Exposed Concrete From The Start

Concrete floors can be integrally colored or stained, scored or not. Integrally colored concrete floors are of more uniform surface and color appearance, while stained floors are multi-hued, variegated and mottled, appearing aged and sometimes even “leathery”. Regardless of what the final decorative outcome is, it is most important to discuss your desire for exposed, finished concrete floors with your architect and builder.

It will be necessary to afford the concrete much more care and protection throughout the construction phases than it would be if they were to be covered by tile or carpet. It is imperative that the builder plan to place a moisture vapor barrier prior to pouring the slab in order to help reduce the possibility of moisture issues within the slab which may interfere with the final finish and, possibly cause the necessity for extensive, and often costly refinishing/replacement procedures.

It is also very important to plan for landscaping with excellent drainage around and away from the slab.

In addition, it is critical to note that everything that comes into contact with your concrete has the potential to leave behind a “chemical fingerprint”. In most instances this will cause a permanent, irreversible “shadow”, regardless of the use of the most aggressive stripping and degreasing methods, and which may or may not be visible until after the final finish has been applied to the concrete.

Oils, paints, plaster, dry-wall mud, and treated lumber, are only a few of the biggest culprits within the construction and/or remodeling industry for affecting the finished appearance of exposed concrete, most particularly acid stained concrete. Tape and chalk (particularly red) will permanently and irreversibly damage the concrete surface.

Finishing Options

We are noticing a trend recently which we have called “industrialization”, in which new and old concrete slabs are stripped and/or finished just as they are, leaving flaws such as scarring, carpet tack patching and inherent discoloration as they are, and achieving what is described as a cold and “industrial” appearance. This can actually work to ones advantage, especially for those who have new concrete and prefer to have a very neutral gray color on the floor, which is easy and versatile and very conducive to frequent decorative change.

On the other hand, there are two general types of stain. Acid stains consist of stains that are suspended in acid. The acid “opens up” the surface of the concrete and allows for deeper, permanent penetration of the colorant. Unlike paint and polymer based stains, acid stains react with the minerals already present in the concrete, giving it the look and feel of natural stone or leather. Each concrete installation is as individual and unique as a fingerprint and accepts stain treatments in varying degrees of intensity, creating multi-hued color variations and an uneven surface that appears aged and mottled.

We use Kemiko brand acid stains because they are permanent and extremely durable. Kemiko acid stain colors will not fade with time and are most effective at withstanding heavy foot traffic, particularly in commercial settings, weathering and extreme ultraviolet exposure. In addition, acid-based stains tend to keep small nicks and minimal dings from showing through as gray, raw concrete. One of the minor draw-backs to acid stains is that the color palette is rather limited. In addition, because of the various chemical “unknowns” inherent in every individual slab, the colors you see on the white background of a brochure are only “ballpark” ranges. Most acid stains result in a wide variety of color, tone and hue ranges.

Polymer based stains are considered more a topical colorant. There are a couple of very high-quality brands on the market, one of which is made by Kemiko, called Rembrandt. Another is Super-Krete Color Stain. Both are semi-permanent and fairly durable, particularly in indoor settings. One of the great advantages of this type of stain is the availability of a wide range of colors and decorative possibilities.

One of the minor drawbacks to this type of stain is that, because it is more of a topical treatment, even minor nicks and scratches may result in the exposure of the underlying gray concrete, requiring touch-up treatments. In addition, these stains may be more susceptible to damage and deterioration from more caustic spills, as well as being “walked off in higher traffic areas, particularly in home settings in which regular annual professional maintenance is not practiced faithfully.

In either case, one of the key issues with any stain is that any cracks or areas that have been patched or repaired, previously covered by tile or other floor coverings, previously stripped of adhesives and cure agents, or fiber reinforced, will accept the stain to a different degree than the rest of the concrete, possibly resulting in the more prominent appearance of patches and chemically treated areas. This does tend to be a drawback more often with acid stains than polymer stains, although, either way you play it; it is always a game of chance.

This brings us to the possibility of resurfacing the slab. The “overlay” process consists of troweling a “credit card thin” layer of concrete over the existing slab. This is highly recommended for those who prefer a newer, more uniform surface appearance.

One of the great advantages of this treatment is that it allows for integral coloring of the resurfacing medium in a wide range of colors. This allows for a more uniform appearance with regard to the color, as opposed to the multi-hued, mottled effects created with stains.

