Hi, I've recently started remodling my bathroom in my 1970's slab-prefab house. I've pulled up most of the old plastic like tile and some of the coating at the bottom came up too but now I am left with what I think is the cut-back asphalt adhesive. How on Pete's name do I get rid of it? Its a buger to scrape off with a razor blade and its too givable for a hammer and chisel. Thanks