Limestone is a popular natural stone material for a lot of areas in and around the home. This sedimentary stone is made primarily of calcite, and may be studded with small fossils from the shell beds where it was formed. Limestone does vary tremendously in density and porosity, which can make it difficult to determine if it’s right for use in wet areas where it may be prone to both staining and etching.
A lot of the concern surrounding limestone in wet areas comes from a published study several years ago that found some stones like Lagos Azul actually began to dissolve when used on the floors of showers. This made many designers back off from using limestone in wet areas.
Not all limestones are created equally, however. Lagos Azul is a very soft stone that is unable to take a high polish, while Crema Luna can. When properly sealed, harder, denser limestones such as Crema Luna can be used in wet areas, although some care should be taken to use a sealer made for porous stone and to apply it on a regular basis. A well-sealed stone should bead the water up off of its surface; when the limestone is no longer beading, it needs to be resealed.
To help impede staining and prevent any kind of etching of the stone, try conducting the lemon and water test on the limestone to see how porous it is even when sealed. Very reactive stones may not do as well in a shower, but may be fine on a bathroom floor. After using a shower lined with limestone, consider using a squeegee to remove excess water from the walls after each use as well.
Limestone may be one of the softer types of natural stone, but not all varieties need to be avoided in wet areas. Choose harder stones able to handle a polish, seal them regularly, and remove excess water on a daily basis and enjoy the look of limestone anywhere in your home.