Epoxy floors fail for a handful of predictable reasons: poor preparation, moisture coming up through the slab, a system too thin for the traffic, or a topcoat that was never meant for sunlight or salt. A good contractor plans around all of them. A cheap one usually skips at least one. This guide explains what to look for so you can compare quotes properly.
Ask How the Concrete Will Be Prepared
Preparation is the single biggest factor in how long a coating lasts. Epoxy bonds mechanically to concrete, so the surface has to be opened up and clean.
Diamond grinding: The standard for professional work. It removes the weak top layer, contaminants and old coatings and leaves an even profile the coating can grip.
Acid etching: Common in DIY kits and quick jobs. It does not remove sealers, oil or old coatings and gives an inconsistent surface. Be cautious of any quote that relies on it.
Ask About Moisture
Concrete slabs, especially basements and slabs on grade, can push moisture vapour up through the floor. A coating applied over a damp slab can blister or lift. Ask whether the contractor tests for moisture and what they will do if readings are high.
Compare the Systems, Not Just the Price
A quote should say what goes down: primer, base coat, flake or colour, and topcoat, plus how many coats. "Epoxy garage floor" alone tells you nothing. Ask what the topcoat is: epoxy alone can amber in sunlight, while polyaspartic and polyurethane topcoats are UV-stable.
Ask About Repairs
Cracks, spalls and pitting should be repaired before coating, and the quote should say how. Ask whether moving cracks get a flexible filler and whether the contractor will tell you if a crack looks structural.
Get the Schedule in Writing
You should know how long the job takes, when you can walk on the floor, and when you can park on it or reopen the space. Those times depend on the system and temperature, so be wary of one-size-fits-all promises.
Red Flags
- No mention of grinding or repairs
- No moisture check on a basement or slab on grade
- A price far below everyone else with no explanation
- A vague scope with no system, coats or schedule
The Bottom Line
The best epoxy floor is the one installed over a properly prepared slab with a system matched to how you use the space. Ask the questions above and the right contractor will be easy to spot.