Scope of the Study

by Sarah Marie Jackson, Tye Botting, and Mary Striegel

Cane River Creole National Historical Park (CARI) represents more than 200 years of plantation life. It is home to more than 42 historic vernacular structures. The park consists of Oakland Plantation and the outbuildings of Magnolia Plantation (Figs. 1 and 2). The buildings are constructed of wood, low-fired brick, and, in some cases, bousillage — clay or mud mixed with moss and hair, which is packed around sticks that have been placed between wood timbers.

Park superintendent Laura Soulliere Gates explains the early use of limewash at CARI thus: "Historically nearly all of the buildings at this park were coated with limewash, and that material served multiple purposes in much the same way as the finish coating on adobe in the Southwest. Limewash provided a layer of protection from the onslaught of wind and water that weathered buildings' exteriors. Limewash gave a layer of hardness to both interior and exterior walls that protected softer materials underneath, such as bousillage or handmade brick." ¹

In 2003 CARI considered applying limewash to many of the historic structures at the park. NCPTT partnered with CARI to determine the durability of traditional and modified limewash recipes within certain criteria. CARI wanted to identify a lasting, low-cost limewash that could be applied in approximately three layers and would last three to five years. Quality Finish, a local paint contractor, joined the project to ensure that local craftsmen would gain the experience and knowledge to apply limewash outside of a laboratory setting.

In collaboration with these partners, NCPTT designed a program for testing limewash on weathered wood, roughsawn wood, historic handmade brick, and modern brick. The historic bricks were handmade, low-fired bricks; the modern bricks were newer, factoryproduced bricks that had been salvaged locally from twentieth-century buildings. CARI supplied the materials for the substrate to which the limewash would be applied from supplies they had at the park. Epoxy was later added to the study to take into account its use in preserving the wooden structures at the park. Quality Finish assisted with historical research and prepared many of the samples. The firm researched possible limewash recipes used locally by interviewing community members. Unfortunately, they were unable to identify recipes used in the community and therefore turned to historic and modern published limewash recipes, including a limewash included in the National Park Service’s contracting schedules. ²

Given the scope of the study, NCPTT researchers identified several questions to be addressed through testing:

• Does the source of the lime affect the durability of the limewash?
• Does the type of lime (e.g., hydrated lime or lime putty) affect the durability of the limewash?
• Does the surface material, or substrate, affect the adhesion or the resistance to abrasion of limewashes?
• How do various additives and modifications affect the performance of limewashes?
• Can acrylic-emulsion additives improve or hinder the performance of limewashes?
• How do limewashes behave after long-term exposure to ultraviolet light and temperature?

Originally published in APT BULLETIN: JOURNAL OF PRESERVATION TECHNOLOGY / 38:2-3, 2007

Notes

1. Laura Soulliere Gates, email to author, Aug. 17, 2006.

2. National Park Service Technical Information Center, 'Class C' Cost Estimating Guide: Historic Preservation and Stabilization (Denver: Denver Service Center, 1993), 18.

3. Colin Mitchell Rose, Traditional Paints, available from http://www.buildingconservation.com/articles/paint/paint.htm.

4. Abbott Lowell Cummings and Richard M. Candee, "Colonial and Federal America: Accounts of Early Painting Practices" in Paint in America: The Colors of Historic Buildings 14 (New York: Wiley, 1994), 14.

5. Scottish Lime Centre, Technical Advice Note 15: External Lime Coatings on Traditional Buildings (Edinburgh: Historic Scotland, 2001).

6. Ibid.

7. John Ashurst and Nicola Ashurst, Mortars, Plasters, and Renders, vol. 3 of English Heritage Technical Handbook (Great Britain: Gower, 1995), 47.

8. Roger W. Moss, "Nineteenth-Century Paints: A Documentary Approach" in Paint in America: The Colors of Historic Buildings (New York: Wiley, 1994), 55.

9. ASTM Subcommittee D01.24, Standard Test Methods for Viscosity by Ford Viscosity Cup, ASTM D 1200-94 (West Conshohocken, Pa.: ASTM, 1996).

10. Marcy Frantom, email to author, Sept. 12, 2005.

11. ASTM Subcommittee D01.23, Standard Test Methods for Abrasion Resistance of Organic Coatings by Falling Abrasive, ASTM D 968-93 (West Conshohocken, Pa.: ASTM, 1996).

12. ASTM Subcommittee D01.23, Standard Test Methods for Measuring Adhesion by Tape Test, ASTM D 3359-95 (West Conshohocken, Pa.: ASTM, 1996).

13. ASTM Subcommittee D01.27, Standard Practice for Conducting Tests on Paint and Related Coatings and Materials Using a Fluorescent UV-Condensation Light- and Water- Exposure Apparatus, ASTM D 4587-91 (West Conshohocken, Pa.: ASTM, 1996).

14. Pete Sotos, conversation with author, Nov. 15, 2006.

15. Ruth Johnston-Feller, Color Science in the Examination of Museum Objects: Nondestructive Procedures (Los Angeles: Getty Conservation Institute, 2001), 35.

16. L. Franke and I. Schumann, "Causes and Mechanisms of Decay of Historic Brick Buildings in Northern Germany," in Conservation of Historic Brick Structures, ed. N. S. Baer, S. Fitz, and R. A. Livingston (Shaftsbury: Donhead, 1998), 26-34.

SARAH MARIE JACKSON joined NCPTT in 2005 as a graduate intern to continue the testing for the limewash study. In 2006 she accepted a permanent position with the Architecture and Engineering Program at NCPTT. She received a master’s degree in historic preservation from the Savannah College of Art and Design.

TYE BOTTING is a research staff member at the Institute for Defense Analyses. He served as the NCPTT/NSU joint faculty researcher for three years. He holds a PhD in nuclear chemistry from Texas A&M University, where he did post-doctoral work in nuclear engineering.

MARY STRIEGEL is responsible for NCPTT’s Materials Research Program, focusing on evaluation of preservation treatments for preventing damage to cultural resources. She also directs investigation of preservation treatments geared towards cemeteries and develops seminars and workshops nationwide. She holds a PhD in inorganic chemistry from Washington University in St. Louis.