Limestone is one of the oldest materials, which is highly valued in the construction industry. This sedimentary carbonate rock is typically formed by the accumulation of mineral crystals, mainly calcite. Other minerals that can be found in limestone are aragonite and dolomite, although the latter is rare.
The mineral crystals calcite and aragonite are forms of calcium carbonate (CaCO3).
Please note that even a chemically relatively pure limestone will contain some varying amount of sediments, as well as organic matter often formed from calcareous skeletal fragments. The most common additional components are silt, clay, sand, and chert or flint.
This article will discuss the good and bad aspects of limestone in general while highlighting the properties and where you can find the building material for residential projects. Read on to find out.
Countries With Building-Grade Limestone
Several countries boast a diverse collection of limestone, but the most popular include the USA, France, Spain, Germany, Portugal, Italy, and India.
In the US, the most sought-after building-grade limestone materials are found in Indiana. Most of the North American types of limestone are subject to polishing. You will find crystals polished to a low, medium, and high gloss. These materials are ideal for indoor applications, particularly for decorative cladding and flooring.
Properties of Limestone Worth Knowing
The texture of limestone varies significantly. The majority of the stones traded as limestone have a fine granular or crystalline texture, similar to that of sugar lumps. In mineralogy and geology, they call it saccharoidal.
You will also come to cross a type of limestone with a compact and nearly porcelain-like texture. Commercial limestone of this nature is usually traded as marble. This post will, however, focus on the saccharoidal, medium coarse-grained limestone materials.
Like texture, color also varies. It can be whitish, yellow, gray, pink, light brown, or red. In some cases, the building material can be dark brown or nearly black. This usually happens when limestone contains bitumen as a result of the decomposition and transformation of organic matter, particularly from the soft parts of marine organisms. Generally, limestone is considered quite attractive, but that’s a subject of personal preference.
Another feature that might be of interest is the highly absorbent nature of limestone. Most types of limestone are very porous.
What Happens When Limestone Comes Into Contact With Chemical Solutions And Acids?
As we mentioned earlier in this post, the main component of limestone is calcium carbonate. Calcite can react with any harsh chemical solution that contains acid, regardless of the amount.
What happens is that limestone naturally allows itself to be used to neutralize acid solutions. Any form of acid can easily damage the building material. As such, kitchen application may not be a good idea considering most foods are naturally acidic.
If you want a more acidic-resistant type of limestone, we suggest going for the one with dolomite. Even if you were to opt for dolomitic limestone, also known as dolostone, you still need to keep in mind that the material is highly absorbent.
Porous materials are prone to quick staining if liquid substances get spilled on them. Compact limestones (marble) and granite perform better in this regard. On average, marble is up to 3 times less absorbent. When it comes to granite materials, they are about two times less porous than limestone.
As a quick reminder, though, this article is about stones commercially sold as limestone, not those traded as marble.
Sealers And Impregnators For Limestone
You would probably wonder why people would still use porous limestone in areas prone to liquid spills and stains. It is because the materials are usually designed with penetrating sealers or impregnators.
Impregnators may help prevent water and oil from seeping through the stone. What’s more, they won’t affect the texture and appearance of the stone. However, their effectiveness may not be something to be highly admired in a long-term sense. A sealer may lose its strength and bonding to the stone before you know it.
While there are quality penetrating sealers offered out there, none is likely to withstand constant exposure to harsh and corrosive chemicals used in routine cleaning. That’s because common household cleaners have been shown to alter the chemical composition of impregnators.
Limestone promoters and producers tend to overpraise penetrating sealers. They will claim to solve a wide range of limestone problems, including discoloration, bleaching, crumbling, spalling, powdering, and efflorescence.
Some even will go to the extent of terming their water and oil-proof. Sadly, that is not the case. There’s a difference between being waterproof and water-resistant. We are not bad-mouthing impregnators in any way. Nevertheless, please don’t buy into anything miraculous they say about impregnating sealers.
Final Thoughts And Recommendations
Limestone materials are quite appealing. However, no two stones are created the same way. Components and their percentage in the stone may differ, depending on the circumstances under which they are formed. That’s why you will find limestone products with varying levels of density and hardness. Some stones can easily disintegrate if you expose them to running water.
It is fair to say limestone is just a name. What matters is the quality of the final product. If you are a homeowner interested in using limestone as a flooring material, we would not recommend installing it in spaces with active young children or dogs. The building materials would serve you better in rooms that you seldom use and are not regularly exposed to damaging elements like water, oil, wine, juice, etc.
If you want to install limestone in an area that sees a significant amount of liquid spills, make sure the material is professionally sealed with a top-notch quality penetrating sealer. Remember that you still need to follow a good maintenance routine, even with a good sealer. Otherwise, the sealers won’t be of much help. In line with that, we recommend using cleaning products specially designed for the stone.
Lastly, the type of limestone you choose should have a good performance record.