Diamond Grinding as a Method of Surface Prep

In and of itself, concrete surface preparation seems fairly straight forward. Just make the existing surface ready to receive a new flooring system. Simple, right?

Well, it goes a little deeper than that. After many years and hundreds of thousands of square feet prepped and/or coated by myself or with other flooring installers, I can say there are few key questions that need to be asked before you choose your method of surface prep. I’ve narrowed it down to the top two:

1. What is coming up or getting ground off?
2. What is going back down?

When talking with installers about their prep needs, I often hear, “Why would it matter what is coming up anyway? Just grind it.”

Knowing these critical details will help with diamond selection and the method of removal, which in turn speeds up the process and requires less time and materials. Additionally, a thorough prep and grind is one of the best insurance policies for proper adhesion of the flooring system and ultimate job success. Flooring failures are likely to occur without this important first step.

For example, prep and removal of an epoxy coating for a new Granitex Chip System would differ greatly than a Cem-Dye System with a sealer (top coat) on a new hard power-troweled commercial slab with cure and seal.

When removing an existing failing epoxy system and prepping for a new Granitex System, a couple of things have to be considered. First, why did the existing coating fail? Was it moisture, poor material quality, lack of prep in the first case? Second, how thick is the existing epoxy? This is important because it gives you an opportunity to address the original reason for the failure. It also gives you an idea of where to start with your diamond tooling as far as which grit will be most effective at the removal, leaving a surface ready for the new material.

Most thin mil epoxies respond best with a 30-40 grit diamond in a medium-to-soft bond (the Phoenix area usually requires soft or extra soft bond). The following is based on the assumption that you are using a walk behind style grinder, whether it’s a counter rotating machine or a planetary. Using a good quality diamond tool with good point pressure will significantly help in removing the coating and leaving a profiled surface for the new floor system. Ultimately, grinding with diamonds leaves an ideal surface for material adhesion: a clean and maximum surface area.

Tip: If the diamond grit you are using has a lower profile than the thickness of the coating, it will take longer to remove and your diamonds will have a tendency to “gum up.”

ISI Diamond Tools USA is the manufacturer and seller of top quality German made diamond grinding, polishing and coating removal tools based in Phoenix AZ. Providing tools for any machine.