Can you use polyurethane over painted concrete?

Yes, you can use polyurethane over painted concrete, but it's essential to ensure that the paint is fully cured and adheres well to the surface. Before applying polyurethane, clean the painted surface to remove any dust or debris, and consider using a primer designed for concrete to enhance adhesion. Choose a suitable polyurethane product that is compatible with both the paint and concrete. Testing a small area first is always recommended to check for any adverse reactions.