Maintaining Super Hard Floors
What are Super Hard Floors?
Bob Murrell
Special Contributor
Natural stone, terrazzo, ceramic tiles, and decorative concrete I consider to be Super Hard Floors.
Natural stones such as marbles, granites, slates, and limestones are very common in both commercial and residential environments. Ceramic tiles dominate the commercial restroom and kitchen market. New porcelain ceramic tile technology can give the look of natural stone with even more durability. The terrazzo market is growing once again. Natural polishing of terrazzo is one of the latest and hottest trends. Decorative and polished concrete are also very popular. All of these Super Hard Floor surfaces require proper products and technical support to have a successful maintenance program implemented.
Designing a Stone Care Program
Natural stone conveys the upscale image that corporate management teams want. Stone represents that feel of solidity, perpetual beauty, class and warmth. For these reasons, these and other similar hard surfaces are being installed at exponential rates. There are literally billions of square feet of marble, granite, slate, terrazzo, ceramic tile, and decorative concrete. This means that there is ample opportunity for contractors to specialize in these surfaces as well as conventional maintenance programs. Super Hard Floor programs generally lend to higher profit margins as well, which is a welcome sight in today’s competitive market place.
All natural stone, when used as a building material, requires knowledge of proper long-term protection, maintenance, and restoration to receive the full benefit from the investment. Lack of knowledge can become an expensive practice. It is imperative in today’s market that retail store operators, building owners, and contract cleaners know what type of natural stone surfaces they are responsible for and the appropriate maintenance methods to ensure their lasting beauty and durability. The responsibility to teach and inform these people is that of the suppliers, installers, fabricators, and restoration professionals throughout the stone-related industry.
If you are a BSC or contractor, the first step is to contact a reputable distributor of quality products and technical support who can actually help with the design of a stone care program. Suppliers should offer a quality comprehensive natural stone care product line. Partner with a distributor you can count on for a long-term relationship who has superior technical support.
When designing a maintenance program or before attempting a restoration project, it is necessary to determine the type of stone in question. Is it marble, limestone, granite, slate, terrazzo, or some other stone surface? Stones that contain calcium are polished differently than stones that do not contain calcium. We can therefore group stones into two classifications, those that contain calcium, and those that do not. Stones such as marble, limestone, terrazzo, and concrete all contain calcium and are sensitive to acidic materials. There are basically two tests that are normally used to confirm the material in question: an acid test and a hardness test. Tests should always be performed on an inconspicuous area.
Acids attack calcium-containing stones and etch the surface. If the surface is polished, the acid etch is more noticeable than with textured or honed surfaces. Providing that there are no coatings on the surface of the stone in question, a simple acid test may be all that is required to determine whether the stone contains calcium or not. Simply place a drop of acid in an inconspicuous area and observe the reaction. If the drop fizzes (effervesces), the stone contains calcium. If there is no reaction, the stone does not contain calcium and is probably granite, slate, sandstone, or quite possibly some type of ceramic tile made to look like natural stone.
The second test is also easily implemented. Using a pocketknife (Mohs hardness of between 6-6.5), pull the tip across the surface of the material. Marble is typically between a 3 and 4 on the Mohs hardness scale. Friedrich Mohs basically said it takes a higher number to scratch a lower number. 1 is talc and 10 is diamond. Therefore, the marble should scratch easily with no added pressure. Granites are normally around a 7 on the scale and should not scratch with the knife.
Next, determine what the expected results should be of the material in question. Is a highly polished surface desirable? Is slip resistance a major concern? Don’t forget economics and ease of maintenance. What was the original intent of the design? All of these issues should be of concern when designing a maintenance program for natural stone. There are three basic types of stone surfaces: 1) polished, 2) honed, and 3) textured. Many times I have seen a honed (smooth finish with little or no light reflection) limestone floor where the facility management insisted on a high gloss appearance. The easiest way this was possible was to use a topical finish to achieve the look they thought the stone should present. This usually results in failure both with respect to the expected appearance and cost. It could also be detrimental to the integrity of the stone.
