Plain concrete slabs have served as the flooring material for basements, garages, patios, and utility areas for many years, but concrete is now also a viable material in home interiors, where it can be polished, etched, or stained to serve as the finished flooring surface. If you are used to thinking of concrete as a utilitarian surface suitable only for utilitarian surfaces, the many virtues of concrete as a decorative flooring material may come as a surprise. Concrete can make some of the most elegant and colorful floors you have ever seen, though they aren't a good stylistic fit for every home.
A concrete floor is extremely strong and durable, and if it is properly installed and maintained, it can last for as long as you own the house. And the design options are remarkably diverse. But concrete is also very hard and cold underfoot, and it is a practical choice only where there is an existing concrete slab, such as in homes with slab-on-grade foundations, or in the basements of homes built over basement foundations. Since these floors on "on-grade"—directly contacting the soil—they can be susceptible to moisture migrating up from the ground into the living space.
Easy to maintain
Hard and cold
Susceptible to moisture
Concrete Floor Cost
The installed cost for a concrete floor can vary quite a lot since there are so many finish options. Costs can range from $2 per square foot for a basic to $30 or more for high-end artistically rendered floors.
- Basic design: $2 to $6 per square foot. A basic concrete floor design includes pouring the slab or overlay, then a basic polishing and single colorizing treatment (staining or dyeing).
- MId-range design: $7 to $14 per square foot. This price range includes pouring the slab or overlay, then polishing and staining with multiple colors.
- High-end design: $15 to $30 per square foot. The most sophisticated (and expensive) concrete floors can include creating geometric patterns in the slab or overlay, as well as multiple colors and a variety of texturizing or stamping techniques. These are quite artistic floors.
A sealed and properly maintained concrete floor can last indefinitely. Even in commercial applications, concrete can survive under high-traffic conditions for many decades. Over the long run, this can save you a considerable amount of money and effort over replacing flooring every few years.
Maintenance and Repair
Concrete flooring begins with a structural concrete pad that is by nature extremely strong and durable, which is why it is so popular for hard-working commercial areas, such as garages and warehouses. Concrete has similar virtues when used as a residential flooring material. It is difficult to damage, and high heels, furniture legs, and pet claws won't scratch the surface. You also don't have to worry about damage from most dropped items. While it is possible to chip or scratch a concrete surface, you have to work pretty hard to do so.
Keeping a concrete floor looking its best is fairly easy. It needs to be sealed or waxed every three to nine months, depending on the level of traffic, in order to maintain the protective layer. Other than that, you can use a neutral cleaning agent to mop the floor clean periodically. A blue utility pad can be used for particularly stubborn stains.
Concrete floors can be susceptible to settling and cracking over time, and this is a more frequent problem when an existing structural slab has adapted to a finished residential flooring surface—such as when a basement or loft condo has been converted to living space. If the floor becomes badly cracked, it is possible to patch, grind, and refinish the floor to restore its sheen.
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Aesthetically, concrete floors are a good match for homes with a modern or industrial style and are less suitable for classic vintage home styles. A polished and acid-stained concrete floor will likely look out of place in a classic colonial-style home, for example, but fit quite nicely into a contemporary-style home.
The time when a concrete floor meant just a poured and polished slab is long since gone. While the simple polished slab is sometimes exactly what is needed, homeowners also have the option of a variety of texturizing and colorizing techniques:
- Overlay: This refers to a thin layer of new concrete laid over an existing slab to rejuvenate it. The overlay is then polished and colorized in the same manner as a new slab.
- Polish: A basic poured slab or overlay can be honed with progressively finer abrasive pads to create a glass-smooth finish. When a sealer is then applied, the result is a very attractive, shiny floor.
- Acid-stained: When treated with mild acids, concrete will interact to form a colorful mottled surface that has a marble-like appearance. Each floor is entirely unique.
- Dyed: Another method of colorizing concrete, dyeing is the application of a solid colorizing agent over the finished surface. Unlike acid-staining, dyeing creates a solid color effect.
