I will soon be laying floor tiles in my kitchen, WHEN she decides which ones she wants. The thing is the floor (which is quarry tile and wont be taken up) is painted with what I think is Johnstones Bitumen paint. I say think because when we moved into the house we found half a dozen or so empty tins in the cellar and the also the first couple of courses of brick on the outside of the house are painted with the same paint I think. Can i just "prime " with PVA and tile as usual or is there something else I need to do first?