Concrete flooring works well in bathrooms for the same reasons that ceramic tile is so ideal for the same space—it's easy to clean and it can't be damaged by water. Not surprisingly, the same drawbacks associated with ceramic tile also apply to concrete. Concrete can be cold, and it can be slippery if it has the wrong type of finish or surface treatment. Concrete is also very hard, but this is a less significant drawback in the bathroom than it is in other living spaces.
The simple ground-and-polished plain concrete flooring surfaces that were once standard are now giving way to much more diverse installations of dyed, acid-stained, or textured concrete that give these floors much more diversity. Once relegated to homes with a modern, industrial aesthetic, concrete floors can now be given treatments that allow them to be used in many different home styles.
|Excellent water resistance||Slippery when wet|
|Very durable||Cold underfoot|
|Easy to clean||Easily stained unless sealed|
|Less expensive that luxury tile||Hard surface is unforgiving in falls|
|Excellent for modern decor|
Nationally, a basic polished concrete floor with one layer of stain averages $3 to $8 per square foot, while more elaborate designs or texturing will cost $5 to $15 per square foot. In above-grade locations where a cement-board underlayment or structural reinforcement is required, you can expect costs to increase by $2 to $3 per square foot.
While these costs are at the upper end of most flooring materials, when you consider that the floor is likely to last as long as the house itself, concrete flooring becomes a remarkably cost-effective choice. While professional concrete installers typically guarantee their work for 20 years or so, with proper care, a concrete floor can easily last for the lifetime of the home. Given this longevity, concrete is one of the more cost-effective flooring materials you can install. Other premium floorings are typically replaced every 10 to 20 years, while you may never need to replace a concrete floor.
Maintenance and Repair
Concrete scores very highly in the cleaning and maintenance category. Aside from periodic sealing of the surface to prevent stains, concrete is effectively maintenance-free. For everyday cleaning, you can sweep, vacuum, dry-mop, or wet-mop as much or as little as you like. Concrete is not like hardwood or carpet, which wear much faster without regular cleaning. Just be careful with cleaning agents, as some cleaners may react chemically with the concrete and cause discoloration.
No amount of water can actually damage a concrete floor. This means you never have to worry about wet feet, damp towels, shower spray, or spills from the sink or tub. While the material itself is immune to damage from water, if concrete flooring develops cracks, it can allow water to pass through to whatever material is underneath. This can be a problem if the floor is laid over a cement board and plywood underlayment since water can seep through and cause moisture damage. Thus, it's important that you regularly examine a concrete floor for cracks and patch them when they develop.
Concrete flooring still tends to work best in modern home designs, especially those favoring an industrial aesthetic, though newer texturing and coloring techniques make concrete a possible flooring material in other home styles, as well. Where a high-quality finished flooring surface is required, the concrete slab may be stained, polished, painted, or top-coated to make for a unique and attractive floor.
Concrete can be colored by adding dye to the wet concrete as it is being mixed, or by staining/etching it with acid or other substances. And concrete can be stamped with stencil patterns to give it texture.
Concrete Floor Installation
Concrete bathroom floors are most commonly found in homes with slab foundations or in basements, where the floor already consists of a 4- to 8-inch concrete slab that rests directly on the soil. If the existing slab is in poor condition, a thin concrete overlay can sometimes be poured over the slab to create the perfectly smooth surface necessary for grinding and polishing. This overlay can be paper-thin, or an inch or two thick, depending on the needs. Overlays are not possible, though, if the slab is in very poor condition or actively heaving.
If concrete is being considered for an above-grade floor, then its heavy weight creates some unique considerations, since standard joist platforms may not be strong enough to support the live-load of a concrete slab. The installation is so complicated that concrete floors are rare in above-grade situations, except in apartment buildings or other steel structures. In the rare event that a concrete floor is installed in a standard wood-framed home, it generally involves framing the floor platform with extra-strong joists and beams, installing some sort of cement-board underlayment, then pouring a thin slab of concrete reinforced with a mesh of rebar.
Pouring a full slab or overlay, followed by grinding and polishing, and concluding with staining or dying, is a process that requires special skills and equipment. Concrete flooring is not an option for DIYers.
Comfort and Convenience
Interior concrete floors can be finished until they have a very smooth, almost glass-like surface, and these floors can be very slippery when wet, especially if treated with a surface sealer, and especially when you are barefoot. Combine this slipperiness with a rock-hard surface and you have a problem surface for bathrooms, where moisture is the rule. If you're having a new concrete slab or concrete overlay poured for a bathroom floor, make sure the finishers leave it with a little traction for safety. Do the same if you're grinding and polishing an old concrete slab to use as a finished floor.
Concrete is a naturally porous material that is highly susceptible to staining from spilled liquids. The same characteristic that allows concrete to accept a decorative stain also makes it susceptible to discoloration from chemicals. Stains are less likely to occur in a bathroom than in a kitchen, but it's still a good idea to take precautions to protect the floor. The best solution is to seal the concrete periodically with a film-forming sealer. Some sealers also add a bit of traction to the floor, which is a good option if the floor is too smooth for safety in a bathroom.
Concrete slabs tend to be colder than flooring materials laid over wood subfloors, because the slabs typically sit directly on the earth, which absorbs heat. Concrete also has a high thermal mass. This means that a cold floor tends to stay cold and a warm floor tends to stay warm; in other words, concrete changes temperature slowly. If you're heating a bathroom with conventional forced-air heat, you're simply blowing warm air over the top of the floor and throughout the room, which has little warming effect on a slab that's also being chilled by the ground 24 hours a day.
On the other hand, if you're pouring a new concrete slab, you can pour the slab over insulation that serves as a thermal barrier over the ground, or install a radiant floor heating system to heat the slab and turn it into an actual heat source. Due to its thermal mass, concrete is an excellent material for in-floor heating. Radiant systems are available both as electric wire coils and as hydronic systems that circulate hot water through plastic tubing embedded in the concrete as it is poured.
Concrete Flooring vs. Ceramic Tile
Now that concrete flooring is often installed with various color treatments and textures, it no longer has the same enormous style deficits when compared to ceramic or porcelain tile. Still, ceramic tile continues to offer greater aesthetic diversity than concrete as a flooring material. Ceramic tile is a lighter material than concrete flooring, allowing it to be used throughout the house without additional structural modifications. Further, ceramic tile installation is possible for an ambitious DIYer; concrete flooring virtually always requires professional installation and finishing.
But concrete wins hands-down when it comes to sheer durability. Polished concrete floors can last a century if they are regularly sealed and well-maintained, while ceramic tile floors, while quite durable, generally need replacing within 30 to 50 years, at most.
Is a Concrete Bathroom Floor Right for You?
Concrete has some key features that make it a very good choice for bathroom floors, as well as some characteristics that make it problematic. It is a very durable, easy-to-clean, and waterproof material, but it is also a cold, hard, slippery surface that may make it problematic if you are worried about users falling. You'll need to weigh these pros and cons to decide if this flooring material is appropriate for you.