Through years of experience and technical evaluation it has been found that, in most all situations, it is always much easier, more cost effective, and results in a better appearance to maintain the stone in its original condition rather than a coating on the surface.
Rules of thumb: 1) never try to make a stone something it is not; 2) whatever finish is desired, it is not poured on top from a bottle; and, 3) realize that stone is a product of nature and is admired for its inconsistencies and imperfections. These random patterns are what make marble and other natural stones so desirable.
Maintenance on calcium containing stones and non-calcium containing stones is identical, except with respect to re-polishing. Marble is normally a softer material than most granite and therefore develops wear patterns faster. And because it contains calcium, marble is also more susceptible to chemical attack. However, it is also much easier to restore the polish to marble than to granite. Because marble will etch, we can actually use products that contain special acids to aid in the polishing step the same way it is done at fabrication plants worldwide.
Superfine abrasives mixed with either potassium oxalate or oxalic acid will polish most marble, limestone, and terrazzo very quickly and efficiently. These marble polishing compounds and powders are available in ready-to-use formulas and can be used with conventional equipment to restore traffic lanes and areas where the natural polish has been degraded.
There is also another method of polishing that can add additional gloss called crystallization. This method typically uses a #0 steel wool pad to apply and buff the crystallizer. It is especially helpful with green (serpentine) marble and darker stones. It generally can’t make a bad floor look good but can make a good floor look better.
When the floor has deteriorated to a point where powders, compounds, or crystallizer no longer work effectively, it will probably be necessary to have the installation restored mechanically.
Granite polishing compounds are also available but since granite is acid resistant, these compounds can’t use the advantage of an acid. Therefore, granite must be polished mechanically using only superfine micro abrasives. It is a very slow process compared to the re-polishing of marble.
One of the most desirable traits of natural stone is that, in most situations, it is completely restorable. A mechanically restored floor is actually more valuable and desirable than a newly installed floor. A properly restored floor has no lippage (uneven tiles), looks better, and is easier to clean. Because it is easier to keep clean, polished surfaces will last longer with less frequency of re-polishing required. All stone flooring in Europe is ground flat when it is installed for these reasons.
With improved diamond technology and equipment, mechanical restoration projects are much quicker than those of 20 years ago. Restoration projects should be amortized over at least a five year period when justifying the cost. Maintenance costs will go down, appearance levels will go up, and trip hazards will lessen. All of these factors must be calculated in the cost. Attending an acknowledged restoration and maintenance training seminar will help the contractor learn this process and also help with confidence levels.
All natural stone has a porosity factor. Some stones absorb stains faster than other stones therefore, it is recommended that all stone be impregnated. Use of a high quality impregnator can only help an installation by facilitating much easier and more cost effective, long-term maintenance. Soiling and staining are much easier to remove and etching is much easier to restore on marble, which has been impregnated. Unlike topical coatings, true impregnators will not appreciably affect the natural qualities of the stone. The original permeability of the stone can remain as high as 97% when impregnated with a top quality product and the appearance of the stone should not be appreciably affected. An impregnator can be chosen for its water resistance or water, grease and oil resistance. This is a highly advisable optional step and definitely a win/win situation.
Use of a quality stone soap or quality neutral cleaner is probably one of the most important parts of any natural stone-care program. A stone soap will actually clean and enrich natural stone, rendering it more soil and stain resistant while keeping the natural colors bright and vivid. On darker materials, a quality neutral cleaner with optical brighteners may be the answer. Many contractors, who try to cut costs by using less expensive generic neutral cleaners, end up spending more time and money trying to keep the stone clean and usually the stone’s appearance factor suffers as well.
A periodic, thorough, intensive cleaning using an appropriate non-abrasive brush is recommended on a quarterly basis for commercial situations. This will clean the stone and grout lines of any stone soap accumulation. This is very necessary, as dirt tends to accumulate in the grout lines even with the best maintenance program in place. This intensive cleaner should also be used for extremely dirty situations.
