Natural stone has been used as a flooring material for centuries. Its timeless aesthetic, durability, low maintenance and recyclability make it a sustainable flooring choice.

Flooring materials show age differently and at different rates. Some flooring options require frequent refinishing and lose surface quality relatively quickly. In contrast, natural stone flooring, according to the University of Tennessee Center for Clean Products, ages gracefully and can last for centuries, as many historic examples illustrate.

While some estimates indicate a 50-year lifetime for flooring, the National Association of Home Builders expects natural stone, particularly granite, marble, and slate, to last approximately 100 years with proper maintenance.

In a white paper titled “Durability of Stone Flooring in High Traffic Areas,” the Center for Clean Products says, “natural stone, unlike vinyl flooring, coated concrete, or ceramic tile, has continuous color and structure throughout. This integral finish reduces visibility of surface scratches or damage. Materials with integral finishes are easily repairable and thus enjoy a significantly longer life than surface finished materials. Coupled with its durability, this characteristic translates to a low maintenance and repair profile for the product.”

Nevertheless, natural stone laid in high traffic areas will eventually dull due to foot traffic and dirt. However, stone floors need only be swept or vacuumed on a regular basis to remove the abrasive factors that cause dulling.

The Center for Clean Products advises use of entry mats to prevent abrasive particles from entering the building. Stone floors can also be cleaned more thoroughly with chemical solutions as necessary. Such a simple maintenance routine will substantially delay the need for polishing in situations requiring high-gloss finishes.

Life-Cycle Costs

Relatively high material and installation costs for stone flooring may deter some designers from further considering the material. However, because of its enduring useful life and little need for extensive maintenance, natural stone is economically advantageous.

A life-cycle cost (LCC) study commissioned by the Tile Council of North America calculated that although high-quality stone, namely marble and Turkish travertine, has installation costs of $21/ft2 and $12.50/ft2, respectively (as opposed to under $10/ft2 for most other products), their annual expenses are less than those for some competing materials.

Indoor Air Quality

Some flooring products may contribute to poor indoor air quality, particularly due to the generation of dust, allergens, and volatile organic compounds (VOC’s). Dust and allergens can cause respiratory, dermal, and ocular distress, while health affects observed from inhalation of VOC’s span from headaches to respiratory irritation, and some are suspected or known carcinogens.

Volatile organic compounds that source from flooring are associated less frequently with the flooring material itself than with the products used in manufacture, installation, and maintenance or refurbishment. Such products include adhesives, like those applied to carpet padding and tile, as well as chemical finishes, such as polyurethane for hardwood.

Binders commonly used in the production of carpet also emit VOC’s, and even with regular cleaning, carpet harbors particulates that may be allergens or may carry bacteria.

The use of natural stone can avoid both particulate aggregation and VOC generation. Dust and allergens are unable to build up on the surface of stone, particularly when a routine cleaning schedule is followed; the relatively small surface area on a sealed stone floor prohibits this process.

Cleaning can be accomplished with a gentle (non-acidic) soap and water solution. Further, natural stone surface treatments require only abrasion (as opposed to chemical polishing compounds) to achieve a glossy finish, and stone itself contains no VOC’s.

Even the mortar and grout needed to anchor stone do not diminish indoor air quality. Stone sealant, which is conventionally VOCrich, is almost always necessary for protection against stains and scratches, but low-VOC options are now available.

Cleaning Procedures

To clean stone flooring, the Marble Institute of America recommends dust mopping interior floors frequently, using a clean nontreated dry dust mop. Sand, dirt and grit do the most damage to natural stone surfaces due to their abrasiveness. Mats or area rugs inside and outside an entrance will help to minimize the sand, dirt and grit that will scratch the stone floor. Be sure that the underside of the mat or rug is a non-slip surface.

Clean stone surfaces with a few drops of neutral cleaner, stone soap (available at hardware stores or from your stone dealer) or a mild liquid dishwashing detergent and warm water. Use a clean rag mop on floors and a soft cloth for other surfaces for best results. Too much cleaner or soap may leave a film and cause streaks.

Do not use products that contain lemon, vinegar or other acids on marble or limestone. Rinse the surface thoroughly after washing with the soap solution and dry with a soft cloth. Change the rinse water frequently. Do not use scouring powders or creams; these products contain abrasives that may scratch the surface.

Stone Identification

Natural stone can be classified into two general categories according to its composition: siliceous stone or calcareous stone. Knowing the difference is critical when selecting cleaning products.

Siliceous stone is composed mainly of silica or quartz-like particles. It tends to be very durable and relatively easy to clean with mild acidic cleaning solutions. Types of siliceous stone include granite, slate, sandstone, quartzite, brownstone and bluestone.