by Sarah Marie Jackson, Tye Botting, and Mary Striegel
Historically, applying a sacrificial surface
finish to buildings became more
widespread in European countries after
the seventeenth century as good hardwoods
became scarce, necessitating the
use of poorer quality building materials. 3
In the United States, a much younger
and less populated country, limewash
came into widespread use during the
ninteenth century. Limewash continued
to be used on plaster and more informal
areas even after the advent of oil-based
paints. 4
Traditionally limewash was prepared
on-site by skilled craftsmen and applied
in the spring or fall to take advantage of
optimal temperatures. The basic ingredients
in limewash are lime and water,
although other ingredients were sometimes
included to provide additional
chemical or physical properties. The use
of additives required careful consideration
due to the possible adverse affects.
For example historic recipes often called
for adding tallow during slaking in
order to increase water-shedding capabilities.
The tallow did increase water
shedding, but it also decreased breathability
and the ease of applying successive
layers.
Pigments were often added to limewash
to vary the color of the finish.
Earth-based pigments were used historically
to maintain consistent color and
limit changes from the alkalinity of the
limewash. It was necessary to add pigments
in moderation to limit the weakening
effect of excessive amounts of
additives.
In order to maintain consistency
sufficient limewash to complete the project
was mixed and agitated throughout
application. 5 After the limewash was
prepared, the surface to be treated was
brushed down to remove loose dirt and
then dampened to prevent the wash
from drying too quickly. If the limewash
dried too quickly, carbonation would be
disrupted, resulting in a weak, cohesionless
finish that tended to crack and
powder.
Limewash was applied in thin layers,
constantly maintaining a wet edge to
create a more conformal coat. Multiple
layers were applied, leaving sufficient
time for drying between applications.
Drying times were 24 hours or longer,
depending on exterior conditions such
as humidity and temperature. When first
applied, the limewash appeared transparent,
but as it carbonated and layers
built up, it was transformed into a solid,
matte finish. 6 Three or more applications
were recommended for the initial
limewashing. Annual reapplication was
necessary to counter weathering from
exposure. Successive limewashings required
fewer layers. 7
Table 1. Limewash Recipes Showing Ingredients Used |
Wash |
Name |
Lime |
Part A |
Part B |
Wash A |
Graymont Ivory Hydrated Lime |
1lb. table salt, .5 oz alum, 1⁄3cup unsulfured molasses, 1⁄12 tsp. laundry bluing. Mix in 2 1⁄2 c. hot water. |
Mix 4 1⁄4 c. hydrated lime with 4 1⁄2 c. hot water. Let stand 12 hours |
Mix parts A & B in equal parts. Viscosity 17 seconds at 70 degrees in #4 Ford cup. |
Wash B |
Graymont Niagara Lime Putty |
1lb. table salt, .5 oz alum, 1⁄3cup unsulfured molasses, 1⁄12 tsp. laundry bluing. Mix in 3 c. hot water. |
Mix 8 1⁄2 c. Niagara putty with 4 c. hot water. Let stand 12 hours. |
Mix parts A & B in equal parts. Viscosity 17 seconds at Viscosity 17 seconds at |
Wash C |
Virginia Limeworks Lime Putty |
1lb. table salt, .5 oz alum, 1⁄3cup unsulfured molasses, 1⁄12 tsp. laundry bluing. Mix in 21⁄2 c. hot water. |
Mix 8 1⁄2 c. Virginia Limeworks with 4.75 c. hot water. |
Mix parts A & B in equal parts. Viscosity 17 seconds at 70 degrees in #4 Ford cup. |
Wash D |
Graymont Ivory Hydrated Lime |
1⁄3 cup unsulfered molasses, 1⁄12tsp. laundry bluing, 1⁄4 tsp. clove oil. Mix with 1 1/2 c. hot water. |
