Polishing Around the Customer's Clock

A polished concrete floor can be a great option for contractors to offer customers. But what do you do if the customer is a 24-hour grocery store? Plan properly and choose the right products. That's what NW Supply, Portland, Ore., did with a recent 40,000-square-foot polishing job.

To work around the store's 24-hour schedule, employees and customers, NW Supply held multiple meetings with the store personnel and its own employees, says Michael Henry, NW Supply's general manager for the specialty flooring division. In an initial meeting with store personnel, Henry split the floor into sections and planned out which section would be polished when.

Both the store and NW Supply designated a "lead person" for the job. These lead people met before each section was polished to move any necessary obstacles and then they met again after a section was finished to put it back in order, Henry says.

But resolving the challenge of working in an open, 24-hour grocery store that could not shut down for a period of days presented a bigger challenge. To achieve this, NW Supply used the Lythic Densifier - a colloidal silica - from Lythic Solutions.

On previous polished concrete Henry used sodium silicates. "Sodium silicates have to be scrubbed in with a machine and water, and it gets a little sloppy. Then you have to let it sit overnight, rehydrate and finally clean up the gel," he explains.

With the Lythic Densifier, which comes in a concentrated liquid form, all Henry needed to do was mix it with water and spray it onto the concrete and in an hour the floor was ready for polishing, he explains.

For the polishing, NW Supply used two HTC four-head diamond polishing machines. The first grinding pass used a 100-grit resin bonded diamond tooling. They then used a dust mop to spot clean the floor.

The second polishing pass used a 200-grit tooling followed by another spot cleanup. After the second pass, a crew member used a hand-pump sprayer to spray on the Lythic Densifier, Henry says. "You spray it out just like you spray fertilizer on your lawn and you spray until the floor reaches saturation." This polishing/cleaning pattern continued with a 400- and then an 800-grit tooling, Henry says. Finally, they added the Lythic Protector to the floor and then burnished it to finish.

Henry says the crew started work around 9:30 p.m. every night and did anywhere from 2,000 to 2,500 square feet per night. The entire floor was completed in just 21 days.

The Lythic Densifier was a big time saver for Henry. "It reduced our manpower, reduced a lot of the waste and cost about half as much," he says. "It reduced costs without reducing results."

Do you have a project you would like Concrete Contractor to consider for "On the Job"? E-mail your idea to Kim Johnston at Kimberly.Johnston@cygnusb2b.com.