Other products are also available for countertops, vanities, and vertical surfaces. This is where the importance of establishing a good relationship with a reputable distributor of products and technical support comes into play. There will be circumstances that arise where other specialty products may be needed such as stain removal poultices, adhesives for repair, and equipment. It is best to find a distributor who understands and supplies products to all phases of the stone industry. Even with the best of maintenance programs in place, there will be special situations that require some thought and expertise. Impregnators and stone soaps do not make stone bulletproof.
Terrazzo Floor Care
There are two basic types of terrazzo, cementitious and epoxy. Both refer to the matrix of the terrazzo. This means that usually terrazzo is made up of either cement and marble chips or epoxy and marble chips. There is poured in place terrazzo and pre-cast terrazzo which is usually available in 12˝ tiles. Poured terrazzo usually has either brass or zinc (silver colored) metal strips that divide a specific sized area.
The typical procedure for terrazzo (poured) is to pour in place, grind to a 100 or 120 grit, then seal with an acrylic or urethane sealer. When the original terrazzo sealer becomes worn, janitorial contractors begin the wax and strip programs. Natural polishing, like marble, is the latest technology for terrazzo floors. This type of procedure will improve the appearance and reduce the maintenance costs.
The terrazzo is stripped to remove any existing coatings, the honing procedure is then continued from where it left off, with diamond discs normally starting at about a 220 grit, depending on the condition of the terrazzo. The terrazzo is honed at least through 400 then 800 grit and finally taken to a high natural polish using polishing compounds. If a higher sheen is desired, the terrazzo can be crystallized, once dry.
Crystallizer is a spray and buff fluorosilicate acid used for the polishing of calcium containing materials. Epoxy terrazzo may require honing to higher levels, up to 3,500 grit, and followed by using a polishing compound and/or crystallizer. The resulting floor is much clearer in appearance, will not scuff, will never require stripping and re-coating, and should never discolor or yellow.
Maintenance consists of dust-mopping, routine damp-mopping or auto-scrubbing with a stone soap, and re-polishing of traffic wear areas as they develop with the polishing compounds and/or crystallizer. This approach looks better and costs less, it’s a no-brainer!
Suppliers should note that if they have the finish business now, their product sales should approximately actually increase with a naturally polished program. Cost reduction is from lowered maintenance hours not product. If they do not have the existing finish sales, they can effectively offer this new and improved program to acquire the business.
Ceramic Tiles
Grout lines are the weakest link with most ceramic tile floors. There are specific intensive grout cleaners available which, when combined with the right multi-level brush, will restore even the most grungy grout lines. Be aware that acids are to only be used as a last resort to clean grout lines as the acid will weaken cementitious grouts.
Commercial restroom floors are typically the 2˝ porcelain tiles. Facility managers are notorious for wanting these floors to have a high gloss. Until recently, the only way to accomplish this was with the use of floor finish or some type of coating. This procedure would almost immediately fail because the finish would not adhere properly to the tile, and is also hygienically incorrect, and eventually becomes unsightly and too costly to maintain.
Now there are two-step polishing powders for these porcelains as well as the quarry tiles, which will give the tiles a natural high gloss appearance with no coating. This procedure has high closure rate after a demo is completed.
Coupled with rates of $2.50 per sq. ft. or more, contractors love it! This naturally applied gloss will last many years, even in high traffic areas.
Once the tiles have been polished and the grout lines have been cleaned and restored, the grout should be impregnated (sealed) to prevent liquid contaminants from penetrating.
After the grout has been properly protected, the floor is now ready for routine maintenance, which should consist of a quality neutral cleaner. This is the closest thing to a Kevlar floor that can be achieved.
Other ceramics, such as glazed tiles, Mexican Pavers, terra cotta, etc. require slightly different care procedures. The key is to always clean and protect the grout and seek technical assistance when in doubt about the tile itself.
Contractors should contact a distributor that is knowledgeable in all of these areas to purchase their Super Hard Floor Care product lines. Superior technical support is the key to success when dealing with Super Hard Floors.
Bob Murrell has worked as a supplier of products and technical support to the natural stone industry, for over 35 years. He has written numerous articles for various trade publications and has also trained thousands of contractors over the past 25 years.