Stone, clay, terrazzo and concrete floor care
As new health care facilities are built and older ones remodeled, environmental services managers are often faced with maintaining and restoring different types of floor coverings.
For instance, natural stone and clay tile, terrazzo and decorative concrete are being installed in lobbies, hallways, cafeterias, kitchens and other high-use areas of health care facilities and some environmental services managers are having to work with these materials on a large scale for the first time.
The benefits of low-maintenance hard-surface flooring include durability and less frequent refinishing and restoration compared with vinyl composition tile (VCT) and other surfaces that require topical coatings or finishes.
Restoration equipment
The correct cleaning and maintenance equipment is necessary to complete tasks properly and within budget. Stone and similar hard flooring materials generally have no topical sacrificial coating to protect them from abrasive wear because the materials need to breathe. This makes prevention and maintenance especially important because it delays the need for expensive and time-consuming restoration procedures. In general, nearly all abrasive scratching can be prevented by frequent damp mopping, dry soil removal and 12- to 15-feet of entry matting at all entrances and exits.
Among the most recent restoration advances are wet and/or dry diamond- impregnated floor-polishing pads of varying grits (500 to 3,000) that can be used as part of a daily/routine maintenance program under a standard 175-revolutions per minute (rpm) floor machine, 1,500-rpm burnisher or an auto-scrubber. This is a major change from the days when diamond resin, metal disks, special floor machines and a highly skilled technician were required to maintain and restore stone floors.
Several companies now offer diamond-impregnated pads and systems for polishing and light scratch removal on stone floors, including VIC International (www.vicintl.com), Powell, Tenn.; Levetec Surface Preparation and Machinery (www.levetec.com), Redmond, Wash.; and HTC Inc. (www.htc-america.com), Knoxville, Tenn.
Other stone floor maintenance and restoration advances include high-speed scrubbing, stripping and pickup; semi-permanent polymer and urethane coatings; quick-dry finishes; environmentally friendly, “green” floor care products; high-tech testing equipment; odorless no-scrub stripper; plastic-backed brushes; rough surface pads; microfiber flat mops; bucketless mopping systems; and steam vapor for grout cleaning.
Several companies also offer hard-floor wands that incorporate a spinning spray head that connects to a pressure washer, steam cleaner, or portable or truck-mounted carpet extractor. These specialty cleaning wands are good for cleaning grouted or uneven floors (i.e., concrete, ceramic tile and quarry tile) in locations where large amounts of water and pressure will not cause damage or problems. Large and small hand-tools with vacuum pickup are also available for use with these units. Among them is the Turbo tile and grout cleaning wand by Hydro-Force (www.hydroforce.com), Salt Lake City. It’s fast and effective on ceramic tile, stone, concrete and quarry tile.
In addition to the vendors mentioned, local or national suppliers and distributors often sell such specialized equipment and offer training on their use.
Maintaining stone floors
The key to maintaining stone floors is developing a cleaning regimen that takes the characteristics of each floor type into consideration. They include the following:
Natural stone. For daily or routine maintenance of natural stone, environmental services professionals should use neutral pH cleaners. Strong alkaline and acid cleaners and strippers should be avoided because they will damage stone and grout. Do not apply topical urethane or epoxy coatings or polymer floor finishes to stone because they require regular maintenance or stripping and prevent the stone from breathing. To protect the stone and grout from staining, environmental services professionals should apply a penetrating sealer/impregnator when the floor is installed and dry and reapply the penetrating sealer/impregnator every 12 to 24 months, depending on the level of traffic, needed protection and desired appearance.
To obtain and maintain a shine on calcium-containing stone, such as marble, environmental services professionals have several options. One process known as crystallization or vitrification is often used. It is much like spray buffing a VCT floor and involves polishing the floor with a heavy floor machine (140 to 160 pounds), fine steel wool (0 or 00 grade) and polishing with a powder, solution or slurry that may contain aluminum oxide, lacquer and/or an acid. The service frequency will vary from daily to quarterly, depending on the level of traffic and the desired appearance.
Other options include polishing with diamond-impregnated floor pads, resin diamond disks or a powder or compound. Different types and grits of diamond disks are generally required for each type of stone being ground, honed or polished. Polishing stone with diamonds is much like sanding wood; you start with a coarse grit (50 to 400) and progressively work toward the finer grits (800 to 3,000) until the desired shine develops.
Most natural stone flooring can be scrubbed with a white or natural hogs hair pad. Environmental services professionals should not use a coarse, abrasive (black) pad or nylon grit brush because they will scratch the surface. Also do not use a red pad or blue pad because the color of the pad may transfer to the stone flooring. If large, open areas are being maintained, professionals should use an autoscrubber and a white pad in place of damp mopping.
Spots and stains on stone and concrete floors can often be removed or lightened by using a commercially available poultice. Oil-containing solvents or spotters should not be used on stone or concrete as they may cause a permanent stain or discoloration.
