Grinding and Sealing Concrete Adds an Option to Contractors’ Offerings

grinding and sealing concrete in a kitchen gives long-lasting durability
The homeowners of this kitchen, part of a slab-on-grade home built in 2018, were concerned about the floor holding up to their five huskies and nearly as many small children. Contractor Jason Trihey alleviated their concerns by using 100- and 200-grit resin pads wet on a planetary polisher. He finished the grind-and-seal job with a coating of Impact Gloss with aluminum oxide for slip-resistance. Photo courtesy of Dapper Surfaces LLC

Capitalism is predicated on the idea that this isn’t a one-size-fits-all world. I might want a sportscar while you prefer an SUV. You play softball with the gang on Saturday afternoons while I like to hike nature trails.

The same holds true with concrete flooring. While it’d be nice if everyone wanted polished concrete floors, for several reasons that isn’t always on the table. Many times you need to come up with a durable, attractive alternative.

For many clients, that alternative may involve grinding and sealing concrete floors. For contractors, this method saves time, which translates into the client saving money.

“Everything is about price points,” says Troy Vancil of Boulder Polishing in Salina, Kansas. “It depends on what the customer wants to spend, but a grind-and-seal runs a little bit cheaper.”

Edgar Fragoso, owner of Surface Prep Systems in Stanton, California, has a slightly different take on it. He mainly deals with commercial work where tenants come and go or the building’s ownership changes. In these cases, a full polish isn’t only more expensive, it also takes much longer and can be a bother.

“A lot of people are in a space for a year or two,” he says. “And they’d rather do maintenance because they don’t want to go through the whole process again.”

Hold the wax

Where once his work divided about equally between residential and commercial, Jason Trihey of Dapper Surfaces LLC in Rochester, Minnesota, says he finds himself doing more residential work during the pandemic. Subsequently, the grind-and-seal method doesn’t only attract clients who have smaller budgets. It also attracts those more conscious about safety.

“Clients concerned with slip-resistance in some places, especially places that get wet frequently, can add aluminum oxide to the sealer. It gives a little more grip,” he says.

grinding and sealing concrete in homes like this happened a lot during the 2020 pandemic
During the pandemic, Dapper Surfaces found itself grinding and sealing more floors in people’s homes than in commercial settings. For this remodel, Jason Trihey and his crew ground the existing concrete floor. Then they overlaid it with Westcoat TC-4 fine texture cement and TC-0 micro cement. Photo courtesy of Dapper Surfaces LLC

The grinding-and-sealing method includes quick surface preparation to open the concrete and a durable product to seal it back up. The advent of water-based urethane seals has been a boon.

Trihey tells of one client with several U-Haul storage facilities. Originally, the specifications called for an acrylic sealer with several coats of floor wax.

“We upgraded them to the (St. Cloud, Minnesota-based) Ultra Durable Technologies Inc. Impact for concrete and terrazzo,” he says. “They were very happy with that. They don’t have to wax it anymore, and it has held up really well as far as durability.”

a concrete floor that has been given a unique treatment of color and polish followed by sealer
Next, using sea sponges and Preval sprayers, the Dapper crew layered diluted gray and black Ameripolish SureLock dye with colloidal silica added. After the floor dried, they cleaned it with a swing machine and water to remove some of the color before sealing it with Impact Gloss from Ultra Durable Technologies. Photo courtesy of Dapper Surfaces LLC
Appreciating the system’s simplicity

Vancil, who only recently added Ultra Durable to his list of suppliers, can’t yet speak of its durability. However, he made the switch because he has had issues with UV-cured urethanes.

“I just had problems getting those to work,” Vancil says. “The product seemed fine but getting it to cure in an aesthetic way became an issue. I was getting a lot of lines in it.”

polished concrete that has been sealed in a commercial bathroom contractor applying sealer to a polished concrete floor
Troy Vancil of Boulder Polishing in Salina, Kansas, and his crew recently used Ultra Durable Technologies’ Impact because Vancil was having issues with UV-cured urethanes. Photo courtesy of Boulder Polishing

Fragoso agrees that a water-based urethane sealer will do the trick. However, many clients who want multiyear durability choose to wax a floor after Surface Prep Systems has sealed it.

