I own an older house (early 1900s), and It has as much as 5 layers of wall paper on the walls and the ceiling. There is about 1000sq. ft. of floor space, so I would like to avoid scraping all of the paper off. Also, the wallpaper has been painted over with several coats of paint, which makes it even more difficult to sc****. Lines from the overlaping wall paper are visible as well as some small cracks in the plaster. Could I lay drywall over the wallpaper and plaster, or is my only option to remove the wall paper?