 You can put it on top. If the old flooring comes up easily, I always like to take as much of that up as I can. I don't like putting layers down. But you know what? If it's solid and it's flat and it's well adhered, then I think it's okay to go on top of it. Just keep in mind that when you do that, you make the floor thicker than it was before or taller than it was before. And sometimes, not so much just with vinyl, but sometimes like if you have a dishwasher, if this is a kitchen and you have a dishwasher,