You have decided to use an epoxy coating on your concrete floor. The next order of business is to decide what floor preparation method should be used. There are several different methods to prepping for a floor coating. Preparation of your floor is the most important step! In this article we will explain the different methods and the pros and cons of each.
Floor Prep Before Applying Epoxy
The first step before applying any epoxy coating is to prep the floor. It is imperative that you clean your floor thoroughly. When working on a concrete base you should look to fill in any cracks, hairline fractures, joints, and divots that may be exposed. Epoxies as a general rule will not 'fix' a floor so any issues such as small holes, cracks, and dings in the floor should be filled in or repaired first. Even 100% solids high build coatings will 'telegraph' surface irregularities if not repaired first. We recommend that the floor be prepped first, and then repairs made, and then coated. Oil spots will need to be removed and the floor will need to be degreased. The reason for this is that repair materials will adhere better to a prepped floor. ArmorPoxy sells a full line of crack repair and patching products for all of your prep work needs. Once these areas have been repaired you can proceed. Be sure to catch any areas you might overlook while preparing your floor.
Methods
There are three main floor prepping methods, so choose the one that will best suit your needs.
1. Acid Etching
The first is acid etching. This technique is the most D.I.Y. option, as other techniques require machinery and can be tricky to use if not accustomed to this type of work. Acid etching works well when there has been a new concrete pour and there are no pre existing coatings to remove. If pre-existing coatings exist then it is recommended to mechanically prep the floor as acid etching will not work on a coated surface; etching only works on bare concrete.
First you need to remove any grease or oil stains. Use a commercially available degreaser and follow the directions accordingly. If you are unable to remove the oil stains, it's best to use our Oil Stop Primer which can adhere to concrete with residual petroleum products embedded. Apply the diluted acid solution to your floor. Once it is spread out evenly use a scrubber, a stiff bristle broom, or a similar tool to work the acid solution. Once that it’s done, let the acid sit for up to 10 minutes, this will allow the process to take effect. The acid puts millions of microscopic textures into the floor to promote adhesion. Next you have to remove the spent acid. This can be done through power washing and vacuuming once the floor has dried. Make sure to remove the residue before the acid dries. If you find that your floor is in very bad condition with oil and grease, you may want to consider mechanical preparation using diamond grinding (see below).
2. Diamond Grinding
The second method for preparing your floor is diamond grinding. This method will restore smoothness to your floor and remove surface contaminants, which is needed prior to an epoxy coating. The diamond grinding method requires the use of machinery, however, it is quite easy to do. You will need a floor grinder with the proper attachments for your floor. Once the machine is turned on, use a side-by-side swaying motion to smooth out the entire surface of your floor. After this is complete, vacuum heavily to clear away any residue left behind. Be sure to always keep the grinder in motion to avoid grinding circular rings and low spots into the floor. You will want to achieve a concrete surface profile (CSP) of at least a 2. Please note that if you mechanically prep your floor it is mandatory to use the proper matching primer since grinding makes the floor very porous and if you don't prime, you could end up with an uneven finish. For more info on CSP please see our article on What Does a CSP mean?
3. Shot Blasting
The final method that can be used to prepare your floor is shot blasting. There are various styles for this technique but all require machinery to flatten out a surface. Some people prefer diamond grinding to this method, but both will get the job done. The machine will pelt tiny metallic beads into the floor to blast away any stains or damages to the base. The advantage of this, as opposed to diamond grinding and acid etching, is that there will most likely not be any residue left over, as the machine captures everything. This technique requires some skill and should be used on larger scale jobs. Please note though that shot blasting can leave 'lawnmower lines' in the floor which may telegraph through the finish so shot blasting is not recommended for garage floors, and is most often used on larger commercial projects. Floor preparation is the most important aspect to achieving a smooth and even outcome. Be sure to research your method of choice before and as always the ArmorPoxy team is here to answer any questions you have! After all of this is complete, you will be ready to apply your epoxy flooring!
Conclusion
Proper floor preparation is key to a successful epoxy coating application. Each method—acid etching, diamond grinding, and shot blasting—comes with its own advantages, making it essential to choose the one that best fits your floor's current condition and your project's scope. Acid etching offers a simple DIY option for bare concrete, while diamond grinding provides precision and a smooth finish, ideal for most home and commercial applications. Shot blasting is effective for large industrial spaces but may leave visible lines that could affect the final look.
By taking the time to thoroughly clean, repair, and prep your floor, you’re setting the foundation for an epoxy coating that adheres well and provides a long-lasting, high-quality finish. Once your floor is prepped, you can confidently move forward with applying your epoxy coating. Remember, if you need guidance, ArmorPoxy’s expert team is ready to assist at every step for a flawless result!