers relied on various articles and a few books that addressed the use of terra cotta as a construction and architectural material. Terra cotta manufacturers of the time also provided reference details to enable designers to understand the detailing, and to promote its use. Very little information was written or published following the Great Depression, which marked a rapid decline in the use and understanding of architectural terra cotta. Beginning in the late 1970s, the demand for terra cotta began to rise again, but much of the knowledge and experience with the material was lost. As a result of this hiatus, no standards were established and this essentially remains true today.
Many valuable lessons were learned from early 20th Century terra cotta buildings. As architectural terra cotta became more widely used and building heights continued to increase, the early terra cotta clad buildings began to age and the first generation of distress emerged. Improper maintenance of these early buildings, in combination with significant variations in the material properties of the terra cotta, resulted in the recognition that guidelines should be established. The body of knowledge represented in the 1914 edition of the NTS folio was generally limited to approximately twenty years of building construction. By the 1927 edition; however, almost thirty-five years of construction, along with maintenance repairs and costs had occurred. The thirteen additional years of experience pushed many of the early buildings through their critical initial maintenance cycles. Failures from improper applications, poor detailing, the inability to manage water infiltration appropriately, and a general misunderstanding of material properties resulted in significant modifications to the folio. A comparison of some of the details and specifications provide insight into the lessons learned. Many of the design and anchorage detailing changes between the 1914 and 1927 editions were based on in-service performance of terra cotta cladding.
Due to accelerated distress and recent failures of contemporary architectural terra cotta, the terra cotta industry is on the verge of another crisis. As such, it is necessary to revisit detailing, installation methodologies and material compositions. This presentation will compare and contrast the early detailing for architectural terra cotta including the 1914 edition of the National Terra Cotta Society publication with 1927 revisions, along with other relevant industry standards and provide an assessment of the lessons learned in the industry from recent failures and how that has translated into revised detailing, material production and installation.
- Upon completion participants will understand how the evolution of detailing of architectural terra cotta is related to design, installation and manufacturing conditions.
- Upon completion participants will have the opportunity to review historic detailing and how that relates to the recent changes and updates in the terra cotta industry.
- Upon completion participants will have a better understanding of the perceived challenges working with a material such as architectural terra cotta.
- Upon completion the participants will understand the ongoing committee work related to architectural terra cotta industry today, in order to ensure that terra cotta remains a viable restoration material.