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 soft cloth 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. Do not use scouring powders or creams; these products contain abrasives that may scratch the surface.
Dust mop interior floors frequently using a clean, non-treated 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. Normally, it will take a person about eight steps on a floor surface to remove sand or dirt from the bottom of their shoes. Normal maintenance involves periodic washing with clean, potable water and neutral (pH 7) cleaners. Soap-less cleaners are preferred because they minimize streaks and film. Mild, phosphate‐free, biodegradable liquid dishwashing soaps or powders or stone soaps are acceptable if rinsing is thorough. Wet the stone surface with clean water. Using the cleaning solution (following manufacturer’s directions), wash in small, overlapping sweeps. Work from the bottom up if it is a vertical surface. Rinse thoroughly with clean, potable water to remove all traces of soap or cleaner solution. Change the water in the rinse pail frequently. Dry with soft cloth and allow to thoroughly air dry.
Bath and Other Wet Areas:
Soap scum can be minimized by using a squeegee after each use. To remove soap scum, use a non‐acidic soap scum remover or a solution of ammonia and water (about 1/2 cup ammonia to a gallon of water). Frequent or over‐use of an ammonia solution may eventually dull the surface of the stone.
Outdoor Pool and Patio Areas:
In outdoor pool, patio, or hot tub areas, flush with clear water and use a mild bleach solution to remove algae or moss.
Exterior Stone Maintenance:
The large expanses of stone generally found on exterior applications may make it impractical to perform normal maintenance on a frequent basis. Large installations, however, should be given periodic overall cleaning as necessary to remove accumulated pollutants. Easily accessible stone surfaces such as steps, walkways, fountains, etc., should be kept free of debris and soiling by periodically sweeping and washing with water. Normal maintenance should include periodic inspection of stone surfaces for structural defects, movement, deterioration, or staining.
When discussing care and cleaning procedures with your maintenance staff, there are recommended do’s and don’ts that should always be followed:
Do dust mop floors frequently.
Do clean surfaces with mild detergent or stone soap.
Do thoroughly rinse and dry the surface with clean, clear water after washing.
Do blot up spills immediately.
Do protect floor surfaces with non‐slip mats or area rugs and countertop surfaces with coasters, trivets, or placemats.
Don’t use vinegar, lemon juice, or other cleaners containing acids on marble, limestone, travertine, or onyx surfaces.
Don’t use cleaners that contain acid such as bathroom cleaners, grout cleaners, or tub & tile cleaners.
Don’t use abrasive cleaners such as dry cleansers or soft cleansers.
Don’t mix bleach and ammonia; this combination creates a toxic and lethal gas.
Don’t ever mix chemicals together unless directions specifically instruct you to do so.
Don’t use vacuum cleaners that are worn. The metal or plastic attachments or the wheels may scratch the stone’s surface.
Oil‐Based Stains (grease, tar, cooking oil, cosmetics) —Will darken the stone and normally must be chemically dissolved so the stain’s source can be rinsed away. Clean gently with a soft liquid cleanser, household detergent, ammonia, mineral spirits, or acetone.
Organic Stains (coffee, tea, fruit, tobacco, paper, food, urine, leaves, bark, bird droppings)—May cause a pinkish‐brown stain and may disappear after the source of the stain has been removed. Outdoors, with the sources removed, normal sun and rain action will generally bleach out the stains. Indoors, clean with 12% hydrogen peroxide and a few drops of ammonia.
Inorganic Metal Stains (iron, rust, copper, bronze) — Iron or rust stains are orange to brown in color and leave the shape of the staining object, such as nails, bolts, screws, cans, flowerpots, or metal furniture. Copper and bronze stains appear as green or muddy brown and result from the action of moisture on nearby or embedded bronze, copper, or brass items. Metal stains must be removed with a poultice. Deep‐seated, rusty stains are extremely difficult to remove and the stone may be permanently stained.
Biological Stains (algae, mildew, lichens, moss, fungi)—Clean with a dilute (1/2 cup in a gallon of water) ammonia, bleach, or hydrogen peroxide. WARNING: DO NOT MIX BLEACH AND AMMONIA! THIS COMBINATION CREATES A TOXIC GAS!
Ink Stains (magic marker, pen, ink)—Clean light colored stones with bleach or hydrogen peroxide. Use lacquer thinner or acetone for dark‐colored stones.
Paint Stains—Small amounts can be removed with lacquer thinner or scraped off carefully with a razor blade. Heavy paint coverage should be removed with a commercial liquid paint stripper. DO NOT USE ACIDS OR FLAME TOOLS TO STRIP PAINT FROM STONE. Water Spots and Rings (surface accumulation of hard water)—Buff with dry 0000 steel wool.
Fire and Smoke Damage—Older stones and smoke‐or fire‐stained fireplaces may require a thorough cleaning to restore their original appearance. Commercially available smoke removal products may save time and effort.
Etch Marks (calcareous stones)—Caused by acids (typically from milk, fruit juices, alcohol, etc.) left on the surface of the stone, some will etch the finish but not leave a stain; others will both etch and stain. Once the stain has been removed, wet the surface with clear water and sprinkle with marble polishing powder. Rub the powder into the stone with a damp cloth or by using a buffing pad with a low‐speed power drill or polisher. Continue buffing until the etch mark disappears and the marble surface shines. Honing may be required for deep etching. This process may require the services of a stone maintenance professional.
Efflorescence—A white powder that may appear on the surface of the stone, it is caused by water carrying mineral salts from below the surface of the stone to the surface and evaporating. When the water evaporates, it leaves the powdery salt residue. If he installation is new, dust mop or vacuum the powder. Repeat as necessary as stone dries out. Do not use water to remove the powder (adding water will only add to the problem). If the problem persists, contact the stone contractor to identify and remove the cause of the moisture.