For those who appreciate the special effects of stains, but not the appearance of patching, chemical scarring and other imperfections which may be highlighted by stains, there is always the option of staining the resurfacing medium.

It should be noted that resurfacing comes with its own brand of quirkiness. For instance, trowel marks, which are naturally inherent trait of any concrete installation, lend their own brand of character to the treatment. In addition, cracks within the underlying slab are usually a naturally occurring result of settling and slight seismic activity deep within the earth and occasionally transfer through the resurfacing medium, resulting in the need for further cosmetic attention.

The long-overdue and most highly recommended treatment for new and existing concrete slabs is polishing.

This process is one in which different grades and types of abrasives are used to hone and then polish the surface of the concrete slab to a beautiful sheen. Done in conjunction with the use of densifier/hardeners, this process eliminates the need for application of topical sealants, and virtually eradicating the headaches associated with moisture issues, which are inherent in all concrete applications. This particular procedure may be marginally more costly in the beginning; however, the savings with regard to refinishing and maintenance in the long range are quite significant.

This process can also be combined with acid staining to create an absolutely beautiful, naturally aged, stone-like appearance which is permanent and easily cared for.

We currently average anywhere from 18-36 residential stain and resurfacing treatments per year and that number seems to be increasing. Prices for such projects can fall within a wide range and are determined by factors including, but not limited to, the condition of the existing slab, total square footage, and type and extent of preparations required.

In addition, such treatments require that the immediate work area be vacated for the average duration of 5 working days, with complete restriction of foot traffic for the duration. This generally applies to all projects, regardless of total square footage. While the cost of such treatments may or may not be comparable to other floor covering options, these treatments can be more versatile and durable.

The commercial locations listed below are open to the public and available for you to look at various stain and resurfacing projects which we have worked on over the years. It is important to note that these projects have been done at various times over several years, and that, in many commercial settings, traffic and wear levels are much higher than in the residential setting, and floors are not necessarily maintained according to ideal standards.

When viewing these settings, please take note of the depth and various hues accomplished, as well as the mottled, aged, almost leather-like appearance. The latest in sealing technology and products also allow for wide variation as far as shine level and color enhancement of the finished concrete floor.

Introduction of decorative scoring and bordering also add to the beauty and versatility of the acid staining effect. Our acid stain guide provides more details regarding these effects, and both guides should give you a good idea of what to expect as far as staining results and care and maintenance thereafter.

Tucson Area Concrete Floor Examples

Please feel free to visit the following locations for further staining ideas and color representations, keeping in mind, however, that all concrete stain projects are as unique as the chemical fingerprints of the slabs themselves.

• Vero Amore Restaurant, 3305 N Swan Rd, # 105: Dining area: black acid stain border w/ lighter Black and Cola in checkerboard center. Rear and bathroom in Black only. This project made up of slabs of varying ages with multiple re-pours and patching.
• Mendoza-Cipollo Family Chiropractic office, 3925 N First Ave, (Black – very old slab, formerly covered by carpet and tile. It is very hard to believe that this is black stain, and it is a good representation of the extremes which are possible with acid stain)
• Backfire Chiropractic office, 330 E Prince Rd, (Overlay, saw-cut pattern, stained Black and Cola. It was resurfaced due to condition of slab beneath which was originally covered by carpet and vinyl, Very good example of texture levels which are expected with overlay)
• The Nature Conservancy of Arizona, 1510 East Fort Lowell Road (Aqua Blue and Green Lawn, stained existing slab)
• Studio C, 11085 North Oracle, Oro Valley: This setting is an example of polished concrete, acid stained in Malay Tan. It should be noted that a much shinier result may be achieved, depending on personal preference.
• Dorado Designs Showroom, 12490 North Rancho Vistoso Blvd. (new slab, ground to expose aggregate, stained Black, the other areas stained Golden Wheat)
• California Design Center, 3700 East Fort Lowell Road (Cola)
• Beth Friedman Collection, 1865 East River Road, Suite 121 (stained existing slab, Malay Tan)
• Ra Sushi, La Encantada Mall, 2905 East Skyline Drive (overlay with integral color)
  (Please note that most of the existing exterior concrete has also been stained in various colors.
  This work was done by our very good friends at Casa Custom Floor Care)
• Residential project: 8502 East Colette St: Driveway acid stain

Please don’t hesitate to give us a call at 272-0815 with any further questions or concerns you may have regarding your upcoming project. We look forward to hearing from you!!