A polished concrete floor is the most affordable flooring option when considering true life-cycle costs. No wax or coating is needed to make this floor shine. It boasts an annual savings of as much as $1/square foot in maintenance costs over other floor finishes and coverings. However, this cost savings depends on making sure you’ve educated customers on implementing a thorough maintenance program.
Your customer’s maintenance program bears the brunt of continuously projecting the polished concrete floor in a good light. Even with basic cleaning, the shine can dull in high-traffic areas. Before the floor is even poured, ask your customer or architect:
- How is the space being used? The heavier the floor traffic, the more frequently cleaning will be required. Plus, a warehouse or industrial space requires a different maintenance program and frequency than a manufacturing operation, just as retail stores require different approaches depending on the retail sector. So ask—is it an office, a home, a restaurant, or a manufacturing plant?
- What level of shine am I looking to achieve? The greater the refinement and reflectivity desired, the greater the need for preventive maintenance.
- What is the exterior environment? Not only theirs, but their neighbor’s too.
The answers to those questions will help you advise your customer on a cleaning and maintenance schedule that, depending on floor use and traffic, includes daily dust mopping and daily or weekly wet mopping/auto scrubbing. Your customer will also need to schedule periodic burnishing as well as guard reapplication, if one was used.
What You Should Tell Customers
Don’t allow normal foot traffic to create a dull traffic lane. In polishing concrete, we often talk about refinement and grit levels. One way in which we all replicate the polishing process on a daily basis is simply by walking. In a normal situation in the interior of a building, where dry particulates are present, the average footstep is equivalent to a 400-grit finish. We normally equate this grit level to a matte-level finish. Now think about hard quartz sands. It’s not hard to visualize that these sands replicate the abrasives that are in our lower-grit diamonds—grits we equate with stock removal in the grinding process.
Protective mats can help prevent damage from foot traffic or the kind of foot shuffle that occurs in front of or behind service counters.
Extreme External Variables
A large retailer with polished concrete floors noticed extreme wear at the east entrance of the store, but not at the west entrance. Both entrances had blacktop parking lots outside the doors, the same type and coverage of walk-off mats, and the same maintenance schedule, but the east entrance was worn and had little shine left.
External factors were the cause of this conundrum. Not only was the eastern-facing door exposed to constant winds, but the retailer’s next-door neighbor on that side was a cement plant. The solution: Relocate the entrance from the east wall to the south wall, or increase the frequency of cleaning to combat the wearing and dulling effects.
Install a walk-off system at external doors. All external dry particulate that finds itself inside a building will act like sanding grit, and will dull the floor. The best preventive maintenance solution is to integrate walk-off systems at all entrances leading from outside or even from manufacturing or warehousing departments. A properly maintained walk-off system that flows 12 to 15 feet into a facility will eliminate 85% to 90% of potentially damaging dry particulate, along with solubilized oils and contaminants found in tracked-in water.
However, walk-off mat systems are not once-and-done solutions. They must be vacuumed and interchanged on a normal schedule; for just like a kitchen sink, they can only hold so much before they overflow. This overflow can carry the damaging particulate 12 to 15 feet further into the facility.
Use the proper cleaning products when wet mopping or auto scrubbing. A properly formulated cleaner for polished concrete is not pH neutral, but is closer to the pH of the polished concrete. For normal ASTM C150 Type II portland cement concrete, polished or not, the initial pH is around 12.5. After a 28-day cure, it is in the 11.5 to 11.8 range, so it is still a very alkaline product.
As time passes, the concrete at the surface interacts with carbon dioxide and may drop down closer to 10.4-10.6. This is an important distinction, because an effective cleaner needs to be alkaline. In addition to having an effective yet safe alkaline level, the specialty polished concrete cleaner must have agents capable of not only releasing soils from the surface, but also trapping soils and particulates into the solution to ensure that they “go out with the bath water.”
A proper cleaner continues to nourish and strengthen your floor. The final step in a good maintenance program is to re-introduce the densifying agent as a component of your cleaner*. This allows you to continually interact with and strengthen the new calcium hydroxide that is created within the slab in the presence of moisture — and the new calcium hydroxide created at the surface when moisture was introduced during the cleaning. Depending on the end use of the floor, you may recommend an additional protective guard** product to minimize potential staining or etching from spills.
*CreteClean Plus with Scar Guard™ – a revolutionary, proprietary blend of both a cleaner and a densifier specifically formulated for densified and densified-polished concrete.
**RetroGuard™ – a topical coating suitable for protecting concrete and natural or synthetic stone surfaces against oil and food staining.
**RetroPel™ – a stain repellent for concrete and terrazzo floors to protect against tough oil and water-based stains.
by Peter Wagner
Director of Supporting Products Development
This article was first published in Concrete Surfaces magazine in January 2016; minor editorial changes made August 2016 for publication in this newsletter.