Riding trowel polishing has come a long way and can now achieve the same finish as polishing grinders.
Marcus Juarez Riding trowel polishing has come a long way and can now achieve the same finish as polishing grinders.

Polished concrete projects have gotten progressively bigger over the past few years, but polishing 500,000 square feet of an older floor in poor condition is a big job, and completing the whole thing in 90 days takes the right contractor and the right equipment. That’s where Syncon, Livonia, Mich., came in. “This project was a task, and a daunting one at that,” says Syncon president Ryan Klacking. “Although this may have been a project that others may not have tackled, Syncon was ready for the challenge. Not only were we able to finish within the allotted time, we delivered outstanding results.”

The Romulus Business Center in Romulus, Mich., had been a distribution center for multiple tenants. When Syncon arrived, the floor had 80 mils of old epoxy coating, partition walls, deteriorated joints and cracks, and thousands of embedded bolts. Klacking explained, “We were able to survey the floor and took three to four weeks to plan which left us about 60 days to complete the job. We got the job because no one else could meet the deadline.”

Marcus Juarez

The condition of the floor was so bad that early discussion contemplated ripping it out and replacing it but that couldn’t be completed within the required time frame so Syncon proceeded with a complete rehabilitation. The owner’s expectation was to have the building end up “like new.” This included the flooring, all MEP upgrades, new paint and walls, ceilings, pipes, and the demolition and replacement of the fire suppression system as well as the breakdown of the current wall system that had previously separated four different tenant spaces.

Syncon started with removal of the epoxy coating using PCDs on the HTC 2500 ix, the largest grinder currently on the market. “We own the only two of these machines in North America,” says Klacking. “It has three grinding heads that grind 94.5 inches wide. This machine replaces six 30-inch machines.”

Marcus Juarez

At the same time workers began on the joints and cracks. “There was 58,780 lineal feet of construction and control joints from ¼ to ½ inch wide that needed to have the old joint filler removed and replaced,” says Klacking. “Some were degraded and 7,640 feet needed to have 4 inches of shoulder cut out and rebuilt. There was also 36,750 feet of cracks that needed to be routed and filled, 350 steel bollards that were removed and repaired, and 8,490 bolts that we cut off with a torch and patched over.”

For the polishing sequence, Syncon followed this plan:

  • Started with the HTC 2500 and PCDs to remove the epoxy
  • Used riding power trowels for the remainder of the project starting with a grind using 25-grit metal and 40-grit metal tools dry
  • Ground with 70-grit and 120-grit metal tools wet
  • Switched to 100-grit and 220-grit hybrid tools wet
  • Moved to 400-grit and 800-grit resin tools wet
  • Installed the surface densifier/hardener (Retroplate)
  • Finished with 1500-grit and 3000-grit tools dry to get the very high shine the customer was looking for
  • Installed RetroPel stain repellent
  • All joints and cracks were cleaned and routed where necessary and the old joint filler removed and replaced full depth with an epoxy joint filler or polyurea
  • Joints that needed to be rebuilt were cut out to create a shoulder 4 inches wide and then rebuilt using Metger-McGuire Armor Hard Extreme; the joints weren’t unstable—there was no deflection across the joint
Syncon president Ryan Klacking admiring the success of this huge project.
Marcus Juarez Syncon president Ryan Klacking admiring the success of this huge project.

“We had 15 workers on site and actually finished the project in 75 working days although we were allowed 90 days,” says Klacking. He feels that polishing with trowels is opening new doors for polished concrete on larger projects where it would be too expensive to polish using standard planetary polishing equipment. This may be true, “especially on floors where they can go with less refinement, you might call it concrete enhancement.” That wasn’t the case on the Romulus project, where a highly refined and durable 3000-grit finish was achieved in record time.

This project was awarded first place in the Industrial category in the 2018 Polished Concrete Awards.