Epoxy Floor Problems
Epoxy floors provide a resinous, hard-wearing, high-performance overlay that protects concrete floors. The material is applied to floors to protect from chemical spills and splash, as well as immersive corrosion generated by manufacturing processes such as food and beverage, wastewater, or process water. These flooring applications have proven to be extremely important to the life expectancy of the manufacturing asset. However, when installed incorrectly, epoxy flooring can result in a lot of frustration and wasted effort. The team at Alpine Painting and Restoration want you to avoid these common epoxy flooring mistakes and problems so your project turns out perfect.

The Most Common Epoxy Flooring Problems
Installing epoxy flooring only takes a few steps, but there are a number of issues that can occur when it’s being applied. From air bubbles, to blisters, fish eyes, and blushing there are a number of outcomes that are less than perfect. Not only is a flawed epoxy floor a disappointment, they often can’t be fixed, and you’ll have to pay to have the floor removed and start over from scratch.
We’re going to outline all of the most common problems that occur with epoxy flooring, along with providing information about how to solve them should they occur during your project.
Air Bubbles in Epoxy Floor Coating
What causes air bubbles in epoxy floor coating? Bubbles are one of the most common issues that arise when installing an epoxy floor. Bubbles can be caused by excessive mixing with power tools, hot temperatures, incorrect application, and the presence of contaminants. As a result, air becomes trapped below the epoxy and rises during the curing process creating a solid bubble of epoxy.
Solution
Take care to not mix the epoxy and hardener too forcefully, otherwise too much air will wind up in the epoxy. After the epoxy has cured, bubbles are generally sanded off and then a new layer of epoxy is applied to the sanded surface.
Blisters and Craters in Epoxy Floors
What are blisters and craters in epoxy floors? Epoxy floors can develop both blisters and craters, ruining its traditional flat, smooth surface. Craters are typically caused by contaminants, anything left behind after surface preparation that prevents the epoxy from adhering to the floor.
Blisters in epoxy are the result of trapped air or outgassing. When epoxy is applied to porous concrete, air can rise up while the epoxy is curing, which forces the epoxy layer up, creating a blister. Both blisters and craters can be avoided by properly preparing the floor before applying the epoxy mix.
Solution
If your floor has blisters and craters, the blisters can be sanded off and the craters filled in with additional epoxy. If this is deemed insufficient, the epoxy will need to be removed and reapplied.
Film and Dullness
What causes dullness in epoxy floors? When an epoxy floor isn’t clear and shiny, excessive moisture is often to blame. When epoxy is installed during very humid weather (anything over 60% humidity) moisture can collect on the surface. When the epoxy is applied, that moisture is trapped resulting in a foggy, dull appearance. Be keenly aware of the weather when installing epoxy and if it’s too humid or wet out, reschedule or use a dehumidifier and heater to keep the area free from moisture. A cloudy or hazy epoxy flooring can also be caused by improper mixing, or applying the epoxy when the surface is extremely cold.
Solution
Epoxy floors with a dull finish can get their shine back through a few different solutions. In some cases, simply polishing the epoxy with water and a mild detergent helps. Sanding down the dull epoxy and applying a fresh topcoat is another solution. If the dull flooring simply can’t be salvaged, the epoxy can be completely stripped off and reapplied.

Epoxy Resin Yellowing
Why do epoxy resin floors turn yellow? Epoxy flooring can become yellowed as a result of direct sunlight, persistent moisture, heat, improper installation, or exposure to chemicals. It’s important to note that over a long enough period of time, all epoxy flooring will experience some yellowing. But when it’s exposed to certain elements the epoxy becomes noticeably yellow faster.
Sunlight, chemical reactions, high temperatures, and moisture can all result in epoxy becoming yellow. Leaving water on the surface of the epoxy for long periods (like rainwater), or frequent weather with higher than 80% humidity can cause epoxy to yellow.
Solution
Epoxy resin yellowing can occur due to exposure to sunlight, heat, or certain chemicals. To prevent yellowing, avoid prolonged exposure to sunlight and heat, and use epoxy products formulated to resist yellowing. If yellowing occurs, it may be necessary to repair or recoat the affected area to restore the epoxy’s original appearance.
