Take a look at this image and you’ll see that the epoxy has delaminated from the floor in an upward motion. Notice the underside of the piece of epoxy the person is holding and you’ll see the top layer of the concrete slab stuck to the underside of it, notice the granularity of the concrete. The culprit here is the concrete letting loose! This is one of the best examples of sandy or granular concrete we have seen. Usually caused by the contractor using too much aggregate/sand to save some money. The other issue here maybe that there was moisture in the floor and that the moisture pushing up on the epoxy had enough pressure to cause the weak concrete to let loose.
Here’s another example of why you can experience peeling of your epoxy. Although this is not common some floors were poured with a high content of river stone/pebbles also known as pea gravel floor, again most likely due to the contractor trying to save money on the job. See all those black spots they are pea gravel/pebbles that are very smooth and are not porous whatsoever which means its very difficult to get anything to stick to it. If you have this type of concrete you must use the Bonding Primer to ensure adhesion to these types of concrete floors. The above floor where they used too much sand is different as the surface is more granular and loose. This floor is hard and very smooth almost like a polished floor so you need the Bonding Primer as opposed to the sandy floor you need our Standard Primer or better yet our High Solids Primer. Our High Solids Primer is amazing and better than most actual epoxies on the market.
So how do we try to prevent this from happening ? First thing is to always make sure your concrete is 100% dry after etching. We recommend a minimum of 24 hrs to 48 hrs depending on temperature and humidity. If the humidity is very high when you’re floor is drying it will take longer for that moisture to evaporate out of the slab. Secondly take a good look at your floor and if you notice that there is a lot of exposed aggregate or it has sandy type of texture to it use a primer. Our Epoxy Flooring Primer will penetrate into the slab, getting in between the tiny spaces in the aggregate binding them together which greatly strengthens your slab. Also sometimes contractors use pea gravel which are small round stones that are very smooth. This is also a good candidate for the top layer of the concrete letting loose. If you have a pea gravel floor use our Bonding Primer that will bond to the smooth surfaces of the pea gravel thus ensuring a solid bond between your floor and the epoxy.
The good thing is that these types of situations are rare, so chances are you don’t have to worry about this but if you have any doubts just send us a picture and will let you if there’s anything to be concerned about and guide you accordingly. We’ll make sure you use the necessary products so that you don’t have any issues.