▽ +09.00Problem · Floors
The epoxy floor is peeling
The epoxy lifts from the concrete in flakes or patches, or blisters appear and break under traffic.
What you see
- Flakes or patches lifting, often with a clean underside
- Blisters, sometimes with liquid inside
- Peeling along joints, cracks or wheel paths
- Soft or sticky areas
- Whitening or dark damp patches under the coating
Possible causes
Poor preparation
Laitance, dust or a closed surface: the coating bonds to a weak skin.
Moisture and vapour pressure
Slabs on grade without a vapour barrier push moisture up.
Contamination
Oil, grease or curing compounds left on the slab.
Mixing and application errors
A wrong ratio, poor mixing or application outside the temperature limits.
Traffic beyond the system
Thin coats under forklifts or hot tyres.
How it is diagnosed
The diagnosis confirms the cause before any repair is chosen.
Look at the back of a flake
A clean back means adhesion failure; concrete attached means a weak substrate.
Test the moisture
In-situ RH probes (ASTM F2170) or the plastic-sheet test (ASTM D4263).
Pull-off tests
On the sound areas, to decide between local repair and replacement (ASTM D7234).
Review the system against the use
Thickness and type against the traffic and chemicals.
Possible solutions
The fix follows the diagnosis; these are the common options and their systems.
Local repair
Cut back to sound coating, grind, prime and re-coat.
Systems
Full replacement with proper preparation
Removal, then shot-blasting or grinding, and a moisture-tolerant primer where needed.
Systems
A heavier system for the traffic
Self-levelling or broadcast systems, and car-park systems on decks.
What not to do
- Recoating over loose or peeling coating
- Acid etching instead of mechanical preparation
- Ignoring slab moisture
- Opening to traffic before cure
General educational content; final values and requirements follow the manufacturer’s TDS and the approved project specification.
Common questions
Can a peeling floor be fixed without removing everything?
If adhesion tests show the rest is sound, local repairs work; widespread failure needs full removal.
How is slab moisture checked before epoxy?
With the plastic-sheet test to ASTM D4263 as a first check, and in-situ relative humidity probes to ASTM F2170, comparing the result with the system data sheet’s limits.
Technical inspection
Need a diagnosis for your case?
Send photos, a description and the location; our engineers identify the cause and the fix after an inspection.