I intend to use the wickes onecoat on a wall where i have removed some old tiles and they have some really hard to remove adhesive. so to smooth off ready for new set of tiles going to use onecoat and tile directly on to it after a few days when dry. dont want tbond/brown then skim . not enough time and more work. been told and read wickes onecoat is good stuff, 1. is onecoat going to be ok for this application? 2. should I pva before tiling?