Question: I am planning on wallpapering the master bedroom in my home. I have applied wallpaper in the past, and have had numerous problems aligning the wallpaper in the corners of the room. In some cases, after the wallpaper has dried, the corner seam separates and you can see the painted wall behind it. I have also had problems with creases appearing in the wallpaper just as it goes around the corner of the wall. What is the best method to hang wallpaper on the inside corners of a room?
Answer: Hanging wallpaper on inside or outside corners is one of the most complex parts of hanging wallpaper.
If walls were plumb and flat, there wouldn’t be a problem, but as most walls in a home use drywall, with mudd and tape to complete the project, the walls are not actually flat and this is highlighted in the corners. Hence when you try to wrap the wallpaper around the corners, the distance that the wallpaper has to travel at the top of the corner is less than it must travel at the middle or bottom of the wall. This causes the wallpaper to crease or wrinkle as it comes around the corner.
The overlap method hides any creases or wrinkles and prevents the wall from appearing when the wallpaper dries and shrinks.