Why Is My New Epoxy Garage Floor Peeling?

eople often tell us their newly installed epoxy garage floor peels after only a year. Most of the time, they blame the product applied, but the truth is that, more often, the reason why is something else.

Let's start by saying that the most significant complaints come from DIY applications. The reason is that DIY epoxy kits only give instructions on applying the epoxy to your floor but not how to prepare the epoxy.

Floor prep is crucial to a successful epoxy floor installation. Without it, the floor will fail soon after the new epoxy has been laid out.

Reasons why your epoxy floor has failed

Let's look at the most common reasons why your epoxy floor peels and how to prevent them.

Concrete Floor prep

Floor prep is the key ingredient to a successful and long-lasting epoxy floor. Epoxy needs clean and porous concrete to sink into and bond to it. If the concrete pores are not opened enough or are overly exposed, the epoxy will not bond. The same is true if your floor has any residue from acid etching, oil stains, dirt, or grime.

Concrete grinding achieves the best concrete surface profile, which is not available in many DIY attempts. At the very least, the concrete should be acid etched, which, again, for inexperienced installers, can cause more damage than good.

No matter how high-performance epoxy you apply to the floor, if the concrete is not prepared right, the epoxy will not bond and peel off soon after the application.

Soft concrete surface

Soft concrete can be caused by lousy mixing, pouring, or both. It is distinguished by dusting, crumbling, or easily chipped and scratched concrete.

The best way to prepare soft concrete for epoxy is to grind it and apply a densifier. The densifier fills in the concrete pores and increases the concrete surface density. However, depending on the quality of the concrete slab, even this might not help.

If you suspect you might have soft concrete in your garage, we recommend contacting a flooring professional to inspect the floor and, if feasible, complete the job.

Moisture

Moisture trapped in the concrete is one of the most common problems associated with epoxy peeling.

As epoxy creates a thick plastic-like film over the concrete, any water trapped inside the concrete cannot pass through the epoxy. This results in water vapor creating intense pressure to lift the epoxy coating on its way out.

If your concrete has any dark spots, your slab has not fully dried. This happens with newly poured concrete or in houses where underground moisture soaks into the concrete.

If you are considering epoxy flooring but have doubts about moisture, it's best to do a moisture test on your concrete first.

Acid etching

Acid etching is a method of floor prep used mainly by DIY projects. It works by using acid to open the concrete pores. The acid reacts with the free lime in the concrete to break down the calcium at the concrete surface. The calcium turns into very fine dust, which sits atop the concrete. If it's not removed correctly, it can prevent the epoxy from bonding with the concrete and instead of sticking to this fine dust, the epoxy peels off.

If you decide to use acid etching for the floor prep, you should not let the floor fully dry during the process. Instead, wash off the residue with plenty of water and a deck brush. You might have to repeat the process several times depending on how much free lime there is. A pressure washer works best for cleaning the fine dust from your concrete.

Sealed concrete

Many people attempt to apply epoxy or floor paint over sealed concrete. This will not work; as previously mentioned, epoxy needs to penetrate the concrete to bond with it.

If you are unsure if your concrete is sealed, you can do a simple test: Drip water over various areas of your concrete. If the water sits on top of the concrete without being absorbed, your concrete has been previously sealed.

If you want to apply epoxy, you'll need to diamond grind the concrete to remove the sealer and open the concrete pores simultaneously.

Do not attempt to use acid etching, as the acid will just sit on top of the sealer without actually removing it.

Oil and contaminants

If you are like us and love repairing your car in the garage, then you know how annoying oil stains, silicones, and polymer tire residue are.

As these contaminants soak into unsealed concrete, they can prevent the epoxy from bonding with the concrete.

Areas with oil stains are usually darker than others; the darker the area, the more oil is soaked in the concrete. In cases like this, it is better to absorb the oil before grinding off the concrete. The easiest way to remove minor, stubborn stains is to use a poultice.

Soak an absorbent material, such as cat litter or sawdust, with acetone or lacquer thinner. Spread it over the stain and cover it with plastic. Leave it overnight. The solvent will break down the oil, and the absorbent material will suck it out of the concrete.

After grinding the concrete, you should test the areas where there were oil stains or tire markings. Drip water over them. If the water is absorbed, the epoxy will bond with the concrete.

Note that acid etching is unsuitable for removing oil stains or contaminants from the concrete slab.

Conclusion

Applying epoxy flooring that lasts years is not difficult. It requires attention to detail and knowledge of how the concrete floor should be prepared and tested.

With the exception of moisture issues, all other problems can be ground away. With the proper technique, we can guarantee you will have an epoxy floor that lasts years.