Peeling in Epoxy Floors
Why does epoxy floor peel? Epoxy flooring can peel as a result of poor adhesion. Adhesion issues can have various causes. These include insufficient surface preparation, the presence of moisture, or contaminants like oil finding its way into the epoxy. These factors cause the epoxy to lift up from the floor, and peel.
Solution
If your epoxy is not adhering properly to the floor, it will likely need to be removed and reapplied.
Epoxy Resin Cracking
What causes epoxy resin to crack? Epoxy resin commonly cracks as a result of high temperatures. When epoxy is too thick and gets too hot, the result is that it can crack. If the temperature rises while the epoxy is curing it will expand and contract, resulting in cracks. When a thick layer of epoxy is applied it will trap in heat, which can cause it to expand and crack.
As with all epoxy flooring projects, it’s important to keep an eye on both the temperature and humidity, both of which can damage the epoxy while it cures.
Solution
If cracking occurs you can fill the cracks in with epoxy and recoat the affected area if needed. Cracks will likely be obvious and not obscured as well as more minor epoxy issues. Cracks could also represent a safety hazard, which would make replacing the epoxy floor a good course of action.
Curing Issues in Epoxy Floors
What are the possible curing issues for epoxy floors? After an epoxy coating is applied to the floor it has to “cure” and become solid. There are many factors that can prevent the epoxy from curing properly, which will result in a floor that needs to be repaired or replaced. Having the proper resin to hardener ratio is critical. If there’s not enough hardener, the epoxy will never cure. If there’s too much hardener, the floor will be brittle and crack.
Temperature and humidity are huge factors in curing. If the temperature rises too quickly, the epoxy can crack. If it’s too humid, moisture can get into the epoxy resulting in blisters and bubbles. With enough moisture the epoxy will never cure properly and be soft and tacky to the touch.
Solution
If an epoxy floor doesn’t cure properly, it has to be removed and reapplied. There’s not a way to address any of the curing issues after the fact. Make sure you apply the epoxy when the weather isn’t too hot or too humid, and double-check the mixture to be certain the ratios are correct.

Additional Epoxy Flooring Problems
Not all epoxy floor problems are as noticeable as peeling and blistering. Other common problems regularly occur from lack of applicator detail and precautionary steps. Experienced epoxy floor workers know how to prevent these other common issues.
Tacky Surfaces and Soft Areas
What causes a tacky, sticky epoxy floor? Epoxy flooring can have tacky and soft areas when it fails to cure properly. The curing process can be thwarted by low temperatures, high humidity, chemical reactions, or foreign substances. Instead of a smooth, solid floor, the epoxy will be sticky and soft. Tacky flooring can also be caused by an improper mix of epoxy and hardener.
Adequate surface preparation and avoiding humidity and moisture can help prevent a tacky, uncured epoxy floor.
Solution
To fix an epoxy floor that won’t cure properly, unfortunately the epoxy needs to be completely removed. You can then reapply the epoxy and try again.
Surface Blushing
What is surface blushing? Surface blushing is a greasy, hazy film that can occur on the surface of epoxy floors. Blushing is caused by high humidity or a chemical reaction during the curing process. Surface blushing results in milky or cloudy spots on the surface of the epoxy. The good news is that surface blushing isn’t permanent and can be scrubbed off with warm soap and water.
It’s important to remember that surface blushing must be removed before applying any additional coats of epoxy. Otherwise, the blushing will be trapped beneath the additional topcoat, and can’t be removed.
High humidity can result in surface blushing, so avoid applying epoxy in very humid weather, or use a dehumidifier or space heater to reduce the moisture in the room. Incorrect epoxy mixing can also cause blushing, so be sure to use the proper mixing ratios.
Solution
When surface blushing occurs, wipe down the epoxy with a dry paper towel to remove it. Then wash the surface with warm water and a non-abrasive sponge or towel. After the blushing has been completely removed, you can apply a topcoat or additional layer of epoxy if needed.
Lack of Uniformity
What does it mean to have a lack of uniformity in regard to epoxy flooring? Lack of uniformity means that the final look of the epoxy has streaks, uneven thickness, bubbles, holes, and generally isn’t a smooth and shiny surface. Lack of uniformity can be caused by any number of conditions. An improperly prepared surface, mixing incorrect ratios of epoxy and hardener, using cheap or low-quality epoxy, unevenly applying the epoxy with the applicator, improper curing, and high humidity can all contribute to an epoxy floor with an inconsistent appearance.
