Title: Documentation and Testing of Nineteenth-Century Limewash Recipes in the United States
Description: Limewash, a mixture of lime putty and water used as a surface coating, has served as an architectural finish throughout the world for thousands of years, but little has been written about the use of this material in the United States. Historic sources cite the use of limewash in a number of different environments, including farm buildings, military buildings, and residences. However, it is not known whether limewash was commonly used throughout the United States or only in certain regions. This thesis attempts to answer that question through historical research by examining published materials that specifically mention limewash. The history of publishing and the current availability of sources were major factors that defined the parameters of this research. Over 1,000 sources mentioning limewash were documented in order to examine spatial and temporal trends in limewash use. Most of the historic publications describe (then) new recipes for limewash intended to improve its performance. These recipes were documented and analyzed according to the additives listed.

This thesis examines the various recipes and the intended effects of a number of additives. Testing was performed to understand basic properties of limewash and additives and to ascertain the legitimacy of historic recipe claims. The tests utilized ASTM methods for adhesion, chalking resistance, and water-vapor transmission. The technical research, in combination with collection of historic paint recipes, seeks to answer questions about the historic use of limewash. Based on these findings, this thesis suggests appropriate uses for limewashes or historic limewash recipes based on testing rather than popular beliefs. This will allow preservationists and practitioners alike to be more informed when choosing a limewash for historic structures.