In the January 2017 issue of Concrete Surfaces I wrote “Three-Step Methods and Testing Procedures” describing what a three-step process for a polished floor is and how to use it. A year later, what successes have we seen from this new niche of accelerated polishing? What clarifications are necessary? What new areas have been explored?
To recap, what’s your initial reaction when you see “three-step polishing system”? Unfortunately, most of us read “polishing” as the complete process, not just the polishing steps of the overall process. So before you specify or commit your name and pricing to a three-step polishing system (defined as creating a salt-and-pepper finish using a clarity enhancer as a grinding aid), confirm if start-to-finish means a three-diamond-step process or a three-diamond-step process preceded by additional prep and grinding stages. Making a mistake here will negatively impact your costs, labor, and profitability.
What successes have we seen, and how do we judge success? The most basic ways are:
- From the customer and end-user’s standpoint, were the expected results delivered in a timely manner, at the expected cost, and did the floor continue to perform one or more years later?
- From the polisher’s standpoint, did the system allow crews to perform the work in the amount of time allocated and in the number of steps expected? Were the results what they and their customer expected? Were they profitable?
Let’s look at some projects from the past couple of years.
Cream Finish with Dye in Two Steps
We’ve talked about three steps, but how about only two steps to success? On this project, the specification called for a hard-steel-trowel finish of a laser-screed placement that was to receive dye, densification, and a polished cream finish. Creating flatness during placement is key to producing a cream finish with little to no exposure of fines and sands. And if that wasn't difficult enough for the polishing contractor, throw in a helpful finisher who heard about the black dye and decided to help by burning the floor during troweling. So now the contractor not only has the normal concerns when delivering a cream finish, he also has to cut through the burn to enable application of the dye and the densifier.
The first step was cleaning and conditioning the floor with a concrete-specific cleaner, then performing only one cutting stage using a clarity enhancer with 400-grit hybrid diamonds. Following an additional cleaning, the black dye and sodium silicate densifier were applied to the floor, with cleaning between steps. The final step was a dry polish with an 800-grit phenolic resin diamond. The phenolic resin residue was cleaned up with a high-speed burnisher and 800-grit burnishing pad. The floor was gorgeous and exceeded the customer’s and polisher’s expectations.
Skip forward nearly 20 months. The facility, a non-profit organization that serves late-teen/early-20s youth who live on the street, had no established cleaning program in place and had lost its shine. For nearly two years, cleaning consisted of a dry microfiber and periodic mop and bucket with water only. Now think back to the polishing specifications: cream finish, no exposed fines or sand. The starting grit was only 400. What this says is that the floor was never truly refined, never received a true grinding step, so the opportunity for wear was present from day one – if not protected with a successful densifier application to strengthen the near-surface wear area and protect the dyes.
Because this project was in our own backyard, I stopped in periodically to evaluate the floor and to reach out to the customer to ask if we could be of help. In this case, we were able to provide some proper cleaning materials that helped them achieve a true cleaning. You can imagine their, and our, joy when we were able to make the floor pop again simply by performing one thorough auto scrub with a proper cleaner followed by burnishing at 800-grit dry.
This is where you can see the proof in the three-step system. On this floor, which was never truly refined, which never saw a cleaner of any type (we’d rather water than the wrong cleaner), one clean-and-buff delivered outstanding results.
Large Aggregate Exposure In 5 Steps with No Grouting
This project was described in an article in the August 2017 issue of Concrete Construction titled “Planning to Polish a Concrete Slab”. The article addressed the interaction necessary between all parties involved in a concrete placement, especially when the finishing must take into account that the slab is to become the final, finished floor – polished and densified with large aggregate exposure, a staple of every Whole Foods store.
Steve Parker of Applied Flooring, the polishing contractor, described the process.
“We started cutting the floor a week to 10 days after placement. We used RetroPlate’s Kickstart to do the initial grinding wet. We used to do this kind of deep grind dry, but that resulted in lots of popouts that had to be grouted. Once we moved to a wet grind with the cutting fluid that didn’t happen. The result was greater clarity in the floor.”
The final floor exposing 1-inch and larger aggregate was achieved in five steps, not the three steps needed to achieve a salt-and-pepper finish. As noted by Parker, using the clarity enhancer (what amounts to the “three-step” system) provides a better finish, achieving greater clarity in fewer steps without the need and cost of grouting.
The System
Reduced-step, clarity-enhancing systems are being used successfully on floors of different ages, different end uses, and for different looks and exposures. The only time they’d be inappropriate is on projects where the use of water would cause problems.
Based on our experience, nearly 40% to 50% less water is required using the clarity enhancer versus a standard wet grind; and those who are trained in dry grinding are quickly buying into the decreased time and costs along with the increased profitability. The clarity, when steps aren’t skipped, provides a strong reflection on the polishing contractor’s abilities.
