I've heard that a 4000 psi pressure washer will take off most paint. I have a patio painted with latex paint which I'm going to try this on. If it is epoxy, and most concrete paints are, you have a problem and will probably have to use a paint remover. If you are going to do this in the basement you need good drainage, these things produce about 3 to 5 gpm of water. I tried acid on my patio and a low pressure (1100 psi) washer and it removed about 10% of the paint. Acid in the basement would be dangerous. Paint removers can also be dangerous.