The Benefits and Challenges of Concrete Polishing
By Painters USA Team
— Published January 18, 2024
Concrete vs. Polished Concrete
It’s rare to walk through any modern commercial or industrial building and find bare concrete floors. As versatile and durable as it is, concrete also has several less desirable traits, including these five well-known ones:
- Porous as a sponge, ready to absorb and be stained and corroded by any liquids that land on them.
- Vulnerable to temperature swings can cause thermal expansion and contraction that can lead to cracking.
- Susceptible to wear patterns and uneven surfaces due to activity like heavy and consistent forklift traffic.
- Prone to cracking and spalling (breaking off in fragments) over time and under the pressure of operational use.
- Drab and dark, which makes space less pleasant and safe while affecting everything from worker productivity to customer comfort in commercial facilities.
So, facility owners and property managers allocate significant time and resources to determine the best way to finish and protect their concrete flooring substrates.
For most types of commercial or industrial facilities, three main options are available:
- Covering like carpet or vinyl.
- Coating systems like epoxy.
- Concrete polishing.
Let’s start with the ins and outs of polished concrete.
Concrete polishing in a nutshell
Concrete polishing combines mechanical and chemical steps, applied in a systematic process that takes considerable skill and years of experience to master. The mechanical aspects include grinding and honing with specialized equipment and abrasives while chemicals like hardeners or densifiers account for the chemical components. Optimal refinement at each stage is necessary for high-quality, durable results and requires mastery of three mechanical and chemical components:
- Operation of specialized grinding machines and polishing tools
- Selection and application of abrasive materials in a variety of coarse to fine grit levels
- Selection and application of chemical additives that densify and seal the concrete
When properly installed, a polished concrete floor is both durable and economical, with reduced expenses for care and maintenance.
It bears repeating: proper installation is key.
Anyone can say they can polish concrete floors and rent the equipment, but it doesn’t take long for incompetence and inexperience to cause problems. Unfortunately, many problems are not discovered or don’t occur until well after the project is completed. We’ll explore how to cover all of your bases throughout this series.
Benefits of Polished Concrete
Each of polished concrete’s numerous benefits will be explored more closely, but here’s a list of some basics.
Polished concrete can provide a high level of surface strength to handle the wear and vibration of heavy traffic and equipment loads. Often, this foundation comes from the concrete itself, but polishing improves density.
While a highly polished surface may look wet, it is not slippery, making it an excellent option to minimize slips, trips, and falls. Under normally dry conditions, polished concrete floors meet OSHA and other industry standards for coefficient of friction guidelines - we’ll explore this more in-depth later in the series.
Performance, Durability, and Useful Life
This is where concrete polishing shines. Grinding, honing, and polishing the concrete removes imperfections, restores the surface, and makes the concrete more resilient. Chemical densifiers harden and seal the concrete to strengthen it further. Life cycle maintenance costs are low, and the useful working life is long.
Ease of Maintenance
The ease and low cost of routine cleaning and maintenance are a key buying point for polished concrete. Polished concrete resists staining and makes the surface impervious to the abrasive nature of most cleaning products and processes. Cleaning and maintenance tips will be provided in future blogs!
Protection of that Vital Concrete Slab
For hardworking industrial facilities - where flooring performance may be the only thing that matters - concrete polishing will protect the surface from the rigors of operational wear and tear. The densification and hardening of the concrete provide a strong, durable finish to maximize the useful lifespan and reduce maintenance-related downtime.
Polished concrete is bright and reflective, which not only makes any space look better but has been shown to reduce energy and lighting costs. For design considerations, polished concrete offers an endless array of options. It can be colored with dyes, scored or engraved, embedded with decorative aggregates, or embellished with logos or other graphics. We’ll take a closer look at design elements later in the series.
Support for LEED and Other Green Initiatives
Polished concrete floors can help organizations achieve credit toward LEED certification. They reflect light to help minimize and reduce energy use, last many years for greater sustainability and less replacement, and require very little raw material consumption.
Challenges of Polished Concrete
While polished concrete delivers many benefits and high value, it also presents difficulties and shortcomings. Contractors who are unaware of these possible “gotchas” or unable to deal with them are unlikely to meet job specifications or client expectations.
Facility Conditions and Operational Requirements
Polished concrete performs wonderfully in many commercial and industrial facilities. Yet, for some circumstances, polishing may not be the best solution:
1. Facilities where chemicals are produced or used regularly
Chemicals will stain and etch into a polished concrete surface over time. Even polished concrete is susceptible to acid and caustic chemicals. Strong chemical resistance is best achieved through specialized performance coatings rather than polishing, but that’s a topic for a future blog series!
2. Floors that need to meet stringent sanitary or hygiene standards
Facilities like food and beverage processing plants or pharmaceutical facilities operate under unique requirements for their floors and other surfaces. To comply with health department standards and FDA/USDA/SQF requirements, a seamless coating to prohibit bacterial growth and withstand rigorous cleaning chemicals is usually a better fit. Again, we’ll be exploring this in the future.
3. Concrete in poor condition
Concrete slabs that are not flat and level or have severe cracking and spalling problems are challenging when achieving quality results. A trustworthy, qualified concrete polishing contractor will advise when a concrete substrate needs more extensive repairs or alternative solutions. You’ll learn about the criteria in this series.
4. Areas better served by coverings
Some facilities or areas are better suited to coverings like tile or carpet rather than polishing or coatings. Coverings offer warmth, quiet, and softness that may be better for certain buildings and space allocations.
Variables that Need to be Considered
There are two types of variables to consider. Those that a concrete polishing contractor can control and those they can’t. They need to mitigate both in the right proportions at the right time for a successful outcome:
1. Within contractor control
Contractors control the selection and use of equipment, abrasive material, chemical densifiers, and sealers.
Regarding equipment, speed, motion, and pressure all affect the grinding and polishing steps. Too much or too little of any will impact everything from surface preparation to sheen specifications. The same applies to the abrasive materials and selecting the right type and grit (fineness/coarseness) at each process stage. There’s very much an art to proper polishing!
Finally, as concrete densifiers have become a de facto standard, choosing the right chemicals and correctly applying them to manufacturer specifications will affect the performance and lifespan of the polished surface.
2. Beyond contractor control and requiring accommodation
When it comes to circumstances we cannot control, the current overall condition of the facility and, more specifically, the concrete floor go at the top of the list. The flatness and levelness of the floor, along with the quantity and severity of imperfections, are something we must consider and accommodate. The mix design of the concrete can also be a factor in the equation.
Architectural features like corridors, other tight spaces, columns, and other fixed obstacles can add complexity and take more time to navigate.
These are some of the innate features that may be beyond the contractor’s control, but they must be considered and incorporated into estimates, bids, and project timelines.
Good Flooring Contractors Overcome All Obstacles
The contractor’s job is to address and solve these and any other challenges; that’s why you hire professionals. You rely on them to deliver the outcome you want and need while the process goes as smoothly as possible… because the downtime clock is always ticking.
You should prioritize and carefully assess the experience, skill, and reliability of the concrete polishing contractor. Will they be able to live up to the promise of their bid or proposal? Do they cover job specifications to show their understanding and mastery of the process?
We’ll take a deep dive into contractor selection later in this series. But next week, you’ll learn more about if and why polished concrete is a good fit for your facility and the different types of polished concrete.
Do you have a project idea already in mind? Or, want to learn more after the article? Contact one of our experts or request an estimate now!