- Texturized or stamped: While still wet, the concrete surface can be brushed, stamped, or embedded with glass beads or fine aggregate to give it a three-dimensional texture.
- Geometric divisions: High-end concrete floors are sometimes laid out with geometric patterns, with each segment colored or texturized in a different way for artistic effect.
- Stenciled or airbrushed: Concrete floors can serve as large canvases for a variety of artistic painting techniques.
Concrete Floor Installation
In most circumstances, a residential concrete floor is created by grinding an existing structural concrete slab and applying a chosen polishing, colorizing, or texturizing technique. This can involve first removing any existing flooring, such as carpeting or vinyl, to expose the existing concrete slab. Where the slab is in poor condition, a thin overlay of fresh concrete can be poured over the old slab; this overlay then becomes the base surface for polishing, colorizing, or texturing. Where a fresh slab or overlay is being poured, colorizing agents can be mixed into the concrete before it is poured. Otherwise, the staining or dyeing generally occurs after the concrete has been polished by grinding with abrasive pads with progressively finer grits.
The final step is to apply a concrete sealer to protect the surface. This treatment will need to be repeated at regular intervals; some experts advise a yearly reapplication.
While it is somewhat rare, it's also possible to install concrete flooring over a wood-framed subfloor. Here, the process involves pouring a thin layer of overlay concrete over a carefully prepared subfloor, then applying the chosen colorizing and polishing techniques. However, even a very thin concrete overlay is quite heavy, and the process often requires structural reinforcement of the wood framing.
Whether it involves pouring a fresh new slab, adapting an existing slab, or pouring an overlay, concrete floors are usually installed and finished by professionals, since the work is quite hard and requires special tools. Adventurous DIYers can rent grinders to hone a concrete slab themselves, though this is not recommended.
As long as the concrete is smooth and free from holes, bumps, and defects, you have the choice of covering it over with any floor surface covering you choose at a later date. Concrete floors allow you a lot of future design freedom.
The strength and durability of this material can also be a liability. The surface of a concrete floor is very hard—falling onto concrete will hurt and may seriously injure people. Items dropped on these surfaces are also likely to shatter or crack. That is why concrete floors are not recommended for areas that will be used by children or elderly people, or in kitchens where falling dishes are likely. The hardness of concrete also makes it uncomfortable to stand on for long periods.
When concrete is highly polished or buffed, or when coated with a gloss sealer, the surface can be very slippery, especially when wet. Concrete in bathrooms, kitchens, or entryways is especially susceptible to this. Another drawback of concrete is that it has little insulating value, and it will feel quite cold on winter mornings—unless it has been installed in conjunction with a radiant floor heating system. The inherent coldness of concrete can be offset to some extent through the use of carpets and throw rugs.
If not properly sealed on both top and bottom surfaces, concrete is easily penetrated by moisture when installed over bare soil. The cool temperature of concrete can also cause moisture to condense in humid conditions. If liquid does manage to make its way into the pores of a concrete floor, it can lead to the growth of mold or mildew in your home. In some environments, you will also have to worry about the moisture freezing, expanding, and cracking the floor.
Environmentally conscious consumers can feel good about finishing an existing concrete slab, since this requires no manufacture of fresh concrete. But those same homeowners have reason to be concerned about pouring a new slab or overlay, since the manufacture of concrete requires a significant expenditure of energy and copious amounts of carbon dioxide.
Is a Concrete Floor Right for You?
A concrete floor can be a good choice if you have an existing slab foundation and a home style that is a good stylistic fit for the polished gleam of honed concrete. Many people appreciate the low cost of concrete floor, especially when considering the long life this floor will enjoy—you may never need another floor covering. But be prepared for a floor that is very hard and naturally cold.
Hasanbeigi, Ali. Price, Lynn. Lin, Elina. Emerging Energy-efficiency and CO2 Emission-reduction Technologies for Cement and Concrete Production. China Sustainable Energy Program of the Energy Foundation through the U.S. Department of Energy, 2012.