Concrete is an amazing product. It has been used for centuries and its origins date back to 300 BC. Although there are reports that the use of concrete preceded this time, the first to use concrete effectively were the Romans. Ancient Rome had an abundance of ash, lime, and water, the key ingredients. Ancient master builders built cities and advanced culture as a result. It could easily be argued that without concrete we would still be living in tents. Humans would not have progressed to where we are today.
However, concrete is not without its flaws. The garage floor is a perfect example. Many houses were built with spancrete. Spancrete are precast concrete panels that are typically 24 feet long, 3 feet wide, and 6 inches thick. They are placed on the foundation of a house above the basement. Then concrete is poured on top about 4 inches thick. The problem is that this top layer of concrete cracks from settling right where the spancrete panels support each other. In the main part of the house this is not a problem, but it is a problem in the garage.
There are some forces at work that are a headache for a homeowner. Let’s start with a crack in the concrete garage floor first. When a car enters with snow or rain dripping onto the surface, it works its way into the crevice along with de-icing salts. The salts quickly eat up concrete, causing decomposition. If there is a spancrete underneath, the water will drip into the basement. The result is a damp, moldy and unsanitary space. If the concrete is level, the water will run down the crack and go under the slab. Once it’s frozen, it picks up the slab and then steps back when it thaws. This constant movement is not good.
Many attempts have been made over the years to create coating products and systems that combat this problem. Like everything in construction, there are right and wrong solutions. The first obvious solution is to fill in the cracks inherent in each concrete garage floor. However, what you don’t see is that the crevice walls are probably damp. The reason is that concrete is porous. Water from the surface drips into the crack and moisture vapor, if the slab is level, will push up. The only crack filler that works is a polyurea that dries below the surface. The polyurea must be fluid enough to flow to the bottom of the crack and fill all of the void to the surface. The wrong filler will never dry out and will stay soft and moist forever. Unless this critical step is done correctly, you will never solve the problem.
Coatings are the logical topical solution, but very few work. Unless the garage floor is properly prepared and an expensive epoxy, you run the risk of delamination being applied. You may have seen chipped and delaminated epoxy coatings. Sometimes they are applied incorrectly or are not of high quality. With all the factors at play that can cause problems, only the highest quality stands a chance.
In recent years, state-of-the-art polyurea and polyaspartic products have been developed that can withstand the harshest conditions. However, not all mixes are created equal and not all applicators have the knowledge or equipment to handle these high performance exotic mixes.
The proper process is to grind the concrete surface removing all possible bond breakers and opening the pores on the surface. The new Pure Bred products will really absorb into the top layer of the concrete and set when they dry. This makes the coating part of the concrete rather than just sticking to the surface.
As the coatings are applied, typically a total of 3-4 layers are created, with anti-slip particles added to each layer, a very durable surface is created. Even floors that seem hopeless can be restored to showroom condition and will work for the long haul. They are not just the right polyureas, but the ones that are in the hands of a professional. Of course, who really qualifies as a seasoned professional, and how do you know you’ve hired the right one? That’s for another article.
