How to Repair Cracked Corners on Drywall

Every home settles unevenly as it ages. This sometime causes inside corners to crack or ripple. Often the crack will run from floor to ceiling. Once you spot this problem, watch it for two to three months for continued movement and fix it after all movement stops.

The key to renewing the strength of the corner is to remove all loose tape and drywall compound. If the drywall below has crumbled, cut it away with your utility knife and fill the gap with setting compound.

Re-tape the joint. Crease the paper tape down the middle so if fits into the corner easily. 

It's difficult to spread compound smoothly on one side of the corner without marrying the other side. The trick is to apply compound for the second and third coats only on one side at a time. Let the one side dry, then do the other side.

Finally, buy a fine-grit sanding sponge to smooth the corners. It will do a nice job without gouging.

1. Cut through the tape at the end of the cracked area and slice, scrape and tear away all loose tape and compound.

2. Apply a 1/8-in layer of joint compound, then fold and press paper tape into it. Stroke the length of the tape, squeezing compound out on both sides. Let dry.

3. Apply second and third coats to smooth the joint, tapering the compound about 6 in. out. Let one side dry before applying compound to the other side.

4. Lightly sand the finished repair using a fine-grit sanding sponge to make a crisp corner. Prime and paint to match the existing wall.