A durable floor will require at least two layers of epoxy, which must be cured overnight between layers. Once the last coat has been applied, it's best to wait at least three days before allowing the vehicle to enter the garage; complete cure can take up to two weeks. For a typical car garage, two gallons of epoxy should be more than enough for two coats after applying the primer. Three gallons should cover an average two-car garage, and generally five gallons will be needed for a three-car garage.
If you opt for an epoxy paint for your garage, a 1-part epoxy paint will be your best option. It comes as a floor covering kit, saving you the stress of having to make sure you've bought the right supplies. It is a self-priming epoxy paint, soluble in water and easy to apply. As long as the previous layer has adhered very well, the preparation will be good and a new layer can be applied over it.
While paint only adds a temporary layer to concrete, epoxy actually builds up the floor and offers incredible protection. Do the same if you have a worn coating that adheres very well, but has some stains where the coating has worn down to concrete. We'll break it all down for you so you can learn about these garage floor coating options and the various advantages and disadvantages that come with them, such as the cost of an epoxy garage floor compared to a painted garage floor. Depending on the thickness of the application, a gallon of epoxy floor coating will cover between 300 and 500 square feet with a single layer.
The key to applying a new layer is to mechanically roughten the surface of the previous layer to create enough bite for the epoxy to adhere to it. If you want unparalleled protection for your garage's concrete floor, an epoxy coating system is the way to go. If the coating is quite worn out and looks more concrete than epoxy, then you'll want to start from scratch by shredding the floor. Once you clean the floor with denatured alcohol, you're ready to apply a new layer of epoxy or floor covering of your choice.
I did something similar, although I ended up dropping a 100% epoxy top layer and then a thin layer of polyurethane on top. This term is a bit confusing because people hear the word “epoxy” and assume that this type of paint is actually an epoxy floor coating. Sometimes it's as simple as when someone planned a multi-layer flooring system and waited too long between coats, leaving the epoxy to harden, before applying the next coat to obtain a chemical bond. The most common ones are for people who have already applied a layer of color and now realize that they want to get the shiny look and benefits of applying a clear coat.
As long as the existing garage floor covering is a 2-part resinous product, such as epoxy, polyurea, polyaspartic or polyurethane, you can apply an additional layer of a compatible product without problems. If you have an old transparent layer that you want to renew, you will first have to use 80 to 100 grit sandpaper or a 60 to 80 grit sanding screen to remove a small layer of the coating.