The development of treatment protocols at the Watts Towers Conservation Project

Frank Preusser, Blanka Kielb, Sylvia Schweri-Dorsch, Christina Fisher, Mariana Ruiz, and Israel Campos


This article provides a review of current and past conservation practices and the development of new treatment proposals for the Watts Towers. The Italian immigrant Sabato (Simon) Rodia built the Watts Towers in the backyard of his house. They consist of 17 interconnected structures, each constructed of a steel core covered with cement stucco and embedded decorative elements. The two largest structures reach a height of 99.5 ft. (30 m). Rodia built the Towers from 1921 to 1954. He did so without assistance and without scaffolding. The Towers are located in the Watts district of Los Angeles County.

A team of conservators, scientists, and research assistants from the Los Angeles County Museum of Art has been working on the review of current and past conservation practices, and the development of new treatment proposals for the Watts Towers since January 2011. After reorganizing and rehousing the extensive treatment archives, the first comprehensive environmental and physical monitoring program in the history of the Towers was established. This program was further expanded when, in 2013, a team from the UCLA Department of Civil and Environmental Engineering joined the effort of Los Angeles County Museum of Art.

This monitoring and measurement program resulted in a significantly improved understanding of the response of the Towers and their individual elements to a variety of environmental stresses, including solar radiation (heat), vibration and deformation due to wind and seismic activities, and corrosion of the metal substrate. It also provided an explanation for the repeated failures of many of the repairs carried out over the past 50 years.

Based on these findings, we are evaluating improved repair and maintenance procedures that promise to be of greater durability, using the recent advances made in building science and the concrete industry. To date, materials that have undergone laboratory and outdoor exposure testing, and that are now applied to the monument on a limited test scale, include elastomeric crack fillers, polymer amended mortars, architectural adhesives, and penetrating water repellents.

Currently we are also evaluating different approaches to corrosion protection, including migrating corrosion inhibitors and embedded sacrificial anodes.

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2014 | San Francisco | Volume 21