Polished Concrete - October 2009

By Brian Hamilton

More designers and facilities managers are beginning to experiment with decorative concrete, and, in particular, polished concrete, the least expensive kind of decorative concrete. While grocery stores and other kinds of retail establishments have been using it for years, often in conjunction with resilient flooring or some other accent flooring, it’s showing up more frequently in schools and business settings such as The Gap corporate offices.

Initially used in warehouses, it started to become fashionable in high tech offices on the West Coast and has slowly spread east. It was developed in 1996 when Advanced Floor Products of Springville, Utah, combined European stone polishing technology with its own chemical expertise. The company’s system, known as Retro Plate, has been used on well over 100 million square feet of flooring.

While polished concrete’s an extremely durable and easy to maintain kind of flooring, it isn’t necessarily easy to make the final product look as it was envisioned, either by the owner or specifier. Translating that vision can take a lot of work, and it usually requires some flexibility on the part of the customer. It’s not like installing hardwood or tile, where the owner knows exactly what the final product will look like. For example, there are various levels of gloss and several ways concrete can be colored.

“We’re doing a lot of schools now,” says contractor Jim Cuviello, owner of Cuviello Concrete Polished Stained Crafted of Stevensville, Maryland. He’s also director of the Concrete Polishing and Processing Technical Institute.

“We’ve also done a lot of retail, but that is down now, and we’re doing a lot of office. Two years ago, we didn’t see schools or offices specifying polished concrete but now we’re seeing large applications being specified. There are two main reasons the industry is growing. One is the LEED benefit, and the second is because of the lower cost of maintenance.

“This industry is just in its infancy, and it’s a little like the Wild West. In the next year or 18 months, I think you’re going to see it explode. Eventually I think the carpet guys and VCT guys are going to feel threathened, but it’s going to be a while before polished concrete takes significant marketshare.”

His comment about the Wild West refers to the general state of the industry. There are no formal industry standards, and there are a lot of mom-and-pop businesses with varying degrees of technical skill competing for work. Cuviello describes his firm, with up to ten employees, as medium to large compared to other firms that only do polished concrete. He says most of the best contractors have a background working with marble or granite. In addition, he says, there’s a significant lack of understanding by customers about what polished concrete is and entails. He also notes that while the polishing equipment is improving, it’s still not much better than it was 12 years ago.

Polished concrete helps earn credits in LEED projects because concrete materials come from local sources. Concrete is also produced locally, and it can be made more sustainable by substituting fly ash in the ingredient mix in place of some of the cement. In addition, concrete can help with points for indoor air quality, can help cut lighting costs, can store heat, and can last a long time. Concrete itself can also be recycled at the end of its life.

Although stains can be a problem if spills aren’t handled promptly, day to day maintenance requires little more than damp mopping, whether by hand or machine.

Craig Walton, owner of Diamond Concrete Polishing in Boise, Idaho says that most of his recent jobs have called for ripping out old vinyl tile and grinding the concrete under it to give it a polish. He says that while the initial cost is higher, his customers like the lower maintenance benefit associated with concrete.

By far, contractors say, retrofits are the most difficult kind of polished floor to do because the quality of the finished job is heavily dependent on the condition and quality of the concrete underneath.

“You have to manage the customer’s expectations,” Walton says, adding that these kinds of jobs often require a lot of hand holding. “We have no control over the concrete. If they want a perfect floor, they need to go to an epoxy (overlay). If they want polished concrete, they need to be able to live with some character in the floor.”

Cuviello agrees that retrofits are more problematic.

“What we get in a lot of specs is they just say ‘polished concrete’ with nothing about how to achieve the end product. That’s one of the things that we’re trying to help corral.”

Designer Sandy Carpenter, a senior associate and specialist in school design at Becker Morgan Group Inc., has specified polished concrete for the new $70 million James M. Bennett High School in Wicomico County, Maryland. She says it may be the first project of its kind in the state. The district decided it couldn’t afford terrazzo at about $20 per square foot and thought decorative concrete sounded like a good option. Initially it wanted stained concrete, but went with polished concrete after seeing a stained floor that had faded, giving it an uneven appearance. She says that although she had met with a number of stained concrete product representatives, none of them mentioned the fading issue. So she changed course, knowing that she didn’t want to keep using vinyl and she certainly didn’t want to install a floor that would fade and be noticed by the public that authorized funds for the project.

“We had been using VCT and then tried EVT but we were finding that the surfaces were too soft,” Carpenter says. “We had problems in dining rooms and furniture created indentations. We tried something different with each project.”

The polished concrete will also allow a more customized floor. For instance, Carpenter, working with the facilities manager, has chosen to mix red and white glass with a charcoal colored concrete to give the cafeteria a hint of school colors.

Carpenter says, however, that this part of the project has been far more labor intensive than simply specifying vinyl.

“This has taken multiple mock-ups to get what we wanted,” Carpenter says. “It takes a lot of face time with the contractor.”

Even though she seems to be sold on polished concrete, she would hesitate to recommend it until she gets a better feel for the overall cost. She’s also a little concerned about how it will be received by the school’s maintenance department.

“Our biggest fear is they are going to try to polish it with wax like VCT,” Carpenter says.

Designer Martin Dusbiber of GMB Architects and Engineers in Salisbury, Maryland also believes that polished concrete is a good option for schools, but admits it can be a harder sell because the initial cost is so much higher than traditional VCT, which checks in at about $1.50 per foot. He’s using polished concrete in a new 75,000 square foot elementary school, of which about 65% will be polished concrete.

“We recommended it to the owner but it took a while to sell them on it,” Dusbiber says, as his estimated cost for polished concrete comes to $6.50 to $8.50 per foot.

“We were tired of VCT and the maintenance of it, and clients can’t afford terrazzo or tile, so we began looking for alternatives.” The payback in maintenance should be fast.

However, concrete’s hardness can cause acoustical problems in many situations, so, in the case of a classroom, it’s likely that sound-deadening ceiling tiles and wall finishes will be necessary. In addition, it can cause fatigue for people like teachers who stand on it for long periods of time.

Polished concrete can also make a difference in the warmth of a building because it conducts heat well. It tends to make occupants feel cooler at any temperature, which can be an advantage in the South during the warm months, and a disadvantage in the north during the cold months. However, it can be installed over underfloor heating systems.

Dusbiber notes that the construction process has to be tightly managed in order to end up with a quality floor. It’s especially important to get the right, consistent concrete mix. To end up with a consistent color, the concrete needs to be colored at the plant, but that doubles the cost of the concrete. And the darker the color, the more expensive it is.

“You have to stockpile all the materials for the colorized and polished concrete and every batch of concrete has to come out of the same stockpile to get the same coloration and consistency,” Dusbiber says. There have to be constant inspections at the batch plant and the construction site.

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