Stone floors made of marble, granite or limestone are huge investments. When such floors are damaged by improper cleaning, the restoration costs can break a facility manager’s budget. Therefore, it’s essential for distributors to teach customers how to maintain this unique type of flooring.

Buildings have increased their use of stone floors over the past 25 years, according to Phil Calabritto, president of Advanced Stone Technology, a professional stone care company in Toledo, Ohio. During the 1960s and 1970s, ceramic tiling and other surfaces that could be inserted or removed easily were more popular. But, permanent stone flooring has made a big comeback recently, says Calabritto.

“It presents a timeless image for a facility,” he says. “Stone is to hard surfaces what a fine mahogany is to wood. It presents a feeling of high class and quality.”

Like any kind of long-term maintenance, the details of removing dirt from a stone floor are the keys to avoiding the need for costly restoration or replacement. Marble, granite and limestone are stone surfaces that have a natural, polished shine. Under a microscope, one can observe that the shine of the stone’s surface has much to do with infinitesimal grout joints — actual cracks in the outer layer of the stone.

“Stone is polished primarily from fine grinding that makes a smooth finish,” says Calabritto. “A stone floor finish is designed to give surfaces a shine, but the dirt can become impregnated into the grout joints of that finish. If it is ignored for too long, then it can only be removed with strong strippers which will gradually damage the floor.”

Mistakes Set in Stone
Distributors, then, should emphasize the importance of daily cleaning to their customers. The Marble Institute of America (MIA) gives specific guidelines for effective daily cleaning. According to the institute’s recommendations, stone floors should be dust mopped frequently, using a clean non-treated dry dust mop. The MIA’s guidelines further state that people typically need about eight steps from the inside of an entrance to remove dirt from his or her shoes. For this reason, longer mats are recommended for long entryways.

“Hotels are constantly worried about dust and dirt accumulating on a marble floor,” says Chip Hawkins, president of Renaissance Stone Services, a stone installation specialist in North Hampton, N.H. “Heavy traffic increases the probability of small particles etching the floor surface. Continual damp mopping can usually combat the problem.”

The cleaning process can result in dirtying a stone floor more than before, even if it looks cleaner, says Calabritto. “Stone floors don’t hide dirt the same way carpets do, but in the same way, a cleaner can’t rely just on how clean the surface looks,” he says. “The purpose of a mopping solution, for example, is to suspend dirt in the water. But if the mop water is not changed regularly, a fine layer of dirt is left behind. For that reason, I usually recommend using a wet-dry vacuum that removes that fine layer of dirt from a stone surface.”

Acid Rock Cleaning Not Sweet Music
Distributors can save their customers a lot of time and money by clearly explaining what cleaning chemicals and procedures are best for stone floors, says Calabritto. For example, chemicals with an acidic component, such as cleaners that use citrus, will actually do more harm than good to a stone floor.

“Different parts of the United States have different traditions as far as cleaning goes,” he says. “In certain regions, people have been using vinegar or vinegar-based cleaning chemicals for generations. They have a traditional mindset that it’s the best product to depend on and they use it for cleaning everything in the building. While it may be good for many kinds of cleaning, vinegar is an acid, and it can absolutely ruin a stone floor.”

Acidic cleaning chemicals reverse the efforts that gave the stone floor its natural finish, explains Rob Depenbrok, vice president and general manager of Capitol Cleaning Services, a stone cleaning contractor in Chicago. “If an acidic cleaner or an abrasive cleaner is used, it chemically breaks up the stone’s surface and takes the finish right off,” he says.

Tile cleaning chemicals that are designed to remove mildew between tiles usually fall under the category of abrasive cleaners, and they are not to be used for cleaning stone floors.

“A number of times I’ve seen a cleaning person try to use a mildew remover that’s good for ceramic tile on a marble surface,” says Hawkins. “You have to know what kind of surface a product is made for, because tile is not the same as stone, and most common mildew removers will really damage natural stone surfaces.”

