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  • Writer's pictureAndy Gordon

Surface Preparation: Acid-etch vs Grinding

Fail to prepare - prepare to fail.


For a floor coating to last a lifetime, a well-prepared concrete surface is imperative. The aim of surface preparation is to allow for strong bonds between the concrete’s surface and the base layer of epoxy, with the surface being free of chemicals, dust, and debris.


Two primary methods have emerged as viable options to prepare concrete for coatings; acid etching and grinding. Each method comes with pros and cons.

  • Acid-etching can be done without purchasing costly equipment but struggles to create a proper bond between the surface and coating IF the original concrete work was not done well.

  • Grinding requires the use of expensive equipment, but reduces high spots and is very effective in creating a surface that is conducive to a long-lasting coating.


How can we tell if the original concrete work was done well?

In the worst of cases, we find a top layer of concrete that flakes off. This “laitance” is a weak layer of concrete on the top surface, typically caused by overwet or overworked concrete. It prevents a bond from forming directly between a coating and the concrete substrate.

Concrete laitance example, bad for epoxy floor coatings
Example: concrete laitance

What does that mean for a floor coating?

It’s junk. If a layer of laitance is standing between the floor coating and a layer of strong concrete, the floor will delaminate and peel away over time. There’s nothing worse than putting time, money, and effort into a beautiful floor just to see it peel away over time.


Peeling epoxy floor due to bad surface preparation
Peeling epoxy floor

Improper surface preparation is the leading factor in failed floors. For long-lasting results, we find that grinding a concrete floor is the most effective method.



Layers of an epoxy floor
Layers of an epoxy floor

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