Stone tile flooring refers to a number of types of tile including Travertine, Marble, Slate, Limestone and Granite. These tiles are made of materials which are naturally found in nature, and mined from quarries and mountains. Each type of stone tile material has different properties which must be taken into consideration when selecting tile for various locations throughout your property. The following gives a brief overview of these properties.
The absorption rating refers to how naturally porous a material is. More porous materials will be more prone to staining and should not be used in high traffic areas. In addition, more porous materials will also be prone to cracking when exposed to extreme temperatures such as freezing.
Stone tiles have 4 levels of absorption:
Non-Vitreous is the highest absorption level, meaning it is rated the most porous. Types of non-vitreous stone tiles include Sandstone. These types of materials should not be used in damp environments such as on a pool deck, in kitchens or in bathrooms.
Semi-Vitreous stone tiles including Travertine and Limestone are less absorbent. While they can tolerate damp environments when sealed correctly, generally the more moisture they are exposed to, the higher the upkeep.
Vitreous stone tiles include Slate. This is the standard rating absorption level for most flooring stone tiles. They are appropriate for most low traffic indoor areas and outdoor applications including decorative walls.
These materials are water resistant. Impervioius stone tiles are generally easy to maintain and can be used in a variety of applications including high traffic areas such as kitchen and bathrooms. Impervious stone tiles include Granite.
Natural stone flooring tiles are assigned a grade corresponding to the overall quality of the material. This can refer to physical attributes such as size, shape, and thickness, as well as the appearance on the surface. Generally there are three grades:
Grade 1 tiles are composed of high quality materials and have an overall uniform composition.
Grade 2 tiles have minor defects. This can include scratches to the surface, chips, or irregular appearance.
Grade 3 materials have visible defects. They are highly irregular in size, shape, surface and contain deep scratches and chips. Grade 3 materials, however, can still be used in applications where there is a desire for a distressed look.
Coefficient of Friction
Coefficient of friction of natural stone tiles refers to how slick the materials are. The higher the number, the more friction, and thus traction there will be. The Americans with Disabilities Act (ADA) requires a minimum dryness coefficient of .6. This is an important factor to take into account when considering the type of natural stone tiles you want to use in wet environments including the kitchen and bathroom.
Indoor vs. Outdoor Rating
Indoor vs. Outdoor rating refers to how well a certain material will do in different applications. Some stone tiles are better suited for outdoor applications than others due to this, and some of the factors mentioned above. Stone tiles with a low Coefficient of Friction will be slippery during rain and snow storms, as well as with early morning dew. Non-vitreous materials will be susceptible to staining and overall degradation due to exposure to the elements.
Since stone tiles are made from naturally occurring materials, they often contain traces of other elements such as iron which may oxidize in outdoor environment, resulting in the appearance of red on the tile’s appearance. The higher the iron level, the more likely it is that the stone tile will oxidize over time.
Benefits of Using Stone Tile Flooring
Stone tiles add an undeniable element of beauty to your home by bringing in subtle elements of nature into your living spaces. Various uses in tiles and wall decor can help create a calming, zen like feel. While the acquisition process of many building materials do have climate change implications, purchasing locally acquired stone helps cut down on the overall environmental impact of mining and transportation.
Drawbacks of Stone Tile Flooring
With the exception of impervious materials such as Granite and Slate, most natural stone tiles are porous and need to be treated with a sealing agent after installation, and periodically thereafter as routine maintenance. Additionally, some types of stone tile flooring including marble can scratch or chip easily.