How to remove old wallpaper?


You should strip the wallpaper if you have a previously papered surface. It may even be indispensable, which depends on what kind of wallpaper you currently have and how you want to refinish the walls.
However, you may decide not to remove existing wallpaper under some conditions. When it is free of bubbles, buckles and wrinkles, you can safely paper over a single layer of smooth, well-adhered wallpaper. You will need to do some prep work, including re-pasting any loose paper, patching as necessary, cleaning the walls and applying a special primer.
You should not install over existing paper under the following conditions. 
1.You suspect there may be more than a single layer of wallpaper on the surface.
2.The existing wallpaper has a vinyl, foil or plastic film. Even if there is only one layer in good condition, the wallpaper should be removed. Because wallpaper adhesive will not adhere well to these surfaces.
3.You have the plan to hang vinyl wallpaper. The glue between the two papers will not dry well if the previous wallpaper is also vinyl. The glue under it may get wet and start to mildew if the old wallpaper is not vinyl.
4.The existing wallpaper is grass cloth, burlap or cork.
5. When running your hand over the surface of the wall, you can hear crinkling sounds. If you do, the wallpaper has buckled and it needs to be removed.
6.You must remove the wallpaper, if you are planning to paint. Paint will seal the surface and make the wallpaper almost impossible to remove in the future. What’s more, the painted surface will not look as smooth as it could and your efforts will be wasted.