A Concrete Approach to Cleaning Concrete

“Really, you can get that clean?” my customer asked skeptically as I explained my ability to clean his garage floor. Yes,” I answered, “I think you’ll be amazed with what I can do.”

 I wouldn’t have been as confident 10 or 15 years ago. Allow me to explain:

One of my first commercial carpet cleaning jobs involved the carpeted (yes, carpeted) showroom of a car dealership. This poor carpet had been literally driven over, spilled on, dripped on, and generally abused for years. My brother Rob and I worked for over 8 hours with our little squirt-and-suck machines to get this mess looking good, and it wasn’t a big showroom. This was in the early 70’s, just as truckmounts were coming to market and we didn’t have one yet, so this job just about killed us.

As I look back at the good/bad old days of cleaning, it actually amazes and gratifies me to see how our success and proficiency at cleaning has progressed as our tools have improved. In fact, our tool selection now allows us to diversify in areas we never thought possible years ago. But I digress.



I ventured into the shop of this particular dealership and noted the heavily soiled and greasy concrete floor where they serviced vehicles. It never occurred to me to suggest to the management that I could clean that floor for them. Well, today I am going to encourage you to do just that: tell your customers that you can clean their concrete garage floors.

Before I jump into an explanation of the tools and procedures for cleaning concrete, I feel like I should suggest another diversification that will supply you with more business and simply makes a lot of sense: tile and grout cleaning. I imagine that most of you are already involved in this lucrative cleaning opportunity. I bring it up because if you are involved in tile and grout cleaning, you generally have all the tools necessary for basic concrete cleaning.

I say “basic” because today I am going to describe simple concrete cleaning as you would do in your customer’s garage. We will leave for another day the tools and accessories needed for more technical work, such as densifying and polishing concrete.

If you are in the business of tile and grout cleaning, you should have a rotary jet powered extraction tool, an edging tool, a grout brush, and various sprayers for applying solution. When taking on concrete, add to your tool box a stiff push broom and an all-plastic sprayer capable of handling acid-based products.

Now let’s examine some of the other components to this equation.

The Customer

Let’s not get ahead of ourselves without first talking about the customer and the sales process. If you are already set up in the house and cleaning carpet or even better, tile and grout, then it is a simple transformation to be ready to clean their garage floor.  Chances are the customer will be so pleased with what you have done with their carpet or tile, a simple suggestion to them that you can also apply the same expertise to clean their garage floor, will get you the job.

The Price

Generally, the customer will ask, “How much does that cost?” This is something for you to figure out. Practice cleaning your own garage, your neighbor’s or in-laws’. You will get an idea of what is required as far as time, chemicals and equipment. The garage (or other concrete surface) will generally be an add-on to the work you were originally hired to do, so you do not have the extra drive and set-up time.

 I would suggest at a minimum you want to be grossing $100 per hour during the cleaning, then add sealing to the equation to really boost your profit.

The Demo and Prequalification

A leading stone and tile trainer in the industry, Dane Gregory says that “whatever you tell your client before you begin the process is considered a professional opinion, whatever you tell them after you have not met their expectations is an excuse.” So this is important when it comes to most concrete cleaning: under-promise and over-perform. I suggest you do a small test area for your customer to make sure they are OK with the results.

You might say something like this in explaining your process: “Mrs. Jones, the nature of concrete is quite porous and with the different oils and fluids that drip from the car, they will actually penetrate beyond just the surface deeper into the core. Imagine the months and years this oil has to penetrate and you can see why it is a challenge to get it out. The good news is we can be very effective at getting the greases and oil from the surface but there will most likely be some lingering stains from those penetrating oils. Even with that I expect you will be happy with the results. Would you like me to clean a small section to give you feel for what to expect?”

Now with your customer’s approval and realistic expectations set, you are ready to clean. You should have a minimum of 800 PSI water pressure available, with 1,000–1,200 PSI preferable. You will use the rotary pressure tool to accomplish the majority of the cleaning but your preparation of the surface is important.

Generally, for oil-stained concrete, you will need a hard-hitting degreaser. I have experienced success on the heavy oil spots by misting a pure solvent citrus or pine booster on prior to applying the water-based solution. Some of the newer technology in water-based degreasers will include added peroxide to help lighten stains and brighten the concrete.

The solution can be sprayed on, mopped on or, my favorite, mixed in a bucket and then poured on. Use plenty of solution and have a stiff push broom available to spread it while giving some agitation to break the surface tensions of the old oxidized oil.

Important Note:  let the solution dwell for 10 or 15 minutes but do not let it dry. You’re hoping to get as much of the chemistry to penetrate beyond the surface as possible.

Begin to clean off the gunk using your rotary extraction tool. Use the brush attachment when working on concrete. If possible, have your customer inspect your process at the point where the floor is the dirtiest. When they can see the “before” right next to the “after,” their appreciation of your work will skyrocket.

One other cleaning step you may consider. Concrete is made from cement containing limestone (a source of calcium) and other aggregates and ingredients that are broken down by acids. There are acid-based cleaning products that are designed to clean, react, and remove a thin layer of the concrete, creating a brighter and cleaner looking surface. Some of these products are also peroxide-based, so they have the added effect of brightening the surface further.

You might consider using these products if the surface has more general soil than oil, or consider a follow-up to the initial alkaline-based cleaning with a mild acid/peroxide step to further brighten the concrete.  If using this product, it should be rinsed well following the proper amount of dwell time.

The final step is important for the customer and for your bottom line. Never leave the job without offering to seal the concrete. Generally a water-based penetrating sealer is preferred as the concrete does not have to be perfectly dry to apply it. A good penetrating sealer will not be visible when dry and will help to prevent future penetration of both oil- and water-based contaminants.

Industrial and decorative concrete is gaining popularity. Start with the basics and consider this lucrative add-on of garage floor cleaning for your residential customers.