We have to admit that a polished concrete garage floor can look fantastic. The natural concrete look with a mirror finish is stunning. As an option, add a concrete stain and a few well-placed decorative saw cuts during the polishing process and you can have a custom look and design that will be the envy of your friends and neighbors.
This begs the question though; is polished concrete truly a practical application for a garage floor?
You may have seen some of the features and benefits that are listed for polished concrete. Some of these benefits include stain resistance, good light reflectivity due to the glossy finish, easy cleaning and maintenance, a surface that is not easily damaged, and long life since the flooring never needs to be replaced. It typically is less slippery when wet than some other garage flooring options as well.
If you didn’t know any better, polished concrete seems like the best garage flooring option that you could choose. But is it?
Most, if not all of the stated features and benefits of polished concrete are true. However, you may be surprised to learn that a polished concrete garage floor is not as practical as you may think for many garage environments, though they can work well for some.
So, do we recommend polished concrete for your garage floor? Well, in order to better understand why it may or may not be good for your garage, it’s first important to learn the process of how concrete is polished.
How to Polish a concrete Garage Floor
Polishing concrete is not as simple as running a large buffing machine on bare concrete to shine it up. It is actually a series of many steps that include grinding, honing, and then polishing.
The process typically starts with a large planetary grinding machine using metal-bonded diamond grit discs.
It can start as low as a 16-grit disc and then work up in multiple passes to a 150-grit disc, though you can go higher in some cases. Each successive disc removes the scratches and grooves created by the previous diamond disc.
Which grit disc you start with is determined by how much aggregate you want to be exposed (if any) and what kind of shape the concrete is in initially. In other words, are there defects to be removed, waves in the concrete that need leveling, old coatings present, etc.
The grinding opens up the pores of the concrete. Once the last grinding pass has been made, the concrete is treated with a liquid densifier to harden the surface in order to aid the polishing process. A densifier may be added more than once depending on how hard or soft the concrete may be. Densifiers also aid in preventing water penetration and they help to resist staining of the concrete.
At this point, the honing process begins with the use of resin-bonded diamond discs. Honing will give the concrete a low satin sheen that begins to shine up with each successive step. You actually step down a grit when you start this process.
For example, if the grinding finished with a 150-grit metal-bonded diamond disc, you would begin the honing process with a 100-grit resin-bonded disc. Many times the first disc used in the honing process is a transitional diamond disc.
Honing then continues with 200, 400, and then 800-grit discs. It is during the honing process that a concrete stain can be introduced if so desired.
It is after the honing process that the true polishing of the concrete begins. It generally finishes with 1500 or 3000-grit diamond-impregnated pads. When polishing, the higher the grit you finish with, the higher the gloss of the floor.
It is after the polishing process that an optional stain guard can be applied to the surface of the concrete. The stain guard is a penetrating sealer with an ultra-thin topical coating that helps to protect the concrete from liquid chemicals, solvents, and staining.
Aggregate Exposure and Gloss Levels
When you decide to polish the concrete of your garage floor, you first need to decide on the aggregate exposure that you would like to see at the surface and then the level of gloss or shine that you require.
The aggregate exposure is measured as class A, B, C, or D. Gloss is measured as levels 1, 2, 3, and 4.
Aggregate class
- Class A is a cream finish that has little to no aggregate exposed.
- Class B is a fine aggregate of 1/16” – also referred to as a salt and pepper finish.
- Class C is a medium aggregate exposure of 1/8”.
- Class D is a large aggregate exposure of 1/4”.
Gloss Levels
- Level 1 is below 100 grit with a flat appearance and no sheen.
- Level 2 is 100 – 400 grit with a satin or matte appearance and low to medium sheen.
- Level 3 is 800 grit and higher with a semi-polished appearance and medium to high sheen.
- Level 4 is 1500 grit and higher with a highly polished look and sheen. It’s not uncommon to have a mirror appearance that may even look as though it is wet.
The video below is an excellent example of how these aggregate classes and gloss levels are applicable.
Now that you know how concrete is polished and protected, we will discuss who may or may not benefit from such a garage flooring option.
