Please help! We have bought a 100 year old house and want to tile our kitchen floor with porcelain tiles. After reading a few things on the site about uneven floors, concrete floors, bitumen etc, we looked at ours and thought it had Marley tiles, but it's not. We blow torched a small area and discovered it's bitumen. It was around half to one inch thick, with a fibreglass membrane. We have broke it up and lifted it all, to reveal Red Quarry tiles. What should we do now? Can you tile over Quarry tiles? Have we done the wrong thing taking up the uneven bitumen floor? Do we need to lay new concrete floor? Any advice would be really helpful as we are novices and maybe shouldn't have started and left it to the experts!!!!!!