Award-winning NCPTT Research takes another look at historic building protectant

A door jamb at Cane River Creole National Historical Park is coated with limewash, a traditional structural protectant.

A door jamb at Cane River Creole National Historical Park is coated with limewash, a traditional structural protectant.

Its most popular cultural reference may come out of The Adventures of Tom Sawyer, but limewash (also known as whitewash) is enjoying renewed interest as a protectant for historic structures, thanks in part to research undertaken by NCPTT and its partners.

Limewash has been used as a surface finish for centuries worldwide. It was widely used in the United States from the 19th to mid-20th centuries to protect structures (and fences, of course) against pests and weathering.

Seeking traditionally appropriate ways to protect their plantation buildings, staff at Cane River Creole National Historical Park (CARI) kept coming back to limewash as their solution of choice.

“Historically most 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,” Laura Gates, CARI superintendent, said. “It provided a layer of protection from the onslaught of wind and water that weathered buildings’ exteriors.”

Limewash can be made with just slaked lime and water. But over the years, tradesmen created their own recipes using a variety of additives. The use of limewash faded to nonexistence with the advent of modern paints, improved contruction materials and streamlined labor practices over the latter half of the 20th century.

Unable to find modern research on which of the many traditional recipes would best protect the buildings, CARI turned to NCPTT. The two organizations partnered with Quality Finish Painters to conduct the study. Researchers used finish remnants to confirm the use of limewash on the wood and brick surfaces at the park and followed up with research to determine appropriate recipes.

Boy Scouts clean up alleys on Clean Up Day in the Near South Side community area of Chicago circa 1915. Two scouts are whitewashing a wooden bin while others look on. (DN-0064648, Chicago Daily News negatives collection, Chicago Historical Society.)

Boy Scouts clean up alleys on Clean Up Day in the Near South Side community area of Chicago circa 1915. Two scouts are whitewashing a wooden bin while others look on. (DN-0064648, Chicago Daily News negatives collection, Chicago Historical Society.)

While Quality Finish researched possible local recipes for limewash, NCPTT developed a series of tests for the study.  Using published testing standards, researchers determined that abrasion, adhesion, and artificial weathering would provide the most applicable data for determining the most durable limewash.  Four separate limes and several recipes were chosen to apply to samples of handmade brick, modern brick, weathered wood, hand-sawn wood, and epoxy.

“We found that our limewash recipes performed better on the brick than the wood and similarly on the wood and epoxy,” Sarah Jackson, NCPTT architectural conservator, said.

“On handmade brick samples where a primer was not applied prior to limewashing the limewash performed better after weathering versus samples with a primer.  None of the limewash recipes we tested were durable on wood samples. However, samples with a primer performed better, possibly as a result of wood’s cell structure.”

Jackson has demonstrated limewash application in several venues, including the Traditional Building conference and the International Preservation Trades Workshop.

Share →

4 Responses to The Other White “Paint”

  1. Lou Ann Speulda-Drews says:

    Sarah,

    Have you ever added color to the limewash? I am working on several vernacular buildings dating to the 1880 and 1890s that appear to have whitewash paint on the wood trim, but with a pigment (green) and I’d like to try and match it. Any suggestions?

    Thanks,
    Lou Ann
    Historian/Historical Archaeologist,
    US Fish and Wildlife Service

  2. Lou Ann,

    We did not do any testing on colorwash and I have only a little experience with color additives. I know from our research that it is recommended that pigments are natural to remain stable over time. There are several books on lime that have information on color additives that I can recommend. From my experience we attempted a colorwash one time and had problems matching the color. I would be happy to offer you some assistance if you would like. You can reach me by email at sarah_m_jackson@nps.gov.

    Sarah

  3. allen bridgforth says:

    Recently I heard your presentation on windows in natchez but my question is on lime wash paint. I have a house in central MS that is a raised cottage but the masonary ground floor is actually a half basement with windows at ground level. The construction of the walls, exterior and interior is solid (but soft) brick with plaster on the inside and out. There is no exposed brick. In places there are significant moisture problems resulting in pealing paint as well as plaster. There are many layers of modern paint (all white). Would lime wash be a possiblilty inside and or out? May I use a product like drylock on some of the worst places. thanks for your help

    Allen Bridgforth

  4. David Micetic says:

    I live in Phoenix, Arizona and whitewashed my house three years ago. Not only do I have the whitest house on the block, but I also am now enjoying lower air conditioning bills.I opted not to tint in order to maximize lime’s reflective properties.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>