Marble. This is considered a soft stone and often has visible veins. Marble scratches easily and will be damaged by acid cleaners. Topical coatings should not be applied to marble or to other natural stone flooring.
Limestone. This is a hard-to-soft stone. It’s common to have a fossil pattern on the surface. It also is acid sensitive. A penetrating sealer/impregnator is recommended to prevent staining. Topical coatings should not be applied to limestone floors.
Granite. A harder stone than marble, granite’s crystalline structure can generally be seen in the surface pattern. Being harder, granite is more difficult to scratch than marble and is resistant to most acids. A penetrating sealer/impregnator is recommended to prevent staining; topical coatings should not be applied to granite surfaces.
Most stone professionals consider diamond disks to be the only viable option for polishing granite. However, several companies now offer a polishing powder for granite that can be used to remove scuffs and light wear patterns. Powder polishing will not remove scratches from granite due to the hardness of the stone.
Slate. Considered a soft stone, slate can be stripped like clay or ceramic tile floors. Stripping should be followed with a mild acid rinse (4 ounces of white vinegar to 1 gallon of water) to remove any grout haze that may appear. Environmental services professionals should not use high-pressure spray units because they can damage the stone. After cleaning, allow the floor to dry for 12 hours and then apply one or two coats of a color-enhancing penetrating sealer. Topical coatings are sometimes applied to protect slate from abrasive wear and to increase the gloss or shine of the floor.
More stone materials. For other stone materials, contact the manufacturer, contractor, company that installed the floor or a company that specializes in stone care and restoration. In all cases, when working with stone floors, test the products and processes in a small, 4-inch-by-4-inch area before widespread use to avoid damage to the floor surface.
Smooth stone surfaces that become dull or scratched often can be restored by diamond grinding, honing and polishing. Marble and limestone typically need more maintenance than granite, because they are softer and tend to wear, scratch and dull more quickly. To avoid problems when maintaining stone flooring, environmental services professionals should get proper training or use the services of a qualified stone restoration company.
Other tile types
Environmental services professionals should not apply a topical coating or finish on ceramic, porcelain and quarry tile because they are unnecessary and will increase the frequency, complexity and cost of periodic and restorative maintenance. An impregnator or penetrating-type seal may be used on unglazed tile and the grout lines to protect against staining and discoloration.
Use a neutral pH cleaner for regular daily or routine maintenance. Avoid harsh acid or alkaline chemicals, as they tend to damage the grout. If a harsher alkaline product must be used for spot removal, deep cleaning or stripping, limit dwell time and neutralize after cleaning with a mild acid solution (one having a pH of 3 to 4) and then rinse twice with clear water.
On grouted floors, the most effective process for removing water, slurry or cleaning solutions is to use a wet vacuum, not a mop. When used with clean water, wet mops (string or micro-fiber) are acceptable for solution application, but are not as effective as wet vacuums for slurry or solution removal.
Terrazzo and concrete
Terrazzo is a masonry floor that is similar to concrete, except that the floor contains 70 percent marble chips in a Portland cement or epoxy matrix. A penetrating sealer and/or topical coating, such as a polymer floor finish or sealer, can be applied to the surface for added protection against wear and staining. Alkaline cleaners/strippers should not be used as they can permanently damage the floor due to crystallization of the alkaline salts contained in the detergent. This can cause the loss of stone chips and pitting.
Basic concrete care guidelines include making sure the concrete is clean, dry and dust-free; scrubbing with a neutral cleaner followed by application of a mild neutralizer and thorough rinsing; then allowing plenty of time for the surface to completely dry before applying a penetrating sealer and/or a topical coating or finish. All manufacturer instructions should be closely followed.
Temperature and humidity are important for achieving good leveling, adhesion and shine. Several coats are normally required, with adequate drying time between each coat. Concrete sealers are often mopped, rolled, brushed or sprayed on to the floor.
Depending on the intended use and the specific product used, floor finish is sometimes applied on top of a sealer for added protection. Special products are recommended for use on exposed aggregate concrete and exterior applications that are exposed to sunlight, moisture and changing weather conditions.
Unique requirements
Stone and clay tiles, terrazzo, concrete and other types of flooring each have their own unique cleaning methods and requirements, but with the right guidance, hospital environmental services professionals can learn to keep these surfaces in great condition.
William R. Griffin is president of Cleaning Consultant Services Inc., Seattle, and a former hospital environmental services manager. He can be reached via e-mail at wgriffin@cleaningconsultants.com. The opinions expressed in this article are his own.
| Sidebar - Training and Certification |
The Institute of Inspection, Cleaning and Restoration Certification (IICRC) offers two formal certification courses related to floor care. The Stone Maintenance Technician and Floor Care Technician are excellent training programs for floor care professionals. For those already proficient in floor care techniques, advanced training to become a certified floor covering inspector may provide additional opportunities for advancement. For information on these and other certification programs, log on to www.iicrc.org or call (360) 693-5675.—W.R.G. |
This article first appeared in the July 2008 issue of HFM.
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