Epoxy Floor Problems: A Troubleshooting Guide
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Latux Epoxy supplies flooring contractors in South Florida and installs floors of its own. That second part matters on a page like this, because almost every coating failure we get asked about is one our crews have already stood on, scraped up and re-coated. This guide sorts the common failures by what you can actually see, tells you what each one usually means, and is honest about which ones come up with a grinder instead of a roller.
General guidance, not a diagnosis of your floor · Authorized dealer for every brand we carry · Counter in Pompano Beach · We speak English, Spanish and Portuguese
Find your symptom
What is the floor doing?
Pick the one that looks like yours. Several of these get confused with each other, so each page ends with the symptoms it is most often mistaken for.
Bubbles, craters or pinholes
Round raised blisters, small holes, or dimples that opened while the coating was still wet. Usually air coming out of the slab, not air stirred into the resin.
Yellow or amber cast
A clear coat or a light color that has gone warm and dirty looking, worst under skylights, doorways and windows.
Sticky, tacky or still wet
Soft or fingerprint-tacky past the time it should have hardened. This is a cure failure, and it is the one most often mis-blamed on the product.
Chipping and flaking
Coating breaking away in small pieces at doorways, tire paths and edges, usually with clean grey concrete underneath.
Cracks
Lines running through the coating. What matters is whether the crack is in the coating alone or is the slab telegraphing through.
Slippery when wet
A smooth gloss coat with nothing in it to break the water film. The most fixable problem on this list.
Turning white or cloudy
A milky haze, chalky bloom or white patches. Often moisture, sometimes a surface reaction that happened during cure.
Peeling and delaminating
Coating lifting in sheets you can pull up by hand. The most serious failure, and almost always a bond problem underneath.
The pattern behind most of them
Three causes, most of the failures
Coating failures look like a long list until you sort them by root cause. Then it collapses into three, and two of the three happen before the first pail is opened.
1. Moisture coming up through the slab
Concrete on grade is a wick. Water vapor moves up through it constantly, and in South Florida it moves a lot. A coating is a vapor-resistant skin laid on top of that. If the vapor drive is higher than the coating can hold back, it pushes the coating off the slab or blooms underneath it. This one cause sits behind bubbling, peeling, whitening and a good share of chipping.
It is also the one nobody tests for. Moisture testing before epoxy covers the three tests worth running, and what a moisture vapor barrier actually does covers the fix.
2. Prep that did not open the concrete
Epoxy does not glue itself to concrete. It grips a mechanical profile, and that profile has to be ground in. Acid etching, pressure washing and a stiff broom do not produce one. Neither does grinding that stops at the sealer and never reaches sound concrete. If the coating is sitting on laitance, curing compound or an old sealer, it is bonded to a layer that is itself loose, and it will leave when that layer does.
How to prepare concrete for epoxy is the step most installers get wrong, and it is worth reading before you buy anything.
3. Mix ratio, mix technique or temperature
Two-part epoxy is a chemical reaction with a fixed recipe. Eyeballing the ratio, topping off a kit, failing to scrape the sides and bottom of the pail, or working outside the temperature window of the product all produce a floor that never reaches its listed properties. This shows up as soft or tacky coating, and sometimes as a surface that looks fine and fails under traffic a month later.
Every product we sell publishes its ratio, its pot life and its temperature range. They are on the technical data sheets, and they are not suggestions.
The honest answer
Fix in place, or grind it off?
We would rather sell you the right answer than the cheaper one, because the cheaper one usually comes back. The test is simple: is the coating that remains still firmly bonded to sound concrete?
| Symptom | Usual verdict | Why |
|---|---|---|
| Slippery | Fix in place | The coating is sound. It just needs texture and a wear coat over the top. |
| Yellowed clear coat | Usually recoat | The color change is in the top layer. Abrade and apply a light-stable topcoat. |
| Scattered bubbles or pinholes | Depends on area | A few can be cut out and patched. Widespread means the slab outgassed and the bond is suspect. |
| Cracks | Depends on the source | Coating-only cracks can be filled. A moving slab crack will come back through whatever you put over it. |
| Chipping at edges and traffic paths | Often localized | If the surrounding coating passes a scrape test, cut back to sound material and rebuild. |
| Sticky or uncured | Remove | Uncured resin never hardens with time. It has to come off before anything goes over it. |
| Peeling in sheets | Remove | The bond has failed. Coating over a failed bond buys a few months at most. |
| Widespread whitening under the film | Remove | Moisture is already between coating and slab. Nothing applied on top changes that. |
When the answer is remove, it means grind, and the machine matters more than the coating that follows. How to choose a concrete floor grinder covers sizing, and rent versus buy is an honest look at when owning one pays.
Doing it again properly
The build that does not come back
A floor that lasts is a stack, and each layer has a job. Skipping one to save a day is where most of the failures on this page start.
Test the slab
Before anything else, find out how wet the concrete is. If the numbers are high, the moisture barrier is not optional.
Grind, do not etch
Open the concrete with diamonds until you are into sound material and the profile is consistent across the whole floor, including the edges.
Barrier and primer
A moisture vapor barrier holds back the slab. A primer wets the concrete and gives the build coat something to grip.
Build coat
The 100% solids layer that carries the color, the flake or the metallic and does the structural work.
Wear coat
A polyaspartic or polyurethane top layer takes the abrasion, the chemicals and the light, so the build coat does not have to.
- Moisture Vapor Barrier
- Primers
- Epoxy Floor Coatings
- Polyaspartic & Polyurethane Topcoats
- Crack Fillers & Specialty Products
- Epoxy Flakes & Quartz
- Waterproofing Systems
One exception worth naming. An exterior deck, a balcony or anything over occupied space is not a floor coating problem at all, it is a waterproofing problem, and it takes a waterproofing system rather than a coating. Putting epoxy over a deck that needed a membrane is its own category of failure.
For how much material the stack takes, use the coverage guide rather than a number off a label, because coverage changes with profile, porosity and how much the slab drinks on the first coat.
Our position on material
If the material was the problem
A coating failure is nearly always a slab, prep or mix issue rather than a bad pail. When the material genuinely is at fault, we replace it free. Bring us the batch details and what happened and we will work it out with you. We are an authorized dealer for every brand we sell, so warranty and technical support run through us rather than through a third party.
Talk to somebody who has stood on a slab
Tell us what you are seeing
This page is general guidance. Every failure has more than one possible cause, and a web page cannot see your concrete. If you can describe the floor, its age, the prep and what the coating is doing, we can usually narrow it down fast and tell you honestly whether it is a recoat or a grind.
Latux Epoxy
2201 N Andrews Ave, Suite 108
Pompano Beach, FL 33069
(800) 413-1427
Monday to Friday, 8:00 AM to 5:00 PM.
Saturday by appointment.
Sunday closed.