Many garage owners find that their garages suffer from worn and pitted concrete with only half of the original garage floor paint left due to peeling. As many garage owners know, there are difficulties with getting epoxy floor paint to adhere in this environment.
Although many epoxy floor paint kits enable a lot of garage owners to paint their garage floor by themselves, many problems can still occur if correct preparation doesn’t take place. Old and flaky paint is a common feature that usually occurs due to the lack of surface preparation. Therefore, it is important for garage owners to not only understand what the best epoxy floor paint for a garage floor is but also the importance of correct surface preparation.
Epoxy floor paint needs a clean and porous surface in order to bond to concrete, Without this, it is almost guaranteed that your coating is going to fail at some point. In order to achieve the correct surface, preparation, in the form of acid etching of the concrete, needs to be done. Shot blasting or grinding of the concrete are preferred methods. however, for these methods, we recommend using highly skilled specialists/contractors to perform the grinding as the concrete can be easily damaged.
Why Your garage floor paint is peeling
There are several possibilities of this:
If this is the case, you should be able to check for this by looking at the bottom of the peeled paint. If it is covered with a layer of dust/dirt/grit, then that is the reason for the failure. Dust signalises that the floor wasn’t prepared well enough when the paint was applied to your garage floor. Weak crumbling concrete garage floors can be rectified through the use of a floor primer – this will consolidate the surface to become suitable for the epoxy floor paint to have something to bond to. However, it is highly recommended to prepare the surface, especially if the surface isn’t sound, before applying epoxy floor primers.
Water under the peeled epoxy indicate a damp or wet concrete surface during the application of the epoxy floor paint (some epoxies bond better than others to damp surfaces) or that water is actually migrating through the concrete flooring. It is impossible for water to evaporate through the epoxy; any moisture within the substrate of the concrete will create hydrostatic pressure that will eventually cause enough pressure to lift the epoxy floor paint right off the surface. Generally, moisture issues need to be rectified before any coating can be applied to the floor.
Epoxy floor paints could also fail due to some sort of surface contamination and again, inadequate surface preparation. Most industrial epoxy floor paints will not stick to oil, grease, wax stains and spills or even to previously applied sealers containing these products – these may have been applied by a past owner. Contamination isn’t always what you see at the surface level, it can also occur within the substrate.
Concrete is very porous. If water is spilt onto concrete, 95% of it will soak into the substrate. The water will then rise to the surface and evaporate, leaving dry concrete. However, oil will never evaporate. Cleaning the surface of oil will only be a temporary measure as the oil within the substrate will rise and the surface will be dirty again. Application of epoxies or floor paint over an oil contaminated floor will only make the oil rise faster. Please note that acid etching will not remove silicone and tyre polymer residue, these areas will need to be treated through grinding. This is because acid needs to react with the free lime within the concrete for it to work properly. The oil on the surface will have no chemical reaction to the acid and as a result, you will have a poor surface profile. Degreasing of the area and sealing/priming it with a primer that is specially formulated to adhere to oily surfaces will help to solve the problem.
Residue from acid etching of the surface
Acid etching of garage floors works by reacting with the free lime in the concrete. This results in a breakdown of calcium at the surface, exposing the pores of the concrete. Calcium is then deposited onto the surface forming a fine layer of dust. It is therefore very important that the dust is effectively removed, either through sweeping, vacuuming or pouring liberal amounts of water to flush the surface (be sure to leave the concrete to dry and test the moisture of the surface before applying primer and epoxy floor paint). The dust prevents the epoxy floor paint from adhering to the surface by sticking to the dust instead, eventually peeling up.
A sealed concrete floor
Epoxy floor paints will not adhere to concrete that has been previously sealed. Acid etching of the surface will not remove a sealer; the only way to make a previously sealed garage floor bond with epoxy correctly is by grinding the surface. This removes the sealer and gives you the added benefit of preparation of the concrete.
Testing for a sealed surface only requires water droplets spread around different areas of the concrete. Beading of the water droplet indicates a sealed surface whereas water that turns dark and is absorbed into the concrete shows otherwise. To conduct a stronger test (and to avoid inconclusive evidence) use muriatic acid. If this forms a bead on the surface like a drop of water, the concrete is sealed, otherwise, the acid should react with the concrete by fizzing.
Excessive amounts of Laitance
The weak top layer of concrete is known as laitance. This is produced by excess bleed water when trowelling the finish, or through the spraying of extra water, a method commonly used to smoothen the concrete. Concrete dust is a clear sign of excess laitance. To test for laitance that isn’t visible in the form of concrete dust, we recommend using a screwdriver to scratch the surface. The screwdriver should glide across the concrete without it crumbling or loosening any particles.
Removal of the weakened layer can be achieved through the grinding of the surface, this will ensure that the surface is properly prepared for coating.
It is important to know that cheap garage floor paints will not be able to withstand high-traffic areas and will eventually become worn where the concrete is visible. This, however, is a result of abrasion and not peeling of the floor paint. Less expensive products are also prone to hot tyre pickups (this is where the heat of the tyre lifts the epoxy coating from the concrete floor) this is not necessarily a sign of poor floor preparation and is likely to be due to the low solids content in the epoxy.
Most of these common problems with the peeling of epoxy floor paint can be avoided through correct floor preparation, priming and the use of high-grade epoxy floor paints that are the best paint for garage floors.