In our opinion these products are nothing but glorified water based porch and floor paints. They hold up fine until it comes to hot tires or anything that drips from your car like oil, antifreeze or gasoline. They usually come with directions that tell you to use a cleaner degreaser which is simply not enough preparation for the traffic of a garage floor. If you have a previously painted floor, all the paint must be removed to insure proper adhesion. The concrete must be ground down or etched to make it porous enough to be coated properly. There are a couple of choices that you have to achieve the proper porous state. One option is to utilize paint removers, which generates fumes as well a big mess, but the industry preferred method is to remove the existing coating mechanically by grinding or shot blasting. The mechanical methods, which is used by Granite Garage Floors, both remove the paint and grind the concrete. If you choose the paint remover route, you must still acid wash the concrete floor which comes with its own set of issues see (Grinding vs. Acid Etching). Remember, these epoxy coating products are only as good as the surface they are being applied to and, without a properly prepared surface, it will be very difficult to achieve the long-term durability and protection of a professionally installed garage floor coating system. In our opinion, the preparation is the most critical step of the entire process.