Solution
There’s no single solution to fix a lack of uniformity with an epoxy floor, you’d need to address each individual problem. If there are bubbles or fish eyes, you can follow the instructions in this guide to fix them. If the epoxy floor seems like it would be too much work to save, you can remove it completely and start over.
Incorrect Mixing Ratios
How do incorrect mixing ratios impact epoxy flooring? For an epoxy flooring project you’ll need to mix the epoxy resin and hardener in the correct ratio. If you don’t get the ratios right, the mixture will never cure, leaving you with a soft, rubbery floor. If you add too much hardener to the mix, the result will be a weak and brittle floor that will chip and crack easily. Using the right tools and mixing the resin and hardener properly are one of the most important steps in applying an epoxy coating to your floor.
Solution
Unfortunately, there’s no way to fix an epoxy floor if the resin and hardener have been mixed improperly. The flooring will have to be removed completely. Take great care, follow the instructions, and make sure you get the ratio right before you begin.
Fish Eyes
What are fish eyes in epoxy flooring? “Fish eyes” are pockmarks, or small indentations in dried epoxy that resemble a fish’s eye. They’re the result of epoxy being applied to a surface that wasn’t completely clean. Oil, grease, silicone and other materials that aren’t removed during surface preparation will prevent the epoxy from bonding properly, resulting in fish eyes.
Solution
Remember that proper surface preparation will help you avoid fish eyes or pinholes in your epoxy. Preventing the development of a fish eye is much easier than fixing one. Once a fish eye is created it can be covered up, but not completely fixed.
Pouring epoxy into the pinhole and then smoothing it over with a squeegee can reduce the appearance of fish eyes, but not remove them completely. An additional layer can be placed on top of the original epoxy as well. In some cases the epoxy can be stripped off the surface and reapplied to eliminate any fish eyes.
Moisture Buildup
Why is moisture buildup a problem for epoxy flooring? Moisture and humidity create big problems for epoxy. They can cause the epoxy to bubble, be dull and cloudy, or fail to set properly. High humidity and water need to be kept away from epoxy flooring projects to ensure a good outcome. High humidity can bring moisture, but so can big changes in temperature. If the temperature goes down quickly while you’re working, condensation from the air can become trapped inside the epoxy and create bubbles. Moisture in a concrete floor can also interfere with epoxy. If there’s not an adequate vapor barrier separating the concrete’s underside from the ground or the basement, moisture can rise up and get into the epoxy as well.
Solution
You can avoid moisture buildup in your epoxy flooring project by ensuring there’s proper ventilation, surface preparation that removes any moisture from the floor, and avoid installing epoxy when there may be a large drop in temperature, or there’s high humidity. If moisture does find its way into the epoxy, you can refer to a solution for the problem it causes, like fish eyes or bubbling.
Lumps, Globs, and Bumps in the Top Coat
What causes lumps, globs, and bumps in epoxy flooring? The primary cause of lumpy epoxy is that it wasn’t mixed properly. Much like poorly-mixed pancake batter results in lumpy pancakes, epoxy that isn’t completely mixed will create lumpy flooring. Those big globs are pure epoxy that weren’t broken down during the mixing process, or they could be the result of using dirty mixing equipment.
Solution
Lumpy epoxy can be avoided by thoroughly mixing the epoxy and hardener together prior to application. Once the lumpy epoxy has cured, you have two options. You can either sand down the lumpy parts and add an additional layer of epoxy on top. If the lumps and bumps are too severe, you may have to strip the epoxy off of the floor and reapply it.

Contact Alpine Painting and Restoration for your Epoxy Flooring Project
Epoxy is an attractive and cost-effective flooring option that will look great and last for years. Our licensed professionals know the ins and outs of epoxy flooring and they’ll make sure your project looks great with no issues.
We serve Philadelphia and the greater tri-state area with a wide variety of epoxy floor finish services. We’re skilled and experienced with the latest epoxy products and application procedures that will get you the best results. To learn more about epoxy flooring, call Alpine Painting and Restoration today at 215 348-4410 or contact us online.
Last Updated: October 10th, 2024