When most people think about epoxy floors or industrial coatings, they picture the glossy, durable, and seamless surface you see at the end of the job. What few realize, however, is that the beauty and longevity of that surface rely on one crucial, often unseen element: surface preparation.

At Polzin Epoxy Designs, we like to say that the coating is only as good as the surface it bonds to. That’s why we don’t just focus on what you see—we focus on what’s underneath. If floor prep isn’t done correctly, even the most advanced coating systems will fail prematurely.

In this blog post, we’re diving into the most common and effective floor prep methods used before applying coatings like epoxy, polyurea, polyaspartic, and urethane. We’ll explore grinding, shot blasting, acid etching, and more. If you’re a homeowner, business owner, or contractor considering floor coatings, this guide will give you the knowledge you need to make smart, long-term decisions.

Why Is Surface Preparation So Important?

Surface preparation isn’t just an optional step—it’s the foundation of the entire flooring system. Coatings rely on mechanical and sometimes chemical bonds to adhere to the substrate. If the surface is smooth, oily, dusty, or damp, the coating won’t stick properly. Over time, this leads to issues like:

• Peeling or delamination

• Bubbling or blisters

• Cracks and chips

• Uneven texture or appearance

Proper prep ensures the coating bonds tightly, creates a uniform profile for adhesion, removes weak or damaged concrete, and opens the surface to allow penetration and grip. Simply put, a well-prepped floor will perform better, look better, and last significantly longer.

Method 1: Concrete Grinding – The Gold Standard

Concrete grinding is one of the most widely used and effective floor preparation methods in the industry, especially for residential garages, commercial shops, and interior concrete spaces. It involves using specialized machines with rotating diamond-embedded discs to mechanically profile the surface.

At Polzin Epoxy Designs, we grind every concrete floor to achieve a minimum CSP (Concrete Surface Profile) of 3 to 4, which is ideal for epoxy and polyaspartic coatings. Grinding opens the pores of the concrete, removes surface contaminants, and exposes the aggregate for a strong mechanical bond.

Benefits of Grinding:

• Creates a consistent and predictable surface texture

• Removes sealers, paints, glue, or coatings

• Opens up pores for moisture testing and vapor barrier evaluation

• Offers control over profile depth and finish quality

Challenges: Grinding requires skilled technicians, proper equipment, and dust control systems—All of which we have here at Polzin Epoxy Designs.

That said, grinding is the preferred method for interior and exterior projects, where precision, cleanliness, and a smooth, professional result are critical.

Method 2: Shot Blasting – Heavy-Duty Prep for Industrial Performance

Shot blasting is another professional surface prep method used commonly in warehouses, manufacturing plants, large garages, and industrial flooring projects. This technique uses a machine to shoot small steel beads (“shot”) at the concrete surface at high velocity. The impact removes weak concrete and creates a rough, aggressive texture—perfect for heavy-duty coating systems.

Shot blasting is especially useful when dealing with large surfaces that need to be coated with high-build or elastomeric systems. It’s also ideal for preparing floors that are exposed to forklifts, chemical spills, or heavy machinery, as the aggressive profile allows for maximum adhesion.

Where We Use It:

• Industrial buildings with high traffic

• Outdoor concrete like parking decks

• Projects requiring a CSP 4 or higher

• Floors with old, failing coatings or sealers

Things to Know: When used strategically, in the right spaces, shot blasting is one of the most effective tools for creating a durable bond between the floor and the coating.

Method 3: Acid Etching – The Old-School Approach (and Why We Don’t Use It)

Acid etching is a chemical method that uses a solution—usually muriatic acid diluted with water—to open up the concrete surface. The acid reacts with calcium hydroxide in the concrete, slightly roughening the surface and exposing pores.

While it was once a common practice among DIYers and early coating contractors, acid etching has largely fallen out of favor in the professional world. It may still be used in certain limited scenarios, but it has several significant drawbacks:

• It doesn’t remove oils, paints, or coatings effectively

• The surface profile is inconsistent

• It can trap moisture in the slab

• Environmental and safety concerns with chemical runoff

Why We Don’t Recommend It: Epoxy coating manufacturers today recommend mechanical preparation like grinding or shot blasting for a reason: it creates a stronger and more reliable profile. Acid etching might create a temporary bond, but it doesn’t offer the long-term strength and adhesion we’re after.

At Polzin Epoxy Designs, we prioritize surface integrity, and chemical etching just doesn’t meet our standards for high-performance installations.

Moisture Testing: An Often-Overlooked Prep Step

One of the most critical and often overlooked parts of surface prep is moisture testing. Concrete is a porous material, and moisture vapor can move up through the slab over time. If this moisture reaches the surface underneath a non-breathable coating, it can cause bubbling, blisters, and coating failure.

Before installing a coating system, we always perform moisture testing. If the readings are too high, we apply a moisture vapor barrier (MVB) to block the moisture and protect the coating. This step is especially important in basements, older garages, and areas with high water tables.

Skipping this step to save time can jeopardize the entire installation. It’s one of those things that may not be visible on day one, but it’s critical to long-term performance.

Cracks, Spalling, and Imperfections: Repair Comes First

• Hairline cracks

• Wide structural cracks

• Spalling (flaking or chipping concrete)

• Pitting or soft spots

Depending on the issue, we use specialty patching compounds, polyurea crack fillers, or epoxy repair mortars to create a stable surface. Cracks are repaired before coating, not after. This gives the floor a clean, seamless look and ensures that the coating system lasts.

Once the repairs are done, we often go back over the surface again with grinders to blend and flatten the patched areas into the surrounding floor.

Prep is More Than a Step—It’s a Philosophy

At Polzin Epoxy Designs, we treat floor preparation not as a step in the process but as a philosophy of quality. No matter how advanced or beautiful a coating system is, it won’t succeed without the proper foundation. That’s why we invest in state-of-the-art grinding and vacuum equipment, ongoing technician training, and strict prep protocols for every project—big or small.

We’ve seen countless jobs where another installer rushed prep, skipped repairs, or failed to test for moisture—and within months or a year, the coatings started peeling, bubbling, or delaminating. Our clients come to us for long-term value, not short-term fixes, and we deliver by making surface preparation the cornerstone of every project.

What Prep Looks Like on Your Project

If you choose to work with Polzin Epoxy Designs, you’ll notice our attention to prep right away. We start with a site visit, during which we’ll inspect the concrete, test for moisture, and walk you through our plan. When our team arrives on install day, we don’t jump right into coating—we grind, patch, clean, and prepare.

You’ll see grinders connected to dust collection systems, technicians inspecting every crack and edge, and a methodical process that may take longer than some competitors—but it’s all part of delivering a floor that performs for years to come.

Final Thoughts: The Foundation of a Better Floor

Whether it’s a residential garage, a showroom floor, a commercial space, or an industrial warehouse, the key to a successful coating system is not just the materials you use—it’s how you prepare the surface.

Grinding offers control and consistency, shot blasting gives an aggressive bond for industrial strength, and moisture barriers protect your investment. Together, these methods form the backbone of high-performance coatings.

At Polzin Epoxy Designs, we take pride in doing things the right way, not the fastest. When you invest in your floor, you deserve a team that invests in preparation.

Because before you see the beauty on top, we’ve already built the strength underneath.