“It’s going to hold up, although a lot of clients throw two or three coats of wax on it. That way they keep their floor for three, four or five years,” he says. “As long as they keep up with the maintenance, they won’t lose a thing.”

Surface Prep Systems has used the Grind & Seal System from Westcoat Specialty Coating Systems for the past 15+ years. Above all, Fragoso appreciates the system’s simplicity.

“I got tired of other manufacturers changing formulas and changing systems every year,” Fragoso says. Not so with San Diego-based Westcoat. “It’s convenient and easy to use. I have about 40 installers working in the field and I don’t want to confuse them.”

Choose the right grinder

While a good grind-and-seal job relies heavily on a good sealer, contractors shouldn’t overlook the importance of proper floor prep. Prep work, however, will vary by job and contractor. Kurt Seppanen, a sales manager with Watertown, South Dakota-based grinder manufacturer Terrco Inc., says contractors should emphasize speed.

a high-sheen polished concrete slab that has been sealed to follow
Kurt Seppanen, a former contractor who’s now a sales manager with grinder manufacturer Terrco, says a typical grind-and-seal job entails using a 100- or 200-grit diamond. “Hit it in one direction, then hit it in the other direction, and then seal it up,” he says. Photos courtesy of Terrco

“Time is money,” notes Seppanen, also a former concrete contractor “Typically, you can do a 100 or 200 grit. Hit it in one direction, then hit it in the other direction, and then seal it up.”

Choosing the right grinder for a particular project depends a lot on the job size. While Terrco’s 701-S will suffice most residential projects, someone grinding and sealing concrete for industrial clients might need something as large as the 6200.

a Terrco 6200 on polished concrete
Terrco 6200

And, yes, grind-and-seal jobs have a place in industrial settings, Seppanen says.

Preparing the slab

“I did a lot of airplane hangars and helicopter hangars,” Seppanen says. “They were on a budget, so we’d do a quick clean-and-seal after construction. It lightens up stains and gives a protective finish.”

When grinding and sealing, he recommends having the proper equipment for optimal results. Besides a good grinder, contractors also need a water tank or a vacuum hookup. This depends on whether they prefer to work wet or dry.

To properly prepare the floor for sealer application, you must use the correct equipment and tooling. Fragoso says much of the decision on how to prepare a slab depends on the floor’s condition and hardness. For a slab that requires diamond grinding, he’d start a job with a couple of passes with metal diamond blades. He’d then switch to a transitional blade to remove grinding marks and present a smooth surface.

The secret ingredient

On the other hand, Trihey says, some jobs require little more than thoroughly cleaning the floor with a roto or swing machine. Others require various degrees of grinding. It all depends on the condition of the concrete.

“Sometimes, we’ll use sanding screens and water,” he says. “A lot of times when the concrete is in really good condition we’ll use a 100- or 200-grit DIP (diamond impregnated pad) wet under a roto to clean and smooth the floor. And then we’ll apply the water-based urethane. At times you can do as little as use a roto and stripping pad.”

The true secret ingredient to these contractors’ successes, however, comes from their suppliers and the technical support they provide.

“If I have a problem, all I have to do is pick up the phone. Someone from Westcoat will answer or get back to me right away,” says Fragoso. “And, if I need someone to come to a job site to evaluate the concrete or give me an idea on what I can do, they’re there. It’s amazing.”

“I was on a job on a Sunday night, and I had an issue,” says Trihey. “I got Travis [Negaard, president of Ultra Durable Technologies] on the phone and he helped me out. They always have answers to my questions.”

The bottom line, says Fragoso, is that the grinding and sealing concrete method is simple. “It’s just so easy, and it gives people what they want,” he says.

Moreover, Vancil adds, polished concrete isn’t always the best option for every job.

For people on tighter budgets, grinding and sealing concrete can fulfill the look they seek at a lower cost. “It’s another tool in my pocket for people who want the look of polished floors that’ll last a long time. It can solve people’s problems,” he concludes.

Products mentioned in this article

Offered by Concrete Decor Store

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