Why we don’t recommend polishing your garage floor
Yes, that is correct. After discussing how durable polishing can be, we don’t recommend polishing the concrete of your garage floor in most circumstances. Nevertheless, there are some people that are perfectly suited for such an option, as we will explain.
The reasons vary and have to do with factors. These include the climate where you live, the maintenance required from exposing the surface to vehicle traffic, and the fact that polished concrete does not do well to chemical exposure such as solvents, gasoline, and acids. Let’s explain.
We will start with climate first. If you live in an area of the country where it snows, your vehicle will be tracking in road salts and deicing fluids that collect on your garage floor. Polished concrete does not stand up well to a salty brine and will actually begin to lose its gloss. Road salts can even slightly etch the finish if left to linger long enough.
Of course, you can help to combat this with a winter containment mat if you like, but it will require diligence on your part to make sure that all winter liquids stay within the mat.
The next reason has to do with routine floor maintenance from vehicle traffic. Most polished concrete is exposed to foot traffic only, though there are exceptions. Light industrial applications where forklifts are used primarily indoors are an example.
Vehicles, on the other hand, track in much more dirt and debris from the roads. This includes small pebbles and sandy grit. If the floor is not swept or dust mopped on a regular basis, your vehicle tires can actually degloss the finish over a period of time in the areas where they consistently roll in and out of the garage.
Essentially, what the tires are doing is slowly sanding the finish of the concrete with a more aggressive grit than what the floor was polished with. Granted, this grit is not diamonds so it does take some time.
You can combat this fairly easily by simply keeping the floor clean. Maintaining polished concrete is simple due to the fact that it doesn’t take much to clean it. A dust mop is generally all that is required. Heavier cleaning can be done with the occasional wet mop using clean water only.
But what about the concrete I see in home improvement centers? They always look good and have high traffic.
Still, if you have a semi-busy garage, this cleaning maintenance needs to be done on a fairly consistent basis — much more than what you would expect to do with a typical garage floor coating, mats, or garage floor tile. Yes, you may see some vehicle showrooms and automotive centers with polished concrete. What you don’t see is the routine mopping of the floors that are done every night.
“But what about the concrete I see in home improvement centers? They always look good and have high traffic.” – Yes, they do. And most of that traffic is foot traffic. What you don’t see are the routine maintenance and auto scrubbers that they ride around on to keep the floor looking that way.
Lastly, polished concrete does not stand up as well to certain automotive fluids and can stain. Once polished concrete is stained, it is extremely difficult to remove the stain. Remember, polished concrete has open pores, though very small.
Thicker viscous fluids such as oil do fairly well against staining if cleaned up in a reasonable amount of time. However, anti-freeze coolant, brake fluid, and solvents such as gasoline do not do well on polished concrete if not cleaned up quickly.
Acidic-based fluids can etch the surface as well. That is why a pH-neutral cleaner should always be used if you need something stronger than just water to clean the surface.
Stain guards can be applied to polished concrete to help resist staining. These are sealers that penetrate the concrete and leave an ultra-thin coating at the surface. They will break down if exposed to solvents or other strong chemicals for very long. However, they will buy you time to clean up and they will protect the concrete from staining in many circumstances since they act as a sacrificial layer.
Stain guards will lose their luster if not maintained and may need to be reapplied or burnished with a floor buffer from time to time to keep the nice finish.
UPDATE!
There is a new clear coat sealer called BallistiX that can be applied directly to polished concrete. It will protect the surface from all of the factors just mentioned. You can read our review and testing here.
Lastly, polished concrete is expensive. Expect to pay $6 to $10 per square foot and up depending on the level of shine you want, the shape of your concrete, and the size of your garage floor. It can get more expensive if you want to stain the concrete as well. Pricing per square foot typically increases for smaller jobs due to the time and effort required for transporting and setting up the polishing equipment.
Conversely, there are situations where polished concrete can make for an excellent garage flooring option.
For example, if you live in a milder climate and don’t do much maintenance on your vehicles other than parking them in your garage, then polished concrete can do quite well as long as you keep the floor routinely clean.
