Polishing a concrete patio is an easy way to turn a simple slab of concrete into an intentional design element. Polishing a concrete patio is also a good first step before adding stain to the concrete. The even surface of polished concrete will ensure that the stain absorbs more evenly, creating professional appearing results. Polishing and then sealing the concrete patio will also ensure that the concrete remains water resistant.
If you want to polish your concrete patio, plan on renting a concrete polishing machine. Many home improvement stores will rent one to you, but keep in mind that you will be responsible for purchasing the polishing pads and other materials required to use the polishing machine properly.
Step 1: Pressure wash the concrete patio, taking care to work from one end to the other to prevent soiling areas that are already clean. Remove any stains from the surface of the concrete patio with a scrub brush and dish soap and rewash those areas.
Step 2: Start polishing with a 40 grit diamond polishing pad on the concrete polishing machine. Start from one corner of the concrete patio, and work your way to the opposite end, making sure to lightly polish the entire surface of the concrete.
Step 3: Continue polishing, first using an 80 grit pad and then a 150 grit pad on the concrete surface of the patio. Sweep the surface of the patio, focusing on removing any dust from the polishing.
Step 4: Evaluate the surface of the concrete patio. If you like the texture and appearance of the patio, you can stop polishing and stain and seal the concrete. If you would prefer a smoother surface, however, you will have to complete a few additional steps.
TIP: Glossy, perfectly smooth concrete looks inviting in design magazines, but may not be appropriate for outdoor areas where slipping is of great concern. If you do decide to polish your concrete floor until perfectly smooth, plan on adding outdoor rugs to prevent falls when the concrete is wet.
Step 5: Apply a coat of concrete hardener with a spray bottle or pump sprayer. Try to achieve a perfectly even layer that has no dry areas or puddles. Let the concrete hardener dry completely before continuing.
Step 6: Continue polishing the concrete with the polishing machine. Start by using a 200 grit polishing pad, then continue with a 400 girt and 800 grit polishing pad until the patio has the desired texture.
Step 7: Apply a coat of concrete stain, if desired, using a paint roller. Follow the manufacturer’s instructions when applying the stain: some stains can be used just like paints, while others will require a special application process.
Step 8: Seal the surface of the concrete patio using a paint roller. Allow the sealant to dry at least 24 hours before walking on the patio. Plan on waiting an additional week before adding outdoor furniture or other items to the patio.