You may find cracks in drywall tape on finished walls or on walls that have yet to be finished. To repair these cracks you will need special repair methods, materials, and tools.
Step 1 – Removing the Cracked Tape
Before removing the cracked tape, you'll need to remove the finish covering the tape. Use a scraper and scrape away the finish on the tape and even a bit beyond it. With your utility knife, cut through the cracked tape at the top and bottom edges of the tape, then pull the tape loose by inserting the edge of a putty knife or utility knife under the cracked tape and prying the tape away.
Step 2 – Applying New Tape
Use your taping knife to lay a thin coat of drywall compound on the drywall from where you removed the old strip of tape. Lay a new strip of tape over the joint where you removed the old strip. Apply more compound over the strip, once you have the strip in place.
Step 3 – Finishing
Allow your applied compound to dry. Even any ridges or raised areas by sanding. Clean off any compound dust or debris, then apply primer. When the primer is dry, apply paint that matches the surrounding surface.