When wallcovering is being hung, why do the walls need to be prepped?
Any bumps or imperfections you feel or see should be repaired. It’s assumed that wallcovering will hide imperfections in the walls surface, but nail pops, paint runs, small bumps, dents, grit, etc. can sometimes show through the wallcovering, especially wide open patterns with light backgrounds such as white or beige. A shiny surface wallcovering is more likely to telegraph flaws. Roller marks or brush strokes in the paint surface may also show through some wallcoverings.
