Limewash is a very old style of paint made up of pulverized limestone mixed with water. It’s been used to not only freshen the appearance of buildings but to discourage wear and tear by acting as a water and insect repellent for both wood and brick surfaces, as noted by the National Park Service.
This type of paint has been seeing a resurgence in popularity for several reasons. For example, it doesn’t have thinners that make it unfriendly to the environment and limestone holds properties that eliminate bacteria and fungus naturally. Further, per Remodelista, limewash doesn’t smell bad in comparison to other commercial paints.
Limewash works best with permeable façades, which allow it to soak into the underlying material. Thus, it can be used on brick inside homes as well as on exterior surfaces. The resulting finish can cover brick completely or offer partial coverage depending on the look you want. If you get tired of your limewash down the line, it can usually be removed with pressure washing or scrubbed it away with a wire brush.
Limewash paint is available commercially, but you can make your own by combining lime putty and water until the desired thickness is achieved. Thinner mixtures containing more water provide less coverage with a hint of the original brick showing through while thicker mixtures impart a whiter look. Whatever the color preference, limewashing is a project many DIYers with some painting experience can tackle on their own.