Again, I'm trying to skip the process of knocking out all the black stuff left when you remove tile. I've spent hours with a hammer and chissel and it seems I'm getting no where so....., I was thinking maybe I could lay down plywood over the whole thing and then lay hardwood flooring over that. It's the glue down type. Come to think of it, if it's made to glue, can it also be used to nail? Maybe I could put a leveler down before the plywood?