It's always best to remove prior paint coatings from your floor before applying a new ArmorGarage Epoxy Coating. Most times if the prior coating was a Home Center type of coating most of it should come off rather easily, this product will remove those areas of paint that resist removal by pressure washing and etching.
This proffesional heavy duty paint is designed to remove most paints, varnishes, laquers, etc from the toughest and oldest concrete floors. Even removes most dried 2-part epoxies. Solvent based, industrial grade. Simply apply, let stand for about 10 minutes, and brush with provided stiff bristle brush (use your mop or broom handle) and rinse. Coverage varies from 50-150 sq ft/gal depending on surface, thickness of paint to be removed, etc. For stubborn areas repeat a second application and use floor scraper to aid in removal of paint from floor.