Terra cotta, an enriched molded clay, has been used as building material primarily during the 19th century up to the 1940s as either load bearing capacity material or as a decorative veneer. The surface of terra cotta units can be finished with a glaze or no glaze, which simulates a variety of natural stone finishes. Typically, terra cotta is hollow cast to reduce its overall weight. In addition, internal webbing enhances load-bearing capacity and provides a point for an anchoring system.
Terra cotta failures are most often attributed to moisture penetration problems, which then causes corroding of the steel anchoring systems. Further problems may include improper installation, faulty flashing, failed joint material, stress related deterioration, and inappropriate repairs.
The restoration process for terra cotta can consist of repairing localized spalling and cracking with the specialized patching materials to replace terra cotta pieces. When pieces are required to be replaced, the terra cotta is removed, shipped out to the manufacture for reproduction, and typically takes several weeks for return of the newly constructed pieces. Installation of new pieces often requires stainless steel anchoring and modern flashing techniques to prevent premature failure and to ensure the restoration will last.