Almost every argument you will read online sets these two up as competitors. They are not. They are two layers of the same floor, and the companies pushing one against the other are usually trying to sell you a floor with a layer missing.
Epoxy is a thick, slow-curing resin that soaks into properly ground concrete and grabs it. That is its job: adhesion. It is also the layer that carries the moisture vapor barrier, because it can be built up thick enough to block vapor coming up through the slab. What epoxy is bad at is everything on the surface. It yellows in UV light, it scratches, and on its own it lifts where hot tires sit.
Polyaspartic is a fast-curing polyurea. It is harder than epoxy, it stays clear in sunlight, it shrugs off chemicals and it does not pick up under hot tires. What it is bad at is being a base coat. It cures so fast it does not have time to penetrate the concrete the way epoxy does, and it is not the right film to carry a vapor barrier.
Polyaspartic cures in hours. So if you use it for every layer and roll it straight onto the slab, you can grind in the morning and be done by dinner. That is the entire business model behind a same-day floor, and it is a real product. It just has no vapor barrier.
Concrete that sits on dirt moves moisture upward continuously. With nothing blocking it, that vapor collects under the coating film and pushes. You get bubbles, then edge lift, then sheets coming up where the tires park. Two to four summers is typical. The floor did not fail because polyaspartic is bad. It failed because the layer that stops vapor was never installed.
Those are a thin water-based epoxy over an acid-etched slab. Acid etching does not produce a real profile, the film is a fraction of the thickness, and there is no top coat. It is the cheapest version of the same mistake.
If a company gets uncomfortable at question two, you have your answer.
They do different jobs. Epoxy is the better base coat because it bonds into the concrete and carries the vapor barrier. Polyaspartic is the better top coat because it is harder, UV stable and resists hot tires. A good floor uses both, which is what we install.
It can, and that is exactly what a one-day floor is. It skips the vapor barrier, which is the layer that keeps slab moisture from pushing the whole system off.
On an interior floor with no moisture and no vehicles, sometimes. In a garage it yellows in sunlight and lifts under hot tires, which is why it needs a polyaspartic top coat.
Tell us the room, the rough size and your town. You get a written price, not a two-hour pitch. Fastest way is to text a photo of the floor to (815) 585-1750.
