When epoxy fails, what the photos actually show
Since I started this site in early 2026, I've gotten probably 40 emails with photos attached. "My floor is doing this, what does it mean?" I started saving them in a folder. Here are the patterns I keep seeing, with what each failure actually is and what it costs to fix.
Important framing. Most epoxy failures trace back to bad prep or wrong product selection, not defective materials. Rust-Oleum EpoxyShield is not a bad product. Penntek is not a bad product. But either one rolled onto a contaminated slab is going to fail.
Failure mode 1: Peeling in sheets
What the photo shows. Large sections, sometimes 12 by 12 inches or bigger, of coating lifting cleanly off the concrete. Often the underside of the peeled piece looks smooth and clean, with no concrete dust attached.
What it means. Adhesion failure. The coating never bonded to the concrete. Root cause is almost always one of three things: inadequate mechanical profile (etched when should have ground, or lightly ground), residual contamination (oil, curing compound, or dust not fully removed), or coating applied over a moist slab.
Fix. Grind the entire floor back to concrete. Repeat prep correctly. Recoat. On a 500 sqft garage that's $1,500 to $3,000 in additional cost on top of whatever you already spent. Contractor warranty should cover this if you're in warranty. If DIY, you eat it.
Prevention. Read prep is everything. Most adhesion failures are prep failures.
Failure mode 2: Bubbling
What the photo shows. Small to medium raised bubbles in the coating, some blistered and broken, some still intact. Often appears in patches, not uniformly across the floor. More common in basements and slab-on-grade garages.
What it means. Moisture vapor transmission. Water is moving up through the concrete and the coating is trapping it. Once enough vapor accumulates under the coating, the pressure pushes the epoxy up into bubbles.
Fix. Depends on severity. Small isolated bubbles can sometimes be patched if you grind them out and apply a moisture mitigation primer in the patch. Extensive bubbling means grind-and-redo with moisture mitigation across the whole slab. Budget the same $1,500 to $3,000 as adhesion failure, plus $750 to $1,500 for the moisture mitigation coat.
Prevention. Calcium chloride test or Tramex CME4 moisture meter before coating. If the slab is over spec, use Ardex MC Rapid or similar moisture mitigation primer. Full protocol at basement epoxy moisture.
Failure mode 3: Hot tire pickup
What the photo shows. Coating lifting specifically at the tire contact zones, in parking-spot-shaped patterns. Usually first appears after a hot day when the car has been parked for several hours. The coating sticks to the tire and peels up when you pull out.
What it means. The topcoat is too soft and plasticizers from the tire rubber are migrating into the coating. Standard DIY epoxy with no urethane topcoat is especially prone.
Fix. Affected areas can be ground down and patched with a hot-tire-rated topcoat (urethane or polyaspartic). Full floor re-topcoating with polyaspartic costs $1.25 to $2/sqft over the existing base.
Prevention. Use a topcoat rated for hot tire pickup. Polyaspartic topcoat over epoxy base is the gold standard. Let the floor fully cure 7 days before parking a hot vehicle. Detail at hot tire pickup explained.
Failure mode 4: Fish-eyeing
What the photo shows. Small circular divots in the finished coating, roughly the size of a pencil eraser, distributed across the floor. The coating looks dimpled, like orange-peel texture but with actual holes.
What it means. Surface contamination that was present during application. Usually oil, silicone (WD-40 is a major culprit), or wax on the concrete surface repelled the coating locally.
Fix. If isolated, fish-eyes can be sanded and spot-coated. If extensive, re-topcoat the entire floor.
Prevention. Degrease, degrease, degrease. If you've ever sprayed WD-40 or silicone spray on the slab, you need a dedicated silicone remover (GP 120 or similar) plus a grind to get it out.
Failure mode 5: Flake wear-through
What the photo shows. In a flake coating, specific areas (usually where the car tires sit, or where the trash can gets dragged out) where the topcoat has worn through and the flake is exposed. Sometimes individual flakes lift out entirely.
What it means. Not really a failure. Just normal wear in high-traffic zones. The topcoat has finite abrasion resistance and eventually it wears down.
Fix. Topcoat refresh. Every 5 to 8 years, a flake floor benefits from a fresh clear topcoat roll-over. Budget $1 to $1.50/sqft. Extends the life of the base coat and flake indefinitely.
Prevention. You can't really prevent wear, but you can slow it by using a thicker topcoat at install and by being gentle with dragged items.
Failure mode 6: Yellowing
What the photo shows. The coating has a yellow or amber tint that wasn't there at install. Most visible in white or light-gray floors. Worst in areas that get direct sunlight.
What it means. UV degradation of aromatic epoxy. Normal for standard epoxy in UV exposure.
Fix. The yellowing itself is cosmetic and doesn't affect performance. If you hate the look, a polyaspartic or polyurethane topcoat refresh will mask the yellow and prevent further shift. $1.25 to $2/sqft.
Prevention. UV-stable topcoat at install, or go with polyaspartic. See polyaspartic vs epoxy.
Failure mode 7: Crack telegraphing
What the photo shows. A hairline crack visible in the finished coating, tracing a line that matches an underlying concrete crack. Sometimes the coating has split along the crack, sometimes it's just visible through the topcoat.
What it means. The concrete moved or the underlying crack wasn't properly filled before coating. Epoxy is not a structural repair, and slab movement telegraphs through.
Fix. Rout out the crack through the coating, polyurea fill, spot-patch the coating. Or, if extensive, full refinish. Detail at cracked slab epoxy fix.
Prevention. Fill cracks properly before coating. Use a flexible polyurea filler, not just mortar. If the slab has active settlement cracks, address the structural issue before epoxy.
Ninety percent of failure photos I get show a prep problem, not a product problem. The remaining ten percent are moisture or UV, which are predictable and preventable with the right topcoat.
When to DIY-fix vs re-hire
Small isolated issues (a single hot-tire patch, a few fish eyes, one cracked area) are DIY-friendly. Grind the affected area, patch with compatible product, feather the edges, topcoat over.
Extensive failure (more than 10 percent of the floor area) is a grind-and-redo. That requires the same equipment as the original install and is not a good weekend project. Hire it out. Budget full new-install pricing.
The warranty question
If the failure is within warranty, call the installer first. A reputable contractor will inspect and repair under warranty. Most flake systems carry 5 years, most polyaspartic systems 10 to 15.
If the contractor is out of business or denies the claim, you're stuck. This is why you hire reputable contractors with a local track record, not the $1,999 special that pops up on Facebook.
Planning a fresh floor?
Start with the calculator for honest cost expectations. Read prep is everything, the 7-step prep protocol, and DIY vs pro. The best way to avoid a failure photo on your own floor is to not skip the prep.