How to Polish a Rough Concrete Floor

A rough concrete floor may look intimidating and unsightly, but with a little effort, it can be polished and smoothed to a lustrous sheen. Concrete floors are increasingly popular for businesses and residences that are going for a modern rustic industrial look. With a concrete polisher and the correct grade of smoothing and polishing attachments, you can get your rough and raw concrete floor looking smooth and shiny.

Open area in front of the building
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A rough concrete floor may look intimidating and unsightly, but with a little effort, it can be polished and smoothed to a lustrous sheen.

Preparing to Polish Rough Concrete Floor

Before beginning to polish the concrete floor, you will need to test the floor's hardness to ascertain what polishing disks will be most appropriate. With a MOHS Concrete Hardness Tester, you can scratch the floor with a series of metal bond diamond abrasives that will help you determine exactly how hard your floor is.

Once you know how hard the floor is, you will need to fill in any holes or cracks in the floor so that you have a smooth and even surface to polish. Local hardware stores will sell an epoxy that can be applied to any cracks or holes. It doesn't matter if some of the epoxies leaks out of the holes and creates bumps because you will be polishing the surface anyway.

Concrete Grinding Before Polishing

Once the epoxy has hardened and dried, you can move on to the next step. Using a grinder, like a werkmaster concrete floor grinder, grind down with 16-, 30/40-, 70/80-grit bonding to get the floor to the flattest surface. Begin with the highest number of grit, and move to the lower numbers as necessary. The next step is to remove any metal tooling marks with 50-, 100- or 200-grit transitional tooling.

This will remove any surface scratches on the concrete floor and prepare it for the polishing step. Any tooling marks on the floor should be completely removed after grinding with the transitional tooling. If they are not, go over the floor again. Next, vacuum your floor thoroughly, taking care to get over in the corners and in the spaces where the wall meets the floor, as dirt, dust and grit particles can become trapped easily.

Then, apply a hardening densifier to the surface to increase density and protect against water penetration, which can cause damage and staining. Apply with caution and restraint. Do not saturate the floor with densifying liquid. This can leave stains that are difficult to remove.

Concrete Grinding and Polishing

To finish up your DIY polished concrete floor, you will get to the polishing portion of the operation. If you don't decide to purchase a floor polisher, you can easily rent a floor polisher from a local home improvement store or an equipment rental company. The werkmaster concrete floor grinder is a popular piece of equipment to use, but there are other floor polishers on the market.

Once you have all of the necessary equipment, you should begin polishing the floors with resin bond tooling in an increasingly fine level of grit. Begin with the coarsest grit, somewhere around 200. Then, progress up to 400. Be sure to vacuum the floor thoroughly between each polishing pass. After 400, you can go up to 800. Then, move to 1500. Finally, you can use a 3000-grit pad to buff the surface of the floor.

Treating Your DIY Polished Concrete Floor

Once you've completed the polishing process, you should see a smooth, shiny surface. After completing the polishing, make an effort to protect the floor from staining and water damage by applying a sealant coat.

A commercial stain guard followed by a coat of sealant will protect the surface from damage caused by chemicals, spills, foot traffic, scratches, heat and sun exposure.


Ashley Friedman

Ashley Friedman

Ashley Friedman is a freelance writer with experience working in the home, design and interiors space.