Q:
About a month after I finished some drywall repairs to a wall and ceiling, several ridges appeared along the seams. They’re about 1/4 in. wide and 1/4 in. high, and they range in length from 4 in. to 18 in. Mudding and taping were unremarkable. What happened?
Walt Dadik, Weston, CT
A:
Myron R. Ferguson, aka “That Drywall Guy,” replies: It could be one of several things. Most likely, these ridges are the result of some building movement in combination with an inadequate connection between the drywall and framing. The edge of the drywall may have barely caught the framing and as a result wasn’t attached securely.
Drywall seams near a load-bearing header or on a high wall such as in a stairwell also are subject to ridging or cracking. Sometimes there isn’t enough joint compound behind the tape, or the tape was not pressed firmly enough into the compound as it was applied. Or there could have been a large gap filled with joint compound that didn’t have a chance to dry thoroughly before it was painted.
To repair these areas, you’ll have to dig in: Remove any loose tape, and make sure the edges of the drywall are fastened to the framing securely. Refasten the drywall if necessary. Then you’ll have to retape the areas, feather out the new drywall compound, prime, and repaint the repair.
