Lime wash, sometimes known as milk of lime (according to Holmes and Wingate in their book, Building With Lime), is "a free flowing suspension of hydrated lime in water in such proportions as to resemble milk in appearance." It's a simple form of paint prepared from lime. It can be used alone or tinted with mineral pigments to create pastel colors. Lime wash is used as a periodic maintenance for lime plasters as it fills small cracks and has the amazing ability to self-heal. As cracks develop, the lime wash creates crystal growth to seal the blemish. Lime wash is most often used over lime plasters to finish the plaster and make it more resistant to cracking and weathering (Fig. 14.17).
To make a lime wash, combine about one gallon (3.75 liters) of stiff lime putty to about four gallons (15 liters) of water. Mix to the consistency of milk. If
it is too thin, add a little more putty. If too thick, add more water until the desired consistency is achieved. If it is too thick, the wash may show many fine cracks when dry, known as "crazing." It is usually best to mix on the thin side and apply several coats to build it up to the desired thickness. A thicker version of lime wash is made by adding fine silica sand (50-70 grit) at a ratio of 50:50 sand to lime putty.
14.18: Applying cement-lime stucco over chicken wire on the Sand Castle on Rum Cay, Bahamas. Photo Credit: Steve Kemble and Carol Escott
Was this article helpful?