Maintaining Marble Flooring
January 7, 2008
Of the stone flooring materials on the market today, marble is one of the most popular. It has been used throughout history in some of the world’s most ancient structures. Today we see it in government buildings, banks and transportation terminals, in the lobbies of Class “A” buildings and fine hotels, not to mention many homes.
Marble is a metamorphic limestone consisting primarily of calcium carbonates in the form of calcite, dolomite or a combination of both. Calcite is a common mineral composed of calcium carbonate and is found in abundance throughout the world. It has a hardness factor of 3 and occupies its own position on the Mohs hardness scale. Dolomite is very similar to calcite but contains calcium magnesium carbonate, which makes it slightly harder than calcite, registering between 3.5 and 4.
In its purest form, marble is white with a visible crystalline structure that has a distinctive luster. Different colors and patterns are created when other minerals and impurities are introduced. It is those impurities that give us the wide range of color, hardness and variation in veining associated with marble flooring.
Today’s commercial marble is defined as any stone other than granite that will take a polish, so what you assume is marble may in fact be something else. Marble flooring may be damaged by certain acids or strong alkaline chemicals. They are also more susceptible to staining by grease, oil and rust because of the porosity of the stone. The surface texture of marble may be thermal, honed or polished, giving it a wide range of maintenance methodologies for cleaning.
Initial maintenance for marble flooring will vary depending on the level of gloss the technician is trying to achieve. Marble flooring is traditionally honed to a matte finish or polished to a high gloss; occasionally a technician might encounter a thermal or flame-cut surface, but these are not as common.
Marble tiles are usually honed or polished at the quarry and then shipped ready for installation. When installation is done correctly, dust mopping and wet mopping is all that is required to remove installation soiling. Sometimes the flooring is honed and polished onsite by a professional stone craftsman using various abrasive diamond disks. This may be followed by powder polishing with oxalic acid compounds or crystallized with solutions containing fluorosilicates.
Penetrating seal or impregnators may be applied to the floor surface after installation to reduce the penetration of water, oil and other liquid spills into the flooring. Many times the customer may have the contractor apply aqueous, or water-based, coatings on the floor, even though this is not a recommended maintenance method for stone-type floors. Daily/Routine Maintenance
Sweeping, dust mopping or cloth systems and vacuuming are the most common daily/routine maintenance methods used to combat dust, dirt and grit accumulation. The frequency will depend on the amount of soil and traffic conditions in the facility.
Marble should be mopped on a routine basis with a neutral cleaner or an approved stone maintenance product mixed in accordance with the manufacturer’s recommended dilution ratios. Damp mopping marble will remove superficial soiling, whereas wet mopping will be required to remove moderate soiling. In environments where soiling conditions are heavy, aggressive mopping may be incorporated followed with fresh water rinsing. Liquid spills that occur during the day should be spot mopped up as they occur. Periodic Maintenance
When mopping procedures do not produce the desired results, machine scrubbing will be the next option. Light scrubbing may remove most common soils; however, medium scrubbing may be required for moderate soiling. Generally, the least abrasive synthetic scrubbing pads are safe to use on stone floors; do not use high-productivity pads or stripping pads. Choose the least abrasive pad that will achieve the objective that is desired.
Polishing of the floor may be required to restore gloss levels. The method of polishing will vary depending on the maintenance system selected for the floor. Diamond abrasives, crystallization and powder polishing are the generally accepted methods for maintaining marble. These are three very distinct systems that require training to ensure optimum results.
When the stone flooring has been sealed or finished with aqueous chemical coatings machine-scrubbing and recoating will be required periodically. Light, medium or heavy scrubbing service procedures will be dictated by the soil conditions. Always rinse the floor well after any periodic cleaning to remove any detergent or alkali residue. The number of coating applications will be determined by the amount of seal and/or finish removed in the scrubbing process. Restorative Maintenance
Restorative maintenance for marble floors will usually incorporate the use of diamond abrasives. Diamond disks have abrasives that span grit sizes of 60 (very coarse) to 3,500 (very fine). The aggressiveness of abrasive diamonds required will be determined by the condition of the marble to be honed or polished. The level of gloss desired dictates the level of the diamond abrasives required.
The restorative operation may require several levels of abrasives to achieve the desired results. In addition to diamond abrasives, powder polishing or crystallization may be performed after the diamond polishing to achieve elevated gloss levels. Restorative maintenance procedures using diamond abrasives may last as long as 5 to 7 years with proper maintenance.
When marble flooring is maintained using floor seal and/or finish, it will have to be removed using the stripping and refinishing service procedure from time to time. The removal of the seal/finish from the marble flooring will unavoidably scratch the surface of the stone. These small scratches will be covered when new coats of seal/finish are applied. If cleaning methodology is switched to penetrating seals, crystallization procedures, powder polishes or creams, it will be necessary to utilize diamond abrasives first to remove the scratches. The frequency of stripping and refinishing will depend on the seal/finishes and environmental conditions the floor is subjected to. Most strip-and-refinish procedures on marble floors can last one to two years, and in some situations, even longer.
Establishing a good maintenance program for marble flooring is a combination of program selection and the frequency of individual services performed. If the floor maintenance program is followed correctly, the beauty of the marble will be enhanced and endure for many years.