The MIA makes four recommendations about cleaning methods that should be off-limits for stone floors:

  1. Don’t use vinegar, lemon juice or other cleaners containing acids on marble, limestone, travertine or onyx surfaces.
  2. Don’t use cleaners that contain acid such as bathroom cleaners, grout cleaners or tub and tile cleaners.
  3. Don’t use abrasive cleaners such as dry cleansers, soft cleansers, scouring powders or creams.
  4. Don’t mix bleach and ammonia; this combination will damage the floor and create toxic fumes.

Hawkins won’t even install marble or other stone surfaces in certain areas if he knows that they will quickly be damaged by acids or abrasives. “It’s just a personal opinion, but if someone asks me to put marble in a kitchen or food service area, I won’t do it. The acids that are being used will eat away at the finish and make it look bad. It’s bad when they have to replace it after only a few years and it makes the stone industry look bad, so I don’t want my company’s name on it.”

If jan/san distributors know that a customer has stone surfaces in or close to a foodservice area, it’s a good idea to stress the importance of cleaning regularly to that customer. Otherwise, expensive measures will be necessary down the road.

Distributors should also caution their customers about using vacuum cleaners that are old or worn-out on a stone surface. Metal or plastic attachments, as well as the wheels of used vacuum may scratch the finish.

Every Stone Is Unique
Each type of stone has a different look and requires a different cleaning method. Distributors need to know the floor type and the differences in stone cleaners to find out what product is best for their customers. For example, although acidic cleaners are damaging to many kinds of stone, they are not as damaging to granite floors, says Hawkins. “Granite is a very durable type of stone floor,” he says. “It can be priced at the low or high end, so it’s a good alternative to marble.”

Granite is also less likely to scratch than marble, according to Depenbrok, which also means it can be expensive. “It costs more for a good granite surface, but in the long run it usually lasts longer than marble,” he says.

Architects sometimes like to mix different stone surfaces for the floor of a building — something that cleaners should pay attention to and that distributors can point out to their customers.

“I’ve noticed that building designers like to use black granite with white marble,” says Calabritto. “Those are two very different kinds of stone that react very differently to cleaning chemicals. We work with some floors that have brass, granite, marble and limestone all on the same surface. What usually happens after a period of time is that the original intent of the architect gets lost because the stones wear in different ways and cleaners aren’t properly educated about how to clean each surface differently.”

Not All Shine
Hawkins points out that limestone is a surface that does not usually have a natural shine. “It most often has a honed surface to it, so you don’t have to worry as much about keeping up the finish to make it naturally shine.”

However, Calabritto points out that facilities often desire a shiny floor, regardless of the material. When cleaners try to make a honed stone floor shine, they create more problems than solutions.

“In the United States especially, we like polished floors,” he says. “The general population thinks that a non-polished floor is dirty. What happens is cleaning contractors try to polish a stone floor like limestone and make it shine, but it isn’t made to shine. They sometimes end up adding all kinds of finishes and chemicals that are not good for the stone.”

Cleaning professionals have experimented with applying finishes to stone floors, but the usual result is a change in the look of the stone. It also doesn’t hold up to the wear of time as well as the stone’s natural finish does. “The stone’s natural surface is what should shine,” says Hawkins. “When an artificial finish or covering is added on top of the stone’s surface, dirt and grime will get caught in the surface much more than it would in the stone’s natural surface.” As a result, the finish begins to yellow over time, not because of the stone but because of the dirt that is actually trapped in the artificial covering.

Stone floors, while having a look of class and high quality, need to be cleaned in special ways to so that expensive restoration can be avoided. In the end, cleaning procedures are even more important than what kind of stone floor is purchased, says Calabritto. “It’s important to decide what the long-term maintenance solutions need to be and how cleaners can realistically attain those solutions,” he says. “Otherwise, a beautiful floor won’t be beautiful for long.”

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POSTED ON: 4/1/2002