Garage Floor Coatings: Why is prepping the concrete so important?

Pros in the garage floor coating business talk about “concrete prep” all the time, but what does that actually mean? In short, it’s the process of getting the surface ready so the coating bonds to the concrete floor securely. Without it, even the best products won’t last.

Whether it’s a residential garage or a large commercial floor, concrete preparation is the first and most important step in installing durable concrete coating systems.

Why We Use Propane Grinders

The go-to tool for professional concrete prep is the propane-powered grinder. These machines have the strength to grind concrete evenly and the speed to handle big spaces without dragging extension cords across the floor. They’re more efficient than other grinders, and they’re better at achieving an ideal CSP (more on that in a bit).

Propane grinders are also extremely safe. Propane has a narrow flammability range, and the machines produce near-zero emissions, meaning they can even be used indoors without concern. The end result is consistent, reliable prep work—the kind that makes a garage floor coating last.

Tools We Don’t Use

Not all prep methods hit the mark. Acid etching or water jetting may sound like quick solutions, but they leave the concrete too smooth, which means the coating can’t grip well. On the other end of the spectrum, heavy-duty options like sandblasting or rotomilling are unnecessarily rough for residential garages. Even electric grinders, while cheaper upfront, don’t offer the power or efficiency of propane units. They’re slower, less effective, and add more labor than value.

Grinding for the Right CSP

So what exactly are we grinding for? The answer is the Concrete Surface Profile (CSP). This is the scale that measures how smooth or rough a surface is, from CSP 1 (very smooth) to CSP 10 (very rough).

For garage floor coatings, the sweet spot is CSP 3–4. That’s rough enough for the coating to “hook into” the concrete, but not so rough that it compromises the finish. This Goldilocks zone is what ensures long-term adhesion.