Concrete, Flooring, Specialties

Six Reasons Why Epoxy Floors Fail

Six Reasons Why Epoxy Floors Fail

Epoxy floors are a great solution for special-purpose commercial and industrial floors that need a seamless barrier between the work environment and the subfloor below.  Depending on the specific formulation and composition, epoxy flooring can be used to provide an environment that meets specific hygienic needs, resistance to acid and industrial chemicals, durability to wheeled and forklift traffic, waterproofing, and more.  But like most professional specialty products, it requires a great deal of care to properly install.  The key to the success of any flooring type – not just epoxy – is completely in the installation.  Just as it takes a good tailor to make sure that your new suit fits, it takes a good installer to make sure that your new floor does too!

These six reasons are some of the most common causes of epoxy floor failure:

1.  Poor Surface Preparation.

A strong bond between the new epoxy and the existing floor is essential to the successful installation.  Your existing surface must be made pristine in order for the epoxy to bond properly.  To get an existing surface into installation-ready condition, we suggest diamond grinding or shotblasting the subfloor to remove all old flooring.  The installation surface must be clean, dry, and completely dust-free – otherwise your new flooring is just bonding to the contaminants on your floor, not the subfloor itself!

2.  Too Much Humidity.

Once you’ve taken care of any mechanical contaminants (like dust or dirt), now you have to take care of the other major bond breaker for epoxy:  too much moisture!  Solvent-based epoxy products do not bond well with moisture present; excessive humidity can cause a substantially weaker bond between the epoxy and your subfloor, or prevent a bond from forming at all!  It’s pretty simple to prevent humidity from becoming a problem:  1) make sure your floor is completely dry, 2) ensure that there are no dripping pipes or leaky taps, and 3) ensure that there isn’t too much riding humidity coming up from the earth below your foundation.

epoxy floors

3.  Weak Substrate.

Just as a master chef is only as good as his ingredients, an epoxy floor is only as good as the substrate it’s installed over.  Sometimes if an epoxy installation fails and separates from the subfloor, the epoxy itself is misdiagnosed as the problem.  In some cases, what has actually happened is that the epoxy bond is stronger than the low-quality concrete it was installed on – the concrete has separated from itself!

4.  No Primer, or Wrong Primer.

In many ways, epoxy is similar to paint:  it goes on in a liquid form, and develops over time into a solid surface coating.  And just like paint, using the correct primer to help the epoxy bond to the subfloor is essential to get good, strong adhesion.  Commercial and industrial floors experience a tremendous amount of wear and tear, and it’s essential to ensure that the correct primer is chosen to match the specific needs of your substrate.  Don’t just assume that the industrial floor screed will stick well enough!

epoxy floors

5.  Incompatible or Inappropriate Substrate.

Epoxy floors are tough, but they can’t compensate for an inappropriate substrate – like wood.  Wood is never a suitable subfloor for an epoxy installation.  The adhesion ability and the tensile strength of a subfloor must be taken into consideration when evaluating a subfloor’s suitability.  Plywood subfloors are far too flexible for epoxy, and the expansion and contraction they go through during temperature and humidity variations are too much movement for an epoxy to successfully withstand.  This leads to tearing, peeling, and cracking – and ultimately failure.

6.   Contaminated Retrofit Floors

The problem of a contaminated existing floor is common in buildings that have specialized uses with a failed existing floor, like food and beverage factories, automotive repair garages, industrial chemical plants, etc.  In cases like these, special preparation must be carried out to ensure that any contaminants that would cause the epoxy to fail are either removed or completely remediated before the new floor is installed.  Any and all oils, greases, and residues must be completely cleaned off and neutralized before the new epoxy is installed.

12 thoughts on “Six Reasons Why Epoxy Floors Fail

  1. Every epoxy lover should know why fail epoxy. Very informative post. Thanks.

  2. Paul honeyman says:

    I have a wooden floor at home. Am I able to reinforce the floor joists, put down tile hardbacker or other cement board to provide a suitable substrate for an epoxy floor?

    1. Ross Ferguson says:

      Thanks for your message! We do only commercial flooring – unfortunately, we can’t offer any advice on residential projects. Sorry!

  3. Bradfields says:

    Thanks for the tips. It looks like preparing the surface correctly is key.

  4. Very impressed with the content in this article. I think that the number one perpetrator here is the poor surface preparation. I have so many people call me to come take a look at a job they tried to do themselves and I can almost always tell right away that it was poor surface preparation. This is great information and a must know for everyone considering getting into epoxy flooring. Thanks again!

  5. Don Pfleger says:

    Hello. Had an epoxy flake floor in basement in which the sealer or combination of epoxy/sealer was not dry after 10 days. It is possible this system would have “cured out” after 6 weeks, which is what my contractor is telling me?


    1. Ross Ferguson says:

      Unfortunately, it’s really hard to generalize about these kinds of floors. Your best bet would be to contact the manufacturer directly with the exact specs of the epoxy system used and get their input.

  6. Jhon Roberts says:

    I knew that, thats why epoxy coating for me, are not a good options, there are too many variables which can fails.

    I trust polished concrete for me industrial floor, easy to apply and cheaper.

    thank for your advise!

  7. Sarah says:

    Could i cover decorative wood with epoxy? like salvaged lathe that’s arranged in a pattern and then covered with epoxy so you can still see the design,but the floor is now sealed?

  8. Several of the comments above hit the nail on the head: the number 1 reason why epoxy floors fail is due to poor preparation followed by the wrong primer or no primer.

    Thanks for sharing

  9. Evan Oakes says:

    Nice reading your content here. I did try garage epoxy flooring in our home, I think in addition no matter where you add epoxy coatings, a few drawbacks come with it. First, moisture levels in a floor can affect the durability of an epoxy product. Because the material doesn’t breathe once it cures, any moisture trapped below the surface can be a problem as it evaporates. This was based on my experience. Thanks for sharing.

  10. Prep always makes the biggest difference. I love the look of epoxy floors, but I always advise about how important the prep is! Love seeing this important info out there!! 🙂

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