So I just bought a house a few weeks ago and painted everything now it's time for the bathroom. When I started to tear the paper off instead of getting paper. I got the paper plus the backing of drywall so now I see cardboard. Should I paste the wall with joint compound to have something to paint on or should I put primer over the cardboard. The house was build in 1985. The bathroom was never painted before so when the glued the paper on it stuck very good. Does anyone have any idea of how or what I should do to make it look nice!!