Stained Concrete Flooring Finishes
Stained concrete is the most common type of concrete finish because stained concrete is the most versatile. Stained concrete installation can be on both freshly poured and existing slabs to achieve a wide variety of finishes for residential and commercial facilities.
What is Stained Concrete?
While an oversimplified, stained concrete is a concrete slab with some color added to its surface. The complexity of this topic comes from the fact that there are several different categories of concrete colorants, each with ideal installation settings and various downsides and benefits.
Unlike paint or other concrete coatings, concrete stain penetrates the surface of concrete, leaving a finish that’s unlikely to chip or scratch. Like wood stains, most concrete stains are semi-translucent, allowing you to see the natural beauty and variation of the concrete surface through the stain color. Installations for concrete staining can often be quick and at a cost similar to or lower than most other flooring options.
Types of Concrete Stain
Acid Stain
Acid stain is the oldest and most prevalent style of concrete stain. For most people, an acid stain is what they picture when thinking of a decorative concrete floor. The acid stain has been used for over 100 years and is ubiquitous in commercial and residential concrete flooring, installs-especially for achieving brown concrete floors.
Acid stains are composed of water, muriatic acid, and metallic salts. Acid stain chemically and permanently modifies the color of concrete by reacting with calcium on its surface. Metallic particles are permanently bonded to the calcium in the concrete, creating the stained concrete floors we’re used to seeing.
Acid stains are penetrating, creating a colored surface that’s completely resistant to ultraviolet light. Because of this, an acid stain is the best concrete stain to use on an outdoor surface. Other styles of concrete stain may fade or discolor from exposure to sunlight. Acid stains are durable and often utilized in high-traffic areas without the risk of chipping or peeling.
Acid stain generally has a variegated or marbled appearance due to varying amounts of lime in the concrete surface. When installing darker stain colors, an acid stain can effectively cover imperfections in concrete surfaces—frequently used in loft-style apartments or rustic commercial renovations where a concrete slab is worn or many decades old.
The primary limitation of an acid stain is that it’s available in a limited variety of stain colors. These stain colors include earth tones, black, light blues, and greens. Further, acid stains may need up to 24 hours to react fully with the concrete surface, which can be prohibitively long for some projects.
An acid-stained floor must be coated with a sealer to protect it from foot traffic. Solvent-based acrylic sealers are most commonly used in exterior applications, while water-based polyurethane sealers are best for interior installs.
A cola acid-stained Craftsman Concrete Floor is a variety of concrete stain that offers natural colors with a marbled look.
Water-based Stain
Water-based concrete stains are a newer style of concrete stain and work by depositing fine pigments onto concrete surfaces. Unlike acid stains, they’re available in a full spectrum of colors. Further, as they don’t react with the concrete surface as acid-based stains do, water-based stains can offer color with a uniform appearance. Water-based stains create intricate designs or add a corporate logo to a concrete floor. Due to their potential for opacity, water-based concrete stains are the best choice for producing consistent, solid-color stained concrete floors.
While they’re considered UV stable, they’re less durable than acid stains and aren’t used as much on outdoor concrete.
A high-quality concrete sealer is required when applying a water-based concrete stain. Stained concrete sealers should require periodic inspection and re-applied when needed to prevent stained concrete floor failure in high-traffic areas.
Another benefit of water-based concrete stains is that they have no odors or VOCs that dry quickly. It can significantly benefit live-in residential renovations or overnight stained concrete floor touch-ups in retail installations. Below is a standard water-based stain color chart.
Concrete Dye
Concrete dyes are a type of concrete stain made from ultra-fine pigments suspended in solvents. Unlike acid concrete stains, they’re not reactive to the concrete surface. They offer the most transparency and natural appearance of any concrete stain for tinting, polishing concrete, or concrete overlays.
Solvent-based concrete dyes are very uniform in their stain color but require skilled installers as their short dry time leaves little room for error. Concrete dyes are not UV stable and, therefore, cannot be used for outdoor installations. Concrete dye, however, can add a very natural-looking hint of color to interior concrete floors and is available in various stain colors.
Integral Concrete Color
Although not technically a concrete stain, integral color is pigment added directly to a concrete mix before it’s poured. While this technique is only for new construction, it provides benefits that are not possible with a traditional concrete stain.
The main advantage of integral concrete color is it’s homogeneous throughout the slab. As a floor wears and ages, the color will stay consistent. Further, all the variations in the surface of the concrete are still visible, providing a modern appearance that rivals natural stone floors.
Another benefit of integral color is that it’s UV stable, so it’s exceptionally well suited for outdoor stained concrete floor installations such as patios and skim work. The essential pigment does not require a sealer to prevent fading, so it’s generally the best option for surfaces, such as pool decks, that would become slippery when wet if sealed.
The main drawback of integral pigment, besides the fact that it can’t be installed on existing concrete, is that it can increase the cost of a concrete pour by as much as 20%. However, depending on the project, this cost may be offset because there’s no additional labor expense to install the stain after pouring the concrete.
An integral color craftsman concrete floor, and you will notice how all the natural variegation in the concrete surface is still visible after a high-gloss polish.
Another Consideration — Surface Preparation
While many DIY-capable homeowners consider installing stained concrete floors themselves, proper surface preparation of concrete is essential, especially on older slabs.
We usually prep new construction with a swing buffer before staining for acid and water-based stains, but older slabs will likely require a planetary concrete grinder.
Only a professional should install acetone-borne concrete dyes on polished concrete floors. Mainly because of dust control and flammability issues, and suggest that DIY’ers avoid this installation.
Looking for more Information About Stained Concrete Floors?
Our primary stained concrete page has resources and galleries to help you learn more about stained concrete floors. As always, give us a call for a free consultation.