Reattaching loose wallpaper seams and edges can prevent further damage: torn wallpaper. To fix loose seams or curling edges on wallpaper, you'll need a knife or craft stick, a damp sponge, a tube of seam adhesive with a pointed nozzle, and a wallpaper roller.
Loose seams and curled edges occur when too much adhesive seeps out when you roll wallpaper edges and seams. With pre-pasted wallcoverings, the factory-applied adhesive didn’t stick well to the product. Either way, the bond weakens, and eventually the edges and seams lift or curl.
Lightly dampen the loose edge or seam.
This step softens the adhesive.
Lift the loose edge.
Raise the lifted edge with a knife.
Place the pointed nozzle of the seam adhesive under the loose edge, seam, or tear and squeeze enough adhesive to coat the torn area.
Don’t apply so much that it get drippy.
Let the adhesive dry for 15 minutes. Some new products dry solid within a few minutes, so be sure to follow the manufacturer’s directions.
Roll the seam or edge with the roller.
Don’t press down too hard, because you’ll take out too much of the glue and the edge will lift again. Also, if you have embossed or textured wallcovering, pressing down too hard will flatten the design.
Wipe off excess adhesive with a damp sponge. If allowed to dry, the excess adhesive will dry with a noticeably shiny finish.