I need to know what I need to do to apply texture to walls in a manufactured home. The majority of the home was built with textured walls, but (3) bedrooms have the typical type walls that you see in a manufactured home. It's kind of like paneling with a wallpaper type look to it. There are floor to ceiling seems every three or so feet. Do I need to hang drywall over the existing walls, or can I apply something prior to texturing?