Peeling in large sheets
Clean concrete underneath and a flexible sheet of coating means the bond never formed. Cause: inadequate profile, a contaminated slab, or coating over a curing compound or old sealer. Fix: full removal by grinding, then reinstall with proper prep.
Blisters and bubbles
Dome-shaped lifts, often with a damp underside, indicate moisture vapor drive or outgassing from air in the slab pores. Fix: moisture test, then reinstall with a mitigating primer. Small outgassing bubbles from coating a warming slab are a timing error: always coat on a falling or stable slab temperature.
Fisheyes and craters
Small round voids where the coating pulled away from the surface mean contamination: oil, silicone, or wax that was not removed. Degreasing before grinding, not after, is the correct sequence, because grinding drives surface oil deeper into the slab.
Soft or tacky areas that never harden
This is a mix-ratio or mix-time error, or coating below the minimum temperature. Uncured resin cannot be rescued; it must be scraped and ground out and that section reinstalled.
Wear-through at tire paths and door lines
Not a defect: an under-specified system. Thin film, no topcoat, or a soft resin in a high-abrasion location. This is the failure that recoating actually fixes: scuff sand and apply a fresh polyaspartic clear.
Cracks reappearing through the coating
The slab is moving. A rigid coating over an active crack always telegraphs. Fix: rout and fill with a flexible polyurea, and consider a more elastic base coat. Control joints should generally be honored, not coated over rigidly.
The verdict
Sheet peeling and blistering mean start over. Wear-through and gloss loss mean recoat. Diagnose before you pay for either.
Frequently asked questions
- Why is my garage floor coating peeling in sheets?
- Large-sheet peeling means the bond never formed. The usual causes are inadequate surface profile, contamination, or coating over a curing compound or old sealer.
- What causes blisters in a floor coating?
- Blisters are usually moisture vapor drive or outgassing from air in the slab pores. A moisture test and a mitigating primer are the fix.
- What are fisheyes in a coating?
- Small round voids caused by surface contamination such as oil, silicone, or wax. Degrease before grinding, because grinding drives oil deeper into the slab.
- Can a peeling floor be recoated?
- If the failure is localized wear, yes. If it is sheet peeling or widespread blistering, the coating must be fully removed and the system reinstalled.
- Why do cracks reappear through the coating?
- The slab is still moving. Rigid coatings telegraph active cracks. The fix is a flexible polyurea fill and possibly a more elastic base coat.