Should I hire a pro or use a DIY epoxy kit?

If your garage floor already has paint or another coating, you might be wondering if you can simply apply new epoxy over it. It’s a reasonable question—removing old coatings sounds like extra work and cost. However, coating over weak or incompatible layers is one of the fastest ways to guarantee failure.

Why Coating Over Old Paint Usually Fails

Epoxy is only as strong as what it’s bonded to. If you apply new epoxy over old paint, the epoxy itself might cure perfectly. But if that paint is peeling or poorly adhered, your new floor will fail when the paint lets go. Essentially, you’re chaining your investment to the weakest link.

Old garage floor paint—especially in St. Louis garages that experience temperature swings and road salt—is often compromised even if it looks fine. Here’s why:

• Hot tires lift it in spots.

• Moisture gets under the edges.

• Freeze-thaw cycles break down adhesion over time.

Coating over these issues means inheriting all the problems that come with them.

There’s also the issue of compatibility. Some coatings don’t bond well to each other, or they create a chemical reaction that prevents proper curing. Without knowing what’s already on the slab, you’re gambling.

How Professionals Handle Existing Coatings

A reliable epoxy contractor will test adhesion and often recommend removing old coatings entirely. This process typically involves diamond grinding the slab down to clean concrete. This eliminates the unknowns and gives the new epoxy the mechanical bond it needs for long-lasting performance.

• Rare Cases: If the existing coating is a high-quality epoxy that’s still fully bonded and in good condition, it might be possible to scuff it and recoat. However, this is uncommon in residential garages and still requires testing and proper surface prep.

Skipping the coating removal process almost always backfires. The new epoxy will fail prematurely, and then you’ll end up paying to grind off two layers of coating instead of just one.

How Seal Epoxy Evaluates Older St. Louis Garages

Seal Epoxy frequently works in established St. Louis neighborhoods where garages have decades of history and multiple layers of unknown coatings. The team doesn’t guess—they:

• Test adhesion

• Inspect for underlying issues

• Almost always recommend grinding back to bare concrete

This approach may seem like overkill, but it ensures the new floor lasts 10-15 years instead of peeling off within 18 months. Seal Epoxy uses commercial grinding equipment to remove old coatings efficiently, and they treat it as a standard part of surface prep, not an expensive add-on.

Homeowners Appreciate the Honesty

It’s better to hear upfront that the old coating needs to come off than to deal with a failed floor later. Seal Epoxy’s free in-home assessments include a thorough inspection of what’s on the slab, followed by a clear recommendation on how to prep it correctly.