Symptoms
- Chunks or flakes of the epoxy coating lifting off the floor
- Bubbles or blisters under the coating before it peels
- Peeling concentrated in certain areas (like under a car or near a door)
- Bare concrete visible where coating has come off
Likely causes
- CommonMoisture vapor coming up through the slabConcrete without a proper vapor barrier can push moisture up that breaks the epoxy bond from below.
- CommonInadequate surface preparation before applying the epoxyEpoxy needs a properly profiled (etched or ground) surface to bond; skipping this step is a leading cause of failure.
- PossibleApplying epoxy over a sealed or previously coated surface without proper prepCoating over an existing sealer often prevents proper adhesion.
- PossibleHot tires or heavy point loads lifting a weakly bonded coatingHot tire pickup, where tire heat softens and lifts epoxy, is common with poorly bonded or lower-quality DIY kits.
What to do
- Identify the extent of the peeling; small isolated areas may allow patch repair, while widespread peeling usually means a full recoat.
- Use a scraper or grinder to remove all loose and peeling coating down to bare, sound concrete.
- Check for moisture issues by taping plastic sheeting to a bare concrete area overnight and checking for condensation underneath.
- Address any moisture source (grading, drainage, a vapor barrier product) before recoating, or the new coating will likely fail the same way.
- Properly prepare the surface this time, typically by grinding or acid etching to create the right texture for the epoxy to grip.
- Apply a new epoxy or polyaspartic coating system, following the product's specific surface prep and moisture testing recommendations closely.
- Consider a professional installer for this project, since proper diagnosis and surface prep are the main reasons DIY epoxy jobs fail.
Tools and parts
- Floor scraper
- Grinder (with dust shroud)
- Plastic sheeting (for moisture test)
Epoxy garage floor coating kitSearch: “epoxy garage floor coating kit”
When to call a pro
Call a professional epoxy flooring installer if moisture testing shows a problem or if you want a longer-lasting, warrantied result.
Safety
Use caution
Wear a respirator rated for concrete dust when grinding, and ventilate the garage well when applying epoxy or etching products.