How to Polish Concrete Floors

Concrete floors are a great choice for any room in your house. What once seemed like only an option for commercial buildings, concrete floors have begun to catch on in residential buildings.

Often, carpet or other flooring materials are removed to expose the concrete underneath, giving you the perfect flooring material that you may not have even known you had!

With the concrete floor exposed and knowing how to polish them, you can have the perfect polished concrete floors in your house.

How to Polish Concrete Floors

Not all concrete floors are the same. Depending on the damage, you may have to address several cracks that need to be filled in the concrete using polyurethane joint filler or a spalling compound. Small cracks or holes can be filled with polyurethane joint filler, while spalling concrete—which can be large holes—will need to be filled with a spalling compound.
You should always perform a mockup on a small portion of the concrete flooring to ensure the section will turn out the way you want and you know what to expect.

1. Remove All Materials and Adhesive from the Concrete Floors.

If you are pulling up carpet or other types of flooring, you will need to make sure you get all the flooring materials and adhesive removed from the concrete. This includes any glue, tack strips, or sealant used on the original flooring.

You should be able to pull up the carpet or flooring by hand. Any stubborn glue or adhesive flooring materials will need to be removed using a concrete grinder. At this stage, you should only use the concrete grinder to remove stubborn glue and adhesive to expose the concrete and determine if repairs need to be made.

2. Inspect the Concrete for Cracks and Joints

Once you have removed all the flooring material and adhesive from the concrete, you can determine if repairs need to be made. You may have cracks and joints that need to be filled with concrete filler.

Repair all cracks and joints at this point before continuing. If you are filling small cracks or holes, the polyurethane filler should drive relatively quickly—however, if you have to repair a large section of spalling concrete, it may take as longer.

3. Grind the Concrete

Using your concrete grinder, you will need to grind all of the concrete floors. This is similar to using a power sander to sand hardwood floors for restaining. Grinding concrete floors will remove the surface of the concrete. This creates a smooth surface that will be prepared for polishing.

On the concrete grinder, you will need to attach diamond tooling. This is what will spin to remove the surface of the concrete. Like sandpaper, diamond tooling requires an abrasive pad to remove the surface of the concrete.

We recommend starting with an abrasive 40-grit diamond pad for your first pass on the concrete floors. The next pass should be made with an 80-grit diamond pass, and the final pass should be made with a 150-grit diamond pad—or finer.

4. Harden the Concrete

The hardening process is called densifying. Your concrete floors will need to be densified using a concrete densifier. A concrete densifier is a hardener that will add reinforcement to your concrete. You can apply the concrete densifier to your concrete floors using a sprayer or a pad.

Removing the surface of the concrete can weaken the integrity of the concrete floors, so adding a concrete densifier to harden the concrete and reinforce it is crucial. It will take at least one hour for the concrete densifier to dry.

5. Polish the Concrete

Once the concrete densifier has been applied and dried, you will polish the concrete floors using your concrete grinder with a diamond pad between 100-grit and 200-grit. After making your first pass with the concrete grinder, you will replace the diamond pad with a very fine diamond pad between 800-grit and 1,500 grit.

6. Seal the Concrete

Now that you have polished the entire surface of your concrete floors, it’s time to seal it! Any concrete guard will work for this. The concrete sealant will not only protect your concrete floors from becoming damaged, but it will also help keep them easier to maintain!

Conclusion

Polishing concrete floors is an easy project that you can do if you have the right tools and know what steps to follow. As we mentioned in the beginning, we recommend performing a mockup on your concrete floors to ensure they turn out the way you want them to.