Before wallpapering the ceiling, make sure it is clean. Apply a special primer specifically made to work with wallpaper. It is designed to reduce the amount of glue damage should the wallpaper ever be removed. Use a standard paint roller to apply the primer.
Determine your vertical start line for the first strip of wallpaper. This is done by measuring the width of the wallpaper then using that measurement to determine the placement of your starting point (usually from a corner). You can use a level, yardstick or a plumb line tool to make the vertical start line.
Measure the distance from one side of the ceiling to the other. Use that measurement to determine the length of wallpaper you’ll need. Add an extra four inches to this measurement so you can match up the wallpaper’s repeating pattern.
Pour the wallpaper glue into a paint tray or a paint pail. Use a 3-inch paintbrush to apply the glue to the back of the wallpaper. Bend down and look across the wallpaper from different angles to see if you’ve missed any spots.
Once the glue is evenly applied to the back of the wallpaper, immediately begin to “book” the wallpaper by folding the glued side in half over itself. Once folded, let the wallpaper sit for about 5 minutes to let the glue set.
Using a ladder or better yet, scaffolding (can be rented at a home improvement store or rental store), begin applying the wallpaper along the vertical start line. This is a two person job. One person will place the wallpaper along the vertical start line while the other person holds the wallpaper waiting to be hung, either by hand if on scaffolding, or with a dry mop from the ground.
As you hang the paper, you may notice some bubbles showing through. Using a damp slightly soapy sponge, run the sponge along the wallpaper to push the bubbles out and smooth the paper. The sponge also serves to clean excess glue off the wallpaper. Continue to sponge the wallpaper as you hang it.