FAQ- What is the Major Cause of Premature Coating Failure on Concrete
By John Bennett, CEO, Eco Safety Products

What is the Major Cause of Premature Coating Failure on Concrete?
While there are many application and substrate variables that may lead to premature coating
failure, the single most important prevention is proper surface cleaning and preparation to ensure
optimum lifespan of your coating project. This process is often viewed as insignificant cleaning
and you want to get on with the artistic work. This is by far the least glamorous, and the urge to
take shortcuts is tempting. If you are a contractor, time is money and the client has a deadline
of yesterday. Or if you are a Do-It-Yourselfer (DIY) and excited to get the project done and you
just can’t wait to see the finished product. Trust me, once you invested time, money, and sweat the last thing you
want is a “redo” anytime soon. Take extra time now for this process and save time, money,
body/headache over the long run. Keep in mind that the overall success and performance of stains,
sealers, and other coatings on new or existing concrete substrates are highly dependent on the
quality and attention to detail during the surface preparation process.

When installing a penetrating decorative concrete stain such as SoyCrete™, you will find that the
extra detail will provide you with more decorative and artistic options, not to mention a more
beautiful end project. The main objective is to achieve the highest degree of cleaning and surface
profiling that will allow the chosen coating material to reach its optimum penetration and/or
bonding strength that is equal to or exceeds the tensile strength of the substrate that the
material is being applied to. If there are limitations to performing thorough surface preparation,
you must be prepared to accept a lower expectation level of the coating lifespan.

For instance, if you install a coating over dust and dirt, you are bonding to dust and dirt which
has zero bonding strength to the concrete. Likewise, if you install a coating over an existing
coating that has a weaker bond than the new coating or one that is already beginning to flake, your
new coating will only be as strong as what it is applied to. When that area gets enough abrasion
(very little) the coating will come up. If you are applying a penetrating stain which needs to
penetrate into the surface for long lasting results without ever peeling but you fail to properly
open the pores to allow penetration, it will reside on top with a weak film and will wear
prematurely. If you stain or coat over efflorescence, you are simply attaching to loose soluble
salts that will easily be removed through abrasion. On the other hand, if you have a thoroughly
cleaned surface with optimum porosity, whether you are installing a penetrating stain or a topical
floor coating, the material will achieve maximum absorption and will bond more deeply within the
substrate providing significantly longer life span than one having a weak grip on a non-porous
surface.

What to Look For: Thoroughly investigate the surface for contaminants, defects, internal
contaminants, bond breakers, and potential moisture vapor transmission problems. Look for signs of
dusting, cracking, efflorescence, water, oils, curing compounds, form release agents, and laitance.

New concrete is not an excuse to overlook detailed evaluation and preparation. Curing compounds are
liquid materials that are commonly applied to newly placed concrete to allow hydration curing by
retarding water from evaporation. If it hasn’t dissipated or is not removed, this will be a bond
breaker. You may also find form release agents which are applied inside the forms to facilitate the
release and removal of the forms. These release agents do not allow the forms to stick, thus will
not allow materials to absorb or bond as well. Additionally, the density or porosity level of the
concrete will vary by the type of concrete mixture and the finishing method used. Laitance (a thin,
weak cement layer of partially hydrated cement paste) also leads to premature failure as these areas have a weak bond.