Polished Concrete VS. Grind & Sealed Concrete? What's the Difference?

When you have a concrete floor, polished concrete is one of the most popular floor systems. Polished concrete floors are a type of flooring that has a smooth and shiny surface created by grinding, honing, and polishing. The process involves using different diamond abrasive grit sizes to achieve the desired level of gloss and smoothness. There could be as many as 8 grit steps before reaching the desired appearance.

Polished concrete is very abrasion-resistant, making it perfect for a very high-traffic area or in an industrial setting. The process can be time-consuming, labor-intensive, and in some cases costly. Although polished concrete can be used in many environments, there are times when a lower-cost system can be used while still meeting the intent of the owner.

This is where a Grind and Seal System comes into play. This system may appear to be polished concrete to the untrained eye, but it is far from it. When polishing, you completely refine the concrete surface with progressively finer diamond tooling. There are also chemicals used during the polishing process that will enhance the performance of the final floor. With a Grind and Seal concrete floor, you will use one or two metal bond diamond grinding steps, clean the floor, and then apply two coats of sealer. This is much less labor and time than a polished floor, ultimately reducing the final cost.

When to use Polished Concrete vs Grind and Sealed Concrete?

Grind and Seal projects are typically installed in light commercial, residential, and facilities that will be rented or leased.

The factors that will need to be looked at are:

• Time allowed for the installation
• What the facility is being used for
• Possibility of chemicals being spilled onto the finished floor
• Anticipated expectancy of final floor
• Budget

Compared to a polished floor system, a Grind and Seal process will reduce the installation time. It has fewer grinding steps and no honing or polishing steps. That could be as many as five fewer passes over the floor pushing a grinder - which correlates to time and cost.

Although Grind and Seal Systems use quality and durable sealers, the abrasion resistance of the finished sealed floor is not as high as a polished floor. A non-polished floor will never be more durable than a polished floor. We walk on and use non-polished concrete floors every day. The polishing process just makes them better in durability and appearance, but at a cost, of course. If the owner is willing to pay for a more durable polished floor, then polish it. But if their budget is on the lower side, Grind and Seal concrete could be the ticket. Setting expectations upfront is the key when presenting polished concrete vs. grind and sealed concrete.

Chemicals can do severe damage to many types of flooring. A polished floor has minimal chemical resistance. With Grind and Seal, you can select a sealer or coating to resist the chemical(s) your floor is expected to encounter. For example, DiamaPro® UV-HS Plus has great chemical resistance. Solvents, harsh hydraulic/cutting oils, and acids are on the long list of chemicals that do not affect UV-HS Plus. Now the installed cost will increase compared to a lower-performing sealer, but you will have a well-protected floor.

Overall cost normally correlates to longevity. The higher the cost, the longer the service life of the system (hopefully). Grind and Seal Systems are no different. By selecting a lower-cost sealer for a harsh environment, you will not see the service life you would of a higher-end material. A coating such as UV-HS Plus will last much longer than Diama-Grind and Seal in any environment, but they have different chemistries and when installed in the appropriate environment, each one will perform well.

Installation Comparison

When it comes to the installation process, the difference between polished concrete and Grind and Seal concrete is minimal. The initial and final steps are the same. With the initial steps, you are fully preparing the surface with a metal bond diamond tool. The fine or coarse aggregate will be uncovered and ready for the next step. The first diamond cut will take the most amount of time. You want to move slowly, making sure every inch of the surface is uniformly ground.

Every concrete surface is different. Some will have minimal to no imperfections and others might be covered with wood flooring, VCT, or tile that needs to be removed. The process to remove these will be the same with either system.

Not all floors are perfect, some will exhibit defects. Depending on the client’s desires, they might want these repaired. Those of us who have been in the surface preparation industry a while, know that most defects will be somewhat noticeable after being repaired. When you have enough experience repairing defects, you will develop a knowledge base of knowing how best to camouflage the repair.

No matter where you start with the Grind and Seal System, there is no reason to go any higher than a 70-grit metal bond tool. With a 70-grit tool, the surface will appear clean with an open pore structure and a very uniform, tight scratch pattern. A perfect surface to bond to.

With a Grind and Seal concrete floor, you can put the grinders away after the 70-grit metal. However, if you choose to go the polishing route, you will not be stopping at a 70-grit, you are only 30% completed with the floor grinder. You still need to make passes with a 50-grit hybrid, 100-grit hybrid, 200-grit resin, 400-grit resin, and 800-grit resin tool. Between the 200 and 400-grit resin, you will also be applying a densifier to harden the surface, increasing the durability.

Once the grinding is completed, the final sealer/guard application is performed. With Grind and Seal, you will be applying two coats of the sealer/coating of choice. With polished concrete, one or two coats of the guard you will be using are applied. The number of coats depends on which one you select.

Conclusion

Polished concrete is abrasion-resistant, easy to maintain, and attractive. Most concrete surfaces can be polished at a cost. That’s the key: cost. Many polished floors are overkill for the scenario they will be in. The client might be saying they want a polished floor, but when they hear the price, they become distraught. So, what’s the next option in your tool bag?

Grind and Seal provides the client with another option when selecting a floor system. Is the performance on the same level as polished concrete? No, it was never intended to be. Is the installation cost lower than polished? Yes, it is. It’s a system that provides the client with a floor that performs very well in many environments when the appropriate sealer is chosen.

If you need help deciding between polished concrete vs. grind and sealed concrete and figuring out the differences, you can always reach out to your closest Niagara Machine office to talk to our knowledgeable Customer Service staff or call your local Sales Rep for assistance!