1. Popping wallpaper bubbles
An air bubble underneath the surface is a common wall covering problem. The solution is simple, but you’ll need a glue injector. There are two types of injectors, both of which work well. One looks like a syringe, and the other has an accordion bulb above the needle. You should be able to find them at a wallpaper or home-improvement store. Here’s how to get rid of that bubble: Using a sharp utility knife, cut a small slit in the paper along one side of the bubble. Insert the injector’s needle into the slit, and squeeze seam adhesive under the bubble. Press out excess adhesive and wipe it off with a damp sponge. Roll gently with a wallpaper seam roller to flatten the bubble.
2. Fixing curled seams
Your wall covering’s edge has curled up at the seam—no big deal; it’s easy to fix. Here’s what to do. First, moisten the area with warm water to make the material pliable. Lift the edge carefully and slip seam adhesive under the edge using a strip of index card or a toothpick. (If the paper is solid vinyl, use vinyl-to-vinyl adhesive.) Flatten the seam gently with a wallpaper seam roller and wipe away excess glue.
3. Regluing peeling borders
Wallpaper borders, which are often used across the top of walls or at chair rail height, are notorious for peeling at the edges. If this happens, just dab white glue on the wall and on the underside of the border with an artist’s brush. Roll the edge gently with a wallpaper seam roller.
4. Painting or repapering over existing wallpaper
If it’s untextured, solidly attached to the wall, and only one layer thick, you can paint or repaper directly over old wall covering. To make sure the paper is solidly attached, run your fingers over the wall. If you hear a crackling sound, the paper is loose. Putting paint or wallpaper paste over it will only make it more likely to come off. Check the seams and corners by trying to pry them up. If the paper adheres tightly to the wall, you’re in luck. To paper again, just apply the new covering over the old. To paint, first prime the paper with alkyd (oil) paint. (The water in latex paint could dissolve the wallpaper glue.)