If you do a search for polished concrete garage floors, the examples you will find are typically showroom-style garages with classic cars or nice garages that look cleaner and more orderly than the inside of most homes.
If you are the type of person who likes to maintain a clean garage and enjoys the routines of doing so, then polished concrete can give you years and years of service without issue.
Alternatives to Polished Concrete for a Garage
Yes, there are alternatives that can look very nice. Many of these do not require constant cleaning maintenance as well.
If you have hard-troweled or power-troweled concrete that is very smooth, there is an inexpensive option that can obtain a look that is somewhat similar to that of polished concrete. It involves the use of a stain guard that is burnished into the concrete surface with a high-speed buffer. The picture above is a good example.
You can learn more about stain guards and burnishing here.
Another alternative is to apply a high gloss clear coating to your bare concrete such as epoxy or polyurea. It will not produce the same raw look of exposed aggregate, but it will provide a very nice, glossy finish. If you grind the concrete instead of acid etching in preparation for such a clear coating, it will create a more consistent look in terms of coloring and texture.
A single-part polyurea is an excellent choice for bare concrete and it stands up extremely well in an automotive environment.
Then there are the MMA acrylic sealers like the floor above. MMA acrylic sealers are not as durable as their epoxy or polyurea counterparts, but they are less expensive and will do well if you use your garage mostly to park your cars and don’t use it for extensive projects and other busy work. MMA acrylics are easy to apply and all you need in most cases is clean concrete that has not been previously sealed.
As you can see, there are many things you need to consider before you decide to polish the concrete of your garage floor. While it can look absolutely stunning, it has its drawbacks if used in a garage environment.
We are aware that some concrete polishing companies and contractors may disagree with our assessments, but we feel it’s important to point out the realities of polished concrete for a garage floor in order for you to be more informed before making a decision. It’s an expensive investment and you need to feel confident with your choice.
If you are undecided about polishing your garage floor, we highly recommend contacting a few concrete polishing contractors to get a free estimate. Talk with them about your concerns and ask a lot of questions. They just may have the additional information that you require in your decision to have it done or not.
Regardless, a polished concrete garage floor can be a beautiful investment for your home. If you like the look, but the expense or realities of having such a floor are not feasible, then we recommend evaluating some of the other choices that we outlined above.
Ron Starr says
Can I use a two part epoxy coating sold as pool coating on my garage floor? The color is a pale blue, can I darken the tint?
Thank you!!
Shea says
Are you sure it’s an epoxy, Ron? Epoxy will yellow quickly if exposed to direct sunlight and is uncommon to use outdoors. Regardless, we wouldn’t recommend it. Epoxies are formulated differently for the environment and purpose for which they will be used. Pool epoxy is not going to have the same wear resistance and chemical resistance to automotive fluids since it is not designed to be driven on. You would be much better off purchasing the appropriate product.
Brian Forsythe says
I am looking for a durable, easy to maintain (ie sweep and occasionally spray out) concrete pad for a garage/shop in cold climate. Combination use of space for vehicle parking and maint, woodworking, and some hanging out for a pop or two;) Neat/clean finish but not show-off looking. Appreciate any recommendations for mix, troweling/finishing, and sealers etc.
Shea says
Hi Brian. Do you want the more natural concrete look or something more decorative with color?
Brian Forsythe says
Natural concrete look is good with me. Not looking for the floor to be a focal point, just easy enough to clean and not start spalling or need lots of upkeep.
Shea says
OK, that helps. The type of mix for the concrete varies by region so we can’t help you there. However, we do recommend a minimum 3000 PSI concrete pour / placement. 4000 PSI is preferred for workshops that may have lifts installed or garage / shop floors that will be busy with projects. The best finish for what you want to achieve would be a machine troweled finish. It helps to create the most level and smooth surface. However, a good steel troweled (done by hand) finish will work. One thing we can tell you from experience is that you don’t want to go the budget route when choosing a concrete contractor. There is nothing worse than ending up with a wavy floor with dusting issues because the contractor took short cuts and / or didn’t hire the best people.
