The preparation is everything when it comes down to anything regarding paint, especially concrete floor paint. The reason for this is because the surface you are placing the paint will be moving unless the substrate itself is there for good that is. So basically, this means that if the surface or the substrate you are painting moves or crumbles, then the paint will also move and crumble with it. However, there are different methods out there that you can use to help prevent the substrate you are applying paint on from moving. This is especially critical for new floors and when you need to paint them that you will have to do some extra preparation work to ensure the paint will look good and so that the substrate will not move. New floors, especially concrete floors tend to be fairly dust for awhile until the dust is removed by simple use of the floor such as driving on it, walking on it, and doing different activities on it. So you will have to ensure that the concrete floor itself is spotless and that the latent is removed before applying your paint and top coat otherwise it will break away from the actual substrate.
There are quite a few different methods of attack when you are trying to clean the concrete floor, and you can use products such as alkaline degreasers or a high pH degreaser to remove all of the oil and greases. Then once you are finished with that, you will need to use a low pH cleaner that is acidic to remove the particles and minerals found on the floor. A good acidic cleaner should contain some ingredients such as water softeners, rinse agents, and detergents to provide the best clean possible. And after using the cleaner you will need to reduce the pH levels on the floor, and this can be accomplished by a simple scrub rinse, but you are not ready for painting just yet.
You will need to pressure wash the floor next, but you may notice that there is still some road film on the floor; so before you do painting, you will need to remove that. The most effective method of removing this road film is to use contact, but and it is better to be very aggressive with the contact as well to break away the smaller particles that are stubborn, then you are ready for floor paint. And that is how you prepare a concrete floor for painting.