Limestone is a naturally occurring stone with specific characteristics that make it a great material for some applications. And like any other material that is used for a variety of applications, it is good to know how to work with and care for this practical and versitile material. In this article we will consider not only what surfaces limestone is used for, but also what to keep in mind when working with it. We will also consider some ways to care for and maintain natural limestone.
What is Limestone?
Natural limestone is a sedimentary rock that naturally forms from the sediment that often collects at the bottom of bodies of water (e.g. sallow oceans or beaches). This sediment is comprised of much organic material and contains calcium rich substances (think shells -dissolved or fragmented- and corals). Over time, these substances build up and merge together, forming limestone. So limestone is made up mostly of calcium carbonate much like marble and travertine. However, it is not metamorphosed like marble and it is not chemically precipitated rock like travertine is. In fact, travertine is a specific kind of limestone. Namely, a chemically precipitated one. But that is not the focus of our discussion, so we will not delve into the geologic differences. The main point to take away is that limestone is geologically different from both marble and travertine, but it is composed of the same stuff (calcium carbonate).
Good for Some Surfaces
As with any material, limestone has some advantages and some drawbacks. So some projects will be well-suited for limestone and others will not. Additionally, the environment will play a role in whether limestone is a good choice. For example, limestone is susceptible to etching, so it would likely not be the best material choice for a kitchen countertop. However, in places where there may be a large amount of moisture or even water, it might be an outstanding choice. The key is being familiar with the material and knowing what the project will require.
One of the uses in which a limestone is a good option is for outdoor walking or standing surfaces. Because there is a large amount of water that will inevitably end up on the stone, the material's ability to absorb water becomes a safety benefit. Since limestone is porous, it "drinks" the water that ends up on it. Using a non-porous material like porcelain, quartz, or sintered stone for the same purpose would work, but water would build up on the surface and make it slippery. Therefore, outdoor surfaces that people walk or stand on are a great candidate for limestone. Some of these include:
- Pool Decking
- Hot Tub Surrounds
Inside the home also has areas that could accumulate water on hard surfaces. For example, kitchens and bathrooms are two places where water is used liberally. Having hard surfaces made of limestone in these rooms is beneficial for the same reasons limestone is good for outdoor surfaces. However, there are some uses in these rooms that might not be a great fit for limestone. Kitchen countertops are a good example of a surface that might not be the best use of limestone. Why? Because of the fact that limestone is made of calcium carbonate and will etch if exposed to acidic substances. Kitchen countertops are exsposed to acidic liquids regularly. Here are some surfaces inside the home that are great candidates for limestone:
- Kitchen Flooring
- Kitchen Back Splashes
- Bathroom Floors
- Bathroom Showers
- Bathtub Surrounds
- Bathroom Wall Tiles
Caring for Limestone
Caring for limestone consists of the same basic care practices that other natural stone materials require. These care requirements fall into three basic areas:
- Stain Removal
Performing tasks in these three areas makes up the basics of caring for limestone surfaces. Let's look at each one in greater detail.
Cleaning natural limestone surfaces on a daily basis is a relatively simple process. The only thing to keep in mind is that you will want to use the proper cleaner. The best cleaner to use for natural limestone is a pH neutral cleaner that is formulated for use on natural limestone. One cleaner formulated for natural stone is Lustro Italiano which is one of our brands.
Cleaning limestone with a pH neutral cleaner allows you to retain any sealer that may be on the surface to protect your stone from water and oil based stain-causing liquids.
Maintaining the appearance of natural limestone goes beyond cleaning it with the appropriate cleaner. Keeping liquids that discolor natural sotne out of the pores is an important part of the process too. By treating your natural limestone with an impregnating sealer periodically, you keep oil and water based liquids from getting into the pores as quickly and this gives you an opportunity to clean the surface. There will be times though when you do not get to the spot soon enough; perhaps when a spill or some other discoloration goes unnoticed. This is when stain removers are handy to have at you disposal.
Removing stains is simple but not neccessarily easy. Removing stains that find their way into the pores of a natural stone takes patience and a little bit of time and persistence. Stain removers often come in the form of poultice powders and have instructions for use. The usual method for using a poultice powder involves preparing the stained area by putting a paste made from the powder and water on the surface, covering the area with plastic wrap and then allowing the material to work on the stain. The process is demonstrated on the product page for this stain remover.
A Word About Etching
Many household liquids are acidic and will etch limestone on contact. Even sealers do not protect calcium carbonate from acid since acids breakdown impregnating stone sealers for countertops. These are mainly formulated for repelling water and oil based liquids and work the best on natural stone that is not subject to etching.
However, if you have limestone that gets etched, then you can correct the discoloration by using an etch remover. It will require some elbow grease and some time and patience, but you can correct etching using an etch remover.