Concrete Polishing & Staining
Polished Concrete Basics
How to Polish ConcreteSimply put, polishing concrete is similar to sanding wood. Heavy-duty polishing machines equipped with progressively finer grits of diamond-impregnated segments or disks (akin to sandpaper) are used to gradually grind down surfaces to the desired degree of shine and smoothness.
The process begins with the use of coarse diamond segments bonded in a metallic matrix. These segments are coarse enough to remove minor pits, blemishes, stains, or light coatings from the floor in preparation for final smoothing. Depending on the condition of the concrete, this initial rough grinding is generally a three - to four-step process.
The next steps involve fine grinding of the concrete surface using diamond abrasives embedded in a plastic or resin matrix. Crews use ever-finer grits of polishing disks (a process called lapping) until the floor has the desired sheen. For an extremely high-gloss finish, a final grit of 1500 or finer may be used. Experienced polishing crews know when to switch to the next-finer grit by observing the floor surface and the amount of material being removed.
During the final polishing step, some contractors spread a commercial polishing compound onto the surface to give the floor a bit more sheen. These compounds also help clean any residue remaining on the surface from the polishing process and leave a dirt-resistant finish.
Polished Concrete versus Other Flooring MaterialsBy Anne Balogh, The Concrete Network
Decorative polished concrete offers a number of advantages that other flooring materials can't match, particularly when it comes to durability, performance and sustainability. Here, we compare polished concrete floors with some of the alternatives.
|Wall-to-wall carpet||Ceramic tile||Vinyl or linoleum||Wood or wood laminate||Natural stone (such as slate or marble)||Polished concrete|
|Available in a wide spectrum of design options||Yes||Yes||Yes||Yes||No||Unlimited|
|Longevity and performance||Poor||Good||Good||Good||Excellent||Excellent|
|Ease of maintenance||Poor (needs frequent vacuuming; stains easily)||Good||Good (linoleum may need occasional waxing)||Good||Good (linoleum may need occasional waxing)||Excellent|
|Can radiate heat and store solar energy||No||No||No||No||Yes, depending on the material||Yes|
|Vulnerable to humidity and moisture damage||Yes||No||Yes||Yes||No||No|
|Can harbor mold, mildew, dust mites and other allergens||Yes||No||No||Yes (mold and mildew, if the flooring becomes wet)||No||No|
|Is a sustainable flooring alternative||No||Yes||Maybe (if using linoleum made from all natural materials)||Maybe (if made from reclaimed or FSC-certified wood)||Yes||Yes|
|Average cost per square foot installed||$3.38 - 6.61*||$11 - 22*||$2.64 - 5.64*||$8 - 10||$20 - 50+||$3 - 7 (for a 3,000-grit finish and the use of an impregnating sealer)|
|Average lifecycle cost||High||Low||Intermediate||Intermediate||Low||Extremely Low|
Maintaining the Shine
Although keeping polished concrete shiny requires minimal effort and expense, some regular care is necessary.
Demmert and Associates in Glendale, CA
Demmert and Associates in Glendale, CA
Demmert recommends a simple maintenance program of occasional dusting to remove grit and damp mopping with a neutral cleaner to enhance the shine. Some manufacturers sell special cleaners and conditioners for polished concrete that not only clean the surface, but also leave behind a dirt-resistant film. These products can be applied with a mop or auto scrubber and do not require buffing.
With basic cleaning, polished concrete should keep its luster for years. Eventually, though, the shine can dull, especially in high-traffic areas. Fortunately, its easy to restore the gleam. Sometimes simply buffing the floor with a commercial polishing compound will do the trick. If more touch-up is necessary, the floors can be lightly repolished with a fine-grit abrasive.
Polished Concrete ApplicationsBecause polishing is a multi-step process, customers can choose the level of sheen from satin to high-gloss that meets their maintenance and aesthetic requirements. This versatility makes polished concrete an ideal flooring material for a variety of applications. Polishing contractors say their primary customers include:
- Large warehouses and warehouse outlets
- Retail stores
- Hotels and restaurants
- Office buildings
- Auto showrooms
- Private residences
Ease of maintenance is the key reason many warehouses and retail facilities are opting for polished concrete. Not only are polished floors easy to clean, requiring only occasional damp mopping, they hold up well to heavy forklift and foot traffic. They also eliminate the need for messy waxes or coatings as well as the associated labor, time, and expense to apply them. Once more, the glossy surface resists the marks of forklift truck tires and staining from oil and chemical spills.
The high light reflectivity of polished concrete is another important benefit, especially for office buildings, hotels, restaurants, and other public facilities that want to project a bright, clean, professional image. "Some customers simply want a look that's unique," according to contractor Doug Demmert of Demmert & Associates, Glendale, Calif. (see Company Specializes in Polished Concrete Finishes). He says that polishing can give concrete a higher degree of shine, similar to polished marble or granite, than can be achieved with a high-gloss coating. This makes polished concrete a particularly good alternative for homeowners or businesses that can't afford marble or granite floors but want the same brilliant, mirror-like finish. To replicate the color of stone, Demmert will sometimes apply stain to the concrete during the polishing process or polish concrete that has been integrally colored. It's also possible to produce a terrazzo look by grinding through the top few millimeters of the concrete surface to expose the aggregate.
Yezco Decorative Concrete in Phoenix, AZ
Yezco Decorative Concrete in Phoenix, AZ
Can Polished Concrete Be Slippery?Kept clean and dry, polished concrete floors are generally no slicker than plain concrete surfaces. And they tend to be less slippery than waxed linoleum or polished marble.
But public facilities that want to provide extra protection against slip-and-fall accidents can treat polished floors with anti-slip conditioners. These products contain special additives designed to improve traction and make wet surfaces safer. They must be reapplied periodically, but they can simply be mopped on during routine cleaning.
Designing with Polished ConcreteStains and dyes are the most popular applications for enhancing already existing polished concrete. Other options include scoring and creating radial lines, grids, bands and borders, and other designs.
If the decision is made to polish concrete in advance of the concrete being poured, there is a stunning array of available options:
Artistic Surfaces Inc. in Indianapolis, IN
- Colored aggregate can be applied to the concrete mix or seeded into the top layer of the mix. The polishing process will reveal these aggregate.
- Integrally colored concrete can be used.
- Glass can be seeded into the mix. The polishing process will reveal the glass pieces.
- Nails, bolts, computer chips, or any other objects can be seeded into the mix and then polished smooth.
- Of course, any of these options can be combined together or into a pattern.
Not Polished, but Still AwesomeAs noted earlier, polishing concrete required a series of polishing steps culminating with the use of 1800-3500 grit diamonds. Each step in the process increases the shine and reflectivity of the concrete.There are other options, which though they stop short of 1800-3500 grit diamonds, are still beautiful.
Two steps of grinding to expose the aggregate, then applying a topical sealer, might be called the exposed aggregate, sealed look. While still taking on a polished look, the polish is a result of a topical coating (still beautiful, but requiring more maintenance).
Demmert and Associates in Los Angeles produces a finish they call a honed finish where they stop at 220 grit diamonds. This honed finish has some surface shine, but is still smooth and easy to clean.
Demmert and Associates also lets customers review the floor at the 400-800-and 1800-grit diamond level of shine if the customer is unsure if they want a fully polished look (though most clients do want the floor fully polished).
Clearly, there are many levels of floors that stop short of truly being polished concrete, but are beautiful in their own right.