This tutorial will show you how to fix drywall tape that has lifted or cracked. Drywall tape can be damaged by movement in the wall, moisture or just by being installed badly. It will also lift if it is knocked by destructive kids or pets. Repairs are easy, but you will need to find the cause to stop it from happening again. If the lifted area is very small, you can just place a small amount of white glue behind the tape and push it back into place.
How to Fix the Lifted Tape
Cut away the loose tape and a foot or so beyond the damaged area. With a moderately coarse drywall sanding pad, sand the remaining compound but not all the way to the drywall paper. Vacuum away the dust.
A thin bed of joint compound can be laid over the drywall joint with a 5 inch taping knife. Make sure the compound is smooth and uniform in thickness and width. Be careful not to leave any large air pockets or gaps, and extend the compound at least 2 inches on each side of the joint.
Measure the missing tape section and cut a piece of new tape slightly shorter. Smooth the new tape into the compound with the taping knife, making sure there is no wrinkles or air under the tape.
Keeping the knife blade flat, apply a new, thin coat of joint compound over the tape, taking care not to move the tape’s position. Allow to dry overnight.
You can use fiberglass tape instead of paper tape. The fiberglass tape is self-adhesive so you can skip the first joint compound step.
A spackle that turns from pink to white as it dries can be useful if you have time constraints as you can immediately see when the compound in dry.
Using a medium sandpaper, or sponge, carefully sand any high spots. If the tape starts to show, stop sanding, this is the time for the next coat.
Use your taping knife to spread another thin layer of joint compound over the entire repair area.
Allow to dry thoroughly, then sand again using finer sand paper.
Use progressively finer sanding sheets until the compound is blended with the rest of the wall surface.
Vacuum any dust and paint the area. Use a primer before painting so the patch doesn’t show through.
If you have a textured wall, you should add the texture after the final coat of compound is dry. Some textures need to be sprayed on, others are applied with a taping knife and more mud.
WARNING: If you're concerned about getting drywall or joint compound dust into your body, then wear a face mask and safety glasses while sanding the area. If you choose to use an electric sander for the job, you'll definitely need to wear those.
How to Stop the Problem from Recurring
If your room is humid, you may need to install a de-humidifier to keep dampness at bay. If your room is always damp, there may be a leakage problem or bad house footing that will need to be fixed.
If your tape problems are caused by movement in the walls, you can keep repairing the lifting as it appears or a permanent fix is to take down all the drywall and refix with suitable clips that allow a little movement.