The simplest sealer to use that will stand up well to winters and automotive chemicals would be a two step sealing process that involves GhostShield 8510. You can read about it here. This will leave the floor looking just as it did before and it will not change the grip level when wet. When done in conjunction with a machine troweled finish, you will end up with a surface that is very easy to sweep and keep clean. If you want anything more protective than that, it will require spending more dollars on a coating of some type. If you are interested, then the next step up that we would recommend would be TS210 by Concrete Sealers USA. You can read about it here. Feel free to follow up with any questions.
Isidro says
Are you recommend polished concrete at my garage I live in Denver Colorado
Shea says
Hello Isidro. No, we don’t recommend polished concrete for a garage if you live in Denver. Salt and deicing fluids will quickly dull the finish. We explain this in the article.
Pierre Barnard says
Hello
how about garages of high rises and shopping centres in Florida? They all seem to be polished. We live in a large condo and the garage floors have been left on the rough and look terrible.
Shea says
Hi Pierre. We are not familiar with the parking garages of Florida. Our guess is that they are machine troweled and not polished. Polishing is an expensive and time consuming process that would elevate the cost of a parking garage well beyond reasonable.
Joe says
Our home was insulated with spray foam during construction. Unfortunately the insulators were not very careful and got foam overspray all over my garage concrete floor. It traps dirt and grime, looks terrible, and is hard to sweep and clean. I was thinking the idea of polishing the concrete sounded good until I read your article. Do you know of another way of removing the foam overspray?
Shea says
Hi Joe. Polishing the concrete is an extreme and expensive solution for removing spray foam from concrete. I would recommend approaching the process in steps. First would be to use a floor maintainer with a stiff Malish brush attachment. This one here is what we would recommend. Many equipment rentals and Home Depot stores rent such equipment. Chemicals don’t really work on cured spray foam so water is all you need to run with it.
If that doesn’t remove it all, then a light grinding of the surface will definitely do it. We have an article about grinding here. A Diamabrush Removal tool would be the one to use. Afterwards, you will want to seal the concrete because the grinding will open the pores at the surface and allow fluids and dirt to penetrate easier.
JP says
We have done polished concrete floors in the garage for some of our (custom residential) builds. We generally stop at 400 grit. We’re intentionally going for a more matte finish.
These floors have worked well and while they aren’t as shinny as floors polished with higher grits, they still look great.
Shea says
Hi JP. Yes, a 400 grit hone and polish can look great. You may want to look into a product called Ballistix. It’s an inorganic silicon-ceramic coating that adheres extremely well to polished concrete and is not affected by petroleum, acid, and solvents. In addition, it will not stain from car tires. We are currently testing it and preparing an article. This product is absolutely incredible and the answer to polished concrete – particularly in a garage. You can get more info about it here.
JP says
Thanks. Our polished floors have been polished with a lithium densifier and then Prosoco Polish Guard. I have seen Ballistic advertised. Can it go on top of the Polish Guard?
Shea says
Yes, you can, providing the guard is one that is on their approved list. They say the only benefit to applying a guard beforehand is to slightly increase the coverage rate of Ballistix. Otherwise, it’s not necessary. We recommend contacting them to discuss. They also have a private Facebook group with many contractors who display their work, ask questions, and provide tips. Corey Colsen of Ballistix is very active there and frequently does live video to ask questions.
Carrie says
Great information… what would you recommend for a floor that has concrete paint on in (previous owner)? Can you grind it down and then use a stain guard? The space is used for parking cars in the Midwest. Thanks in advance?
Shea Walker says
Hi Carrie. You will need to grind the surface to remove the paint. We discuss how to grind your garage floor here. Grinding will make the surface to porous for a stain guard. You would need to hone the surface with finer grit diamond pads to make it smoother after the paint is removed. If you like the look of bare concrete, then we would suggest applying a clear epoxy or polyurea instead. It would protect the surface of the concrete much better against chemicals and winter weather. Another option would be TS210 by Concrete Sealers USA.