Stone has been used in interior and exterior design for centuries, from the smallest embellishments to entire buildings. Stone tile flooring is a mark of quality and style, and is used in many homes, especially in the bathroom. But not all stone is created equal. While appearance and price are major considerations for most people, there are a few more practical features you should be aware of, too.
Tile Ratings
The very most important thing you need to consider before installing any kind of tile, including stone, is whether or not the tile you choose is suited to the space you intend to use it in. Most importantly, you want to be aware of:
- The Mohs rating of the stone, which determines it’s relative hardness – and how easily it can be scratched. Stone tile, notably marble, is softer and more susceptible to damage than ceramic or porcelain.
- The PEI wear rating can help determine how well a particular type of stone will hold up in a high-traffic area. The higher the number the better.
- The water absorption rating is especially important for tile used in a bathroom or outside. The lower the number, the better. More porous stone tile can absorb and hold water and even begin to mold.
- Most tiles are classified as impervious, vitreous, semi-vitreous, and non-vitreous, ranging from least to most absorbent.
- The grade of the tile (usually ranked 1 [high] to 3 [low]) determines the overall quality of the tile. Lower grades will have some flaws or chips that make them a poor choice for flooring.
- Coefficient of friction is how slippery floors are when dry and wet. This is incredibly important for safety in a bathroom. Higher numbers are better, and anything lower than a .6 dry rating is a poor choice for a bathroom.
- Many stone tiles are also rated for indoor or outdoor use; chemical resistance; potential for oxidation (meaning, parts of the stone that can rust when exposed to water); frost resistance; and the degree of tone variation in color between tiles.
Stone Naming
Stone tile floors come in a rainbow of colors, from pure white to vibrant greens, oranges, and pinks. But the naming system for various types of stone tile can be confusing. All stones have a scientific name (which refers to the geological composition of the stone and where it was quarried). Many common stone types also have commercial names, which group together visually similar stones even if they’re geologically different. That said, these commercial names don’t always give you much information. Serpentine, for example, refers more to a green color than to a type of stone or a single quarry location. Some stones (including onyx and some marbles) may not even be named for the type of stone they actually are, geologically speaking. So always consult with an expert to find out exactly what you’re buying!
Stone Finish
Stone tiles are available in an amazing array of colors, and can be finished in several different ways. Depending on the type of stone you choose, it can be processed in several different ways.
- Stone that is split or cleft is broken off from a larger slab to form a naturally slightly uneven, textured surface. Split stone tile are left with their natural texture.
- Stone can also be polished to create a smooth, glossy, reflective finish to emphasize crystals or veining in the stone.
- Others are honed to create a smooth finish without the buffed gloss of a polished stone. This can offer better slip resistance for use in a bathroom.
- Some stone is intentionally textured, using sandblasting (for a lightly roughed surface); brush-hammered (to create a rough texture); or tumbled for a rough, rustic, more natural appearance.
Many stones must be filled or coated with a polymer to fill gaps and improve water tightness. They are then sealed to prevent staining and maintain the appearance of the stone.
Installation
A shorter-term consideration is that stone tile is somewhat more difficult to install than ceramic or porcelain tile, for the simple reason that it’s a bit more fragile. Stone needs to be installed on a very even, flat surface, and should always be installed by a professional. Poor installation can emphasize the natural faults in a piece of stone tile. It can also significantly reduce the life of a floor that should theoretically last as long as your house. Professional installation is also important because certain thin-sets and grouts can stain certain stone tiles – a costly mistake you definitely DON’T want to make!
And Maintenance
When choosing a type of tile to use as flooring in any room, it’s important to consider not only the way a tile will look, but also how well it will hold up over time (and what you’ll have to do to keep it looking good). This is especially true with stone tile, which is much easier to stain and scuff than ceramic or porcelain tile. Because stone is naturally porous, you’ll need to routinely polish it and reseal it annually to prevent staining. And because many stones (including marble) are reactive to acid, you may not be able to use standard household cleaners. Stone is easier to resurface for hiding damage over time. But because it’s typically softer than ceramic or porcelain tile, it’s also more easily damaged and requires gentler care.
Adding stone tile is a great way to improve the value of your home, to say nothing of the style. But it’s a choice that you shouldn’t make lightly, with many factors that impact the look, feel, and longevity of your new floor!
