Depending on what the floor is made of and whether it's interior or exteriors, a variety of coatings are commonly used including latexes, alkyds, polyurethanes, and epoxies. Changing coatings technologies means changing your thinking and maybe the products you use. Today he'd choose latex. Painting wood floors, porches, balconies, or decks pose their own problems. A coating's performance will be better if the wood is aged and has never been painted.
Moisture is a problem with wood.
Regardless of a floor's composition, the adage that time is money takes a slightly different twist when it's applied to painting floors. Instead of spending less time on the job, spend more. It'll cost a lot more to come back and do it again. If you get in a hurry because you think you may lose a couple of bucks, you'll end up losing a lot.