Mix 4 1⁄4 c. hydrated lime with 2 1⁄2 c. hot water. Let stand 12 hours. |
Mix together A & B. Viscosity same as A. Add 4 tsp. Schmincke Casein Binding Medium per 1 cup limewash. |
Wash E |
Graymont Niagara Lime Putty |
1⁄3 cup unsulfered molasses, 1⁄12 tsp. laundry bluing, 1⁄4 tsp. clove oil. Mix with 2 1⁄2 c. hot water. |
Mix 8 1⁄2 c. putty with 2 1⁄4 c. hot water. Let stand 12 hours. |
Mix together A & B. Viscosity same as A. Add 4 tsp. Schmincke Casein Binding Medium per 1 cup limewash. |
Wash F |
Virginia Limeworks Lime Putty |
1⁄3 cup unsulfered molasses, 1⁄12 tsp. laundry bluing, 1⁄4 tsp. clove oil. Mix with 1 1⁄2 c. hot water. |
Mix 8 1⁄2 c. Virginia Limeworks putty with 21⁄4 c. hot water. Let stand 12 hours. |
Mix together A & B. Viscosity same as A. Add 4 tsp. Schmincke Casein Binding Medium per 1 cup limewash. |
Wash G |
Graymont Ivory Hydrated Lime |
4 1⁄4 c. hydrated lime mixed with 7 1⁄2 c. hot water. Let stand 12 hours. |
|
Check viscosity 17 seconds at 70 degrees. For each 1 cup of limewash, add 2 tbsps. of Edison. |
Wash H |
Graymont Niagara Lime Putty |
8 1⁄2 c. Niagara lime putty mixed with 5 c. hot water. Let stand 12 hours. |
|
Check viscosity 17 seconds at 70 degrees. For each 1 cup of limewash, add 2 tbsps. of Edison. |
Wash I |
Virginia Limeworks Lime Putty |
8 1⁄2 c. Virginia lime putty with 5 c. hot water. Let stand 12 hours. |
|
Check viscosity 17 seconds at 70 degrees. For each 1 cup of limewash, add 2 tbsps. of Edison. |
Wash K |
Virginia Limeworks Lime Putty |
8 1⁄2 c. Virginia lime putty with 5 c. hot water. Let stand 12 hours |
|
Check viscosity 17 seconds at 70 degrees in #4 Ford cup. |
Wash L |
Graymont Ivory Hydrated Lime |
4 1⁄4 c. hydrated lime mixed with 4 1⁄2 c. hot water. Let stand 12 hours. |
Add sufficient water to achieve mix requirements. (We added 2 1⁄2 c. of water) |
Check viscosity 12 seconds at 70 degrees in #4 Ford cup. |
Wash M |
Graymont Niagara Lime Putty |
8 1⁄2 c. Niagara lime putty mixed with 5 c. hot water. Let stand 12 hours. |
Add sufficient water to achieve mix requirements. (We added 15 c. of water) |
Check viscosity 12 seconds at 70 degrees in #4 Ford cup. |
Wash N |
Mississippi Lime Company |
8 1⁄2 c. Mississippi Lime Co. lime putty with 5 c. of hot water. Let stand 12 hours. |
Add sufficient water to achieve mix requirements. (We added 21 c. of water) |
Check viscosity 12 seconds at 70 degrees in #4 Ford cup. |
|
Applied to handmade brick, modern brick, weathered wood, and rough-sawn new wood with primer. |
|
Applied to handmade and modern brick with primer. |
|
Applied to handmade brick and weathered wood without primer. |
|
It was only after the Civil War that
ready-made paint began to gain popularity
in the U.S. 8 Beginning in the 1900s
limewash was used less often in urban
areas, although its popularity continued
in rural settings until as late as the mid-twentieth
century. Urban areas were the
first to be affected by an increase in the
use of modern, long-lasting building
materials and the rising cost of labor
needed to apply limewash. The time
needed to apply multiple thin layers and
for carbonation may also have contributed
to the waning popularity of
limewash, as ready-made paint was less
time- and labor-intensive.
Limewash is now beginning to see
renewed interest, because its vapor permeability allows for greater water transfer
than most modern finishes. This
property is very important when considering
finishes for historic structures
where dampness is often a problem. The
increased interest may also be attributed
to historical accuracy, aesthetic qualities,
and environmental concern (limewash
produces very small quantities of volatile
organic compounds).
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.