When you want to restore the look of polished concrete, you may be considering one of two options. First is a topical treatment to smooth and shine the concrete slab, which is quick, convenient, and has a low cost. The second option is to mechanically polish the concrete by grinding the slab, adding grout, and using a progressively finer polishing pad to bring out the shine. While a topical polish may be easier, shortcuts have consequences. A mechanical polish lasts much longer, maintains its beauty and resistance to abrasion for longer, and over time, requires less cost to maintain.
As part of our “how-to” series, we’re walking you through how to grind, grout, and dye concrete to get beautiful, long-lasting results. To see our process in action: check out the video below!
Grinding Your Concrete Slab
First, the whole process starts with grinding the concrete to remove any existing coatings, even out any inconsistencies, and establish a scratch pattern. To do this, we used 30 grit diamonds and made two passes with our concrete grinder. After this, we used a 70 grit diamond pad to begin honing the slab.
While your concrete grinder should have an attached dust collector to eliminate much of the dust and debris, before you grout the slab, you’ll want to run a vacuum or mop over the slab to eliminate any dust or debris.
Grouting Your Concrete Slab
With a clean, smooth slab, it’s time to add grout. This step is necessary to fill in any cracks, voids, or pits so the slab will be stronger, smoother, and have a more attractive shine. We use a 100 percent solids epoxy to apply a skim coat to the slab followed by adding a liberal coating of marble powder. Marble powder is specifically formulated for terrazzo and concrete flooring and ensures a high-quality finish.
We can’t stress enough how important it is to not use sand or even concrete dust from the grinding process as these contain impurities and aren’t suitable for long-term usage.
After the marble powder is applied to the wet epoxy, we grind the slab to remove excess marble and extend the life of our tooling. Then, we use beveled grout pans to press the marble and epoxy into any pits and voids while pressing the air out to ensure proper filling and sealing of these flaws in the surface.
After drying for around 18 hours, it’s time to move on to the polishing step.
Polishing Your Concrete Slab
Once the epoxy and marble coating is dry after about 18 hours, we recommend beginning the grinding process again with a 70 grit pad followed by a 100 grit copper pad to eliminate any excess and begin the refining process.
At this point, we highly recommend using a concrete densifier to make the slab denser and improve the impact and abrasion resistance of the slab. This will improve longevity and minimize damage over time.
Then, we follow the following pattern of polishing:
- 200 grit copper for wet grinding to remove the scratch pattern and act as the “bridge” to dry polishing;
- 400 grit dry polish;
- 800 grit dry polish;
- 1800 grit dry polish;
By this point you should see a lovely sheen to the slab, and at this point you can apply your concrete dye. Dye is purely aesthetic and allows you to get creative with the look of your concrete slab. You can do one simple color or create patterns – it’s purely the preference of you or your client.
After applying the water-based dye, we use a 3500 grit resin pad to remove any swirl patterns left by the tooling and add additional clarity and shine to the floor. After this step, you’re ready to apply any urethane or sealant to the floor and congratulate yourself on a job done right.
Contact Us for Concrete Polishing Equipment and Tools
In order to get the best results on your polished concrete, it’s important to have the proper equipment and supplies. At BMD, we specialize in helping you get the tools you need for the job at hand to help you get excellent results while improving efficiency. To learn more or to get a quote for supplies, contact us at (815) 324-8071 or by filling out our contact form to get started!