How to Patch-Up Cracks After Joint Compound Application

If you've recently use joint compound to close a gap in a drywall application or repair a crack, you may be dealing with cracking of the patched area. The cracks can be anything from a large crack to spider web like cracks.

Step 1: Drying

Be sure the patched area is totally dry before you begin any patching job other than digging all of the compound out and starting over. This is necessary because it may crack more as it continues to dry. Also, don't dry patched areas too quickly with a fan, heat gun or blow dryer because it can cause more cracks.

Step 2: Choose a Method

There are a few ways to repair cracks in new joint compound. If the cracks are really big you may want to start over with the repair. Dig out all of the compound first. Then apply fiberglass compound tape to the area and spread joint compound over it. This will most likely prevent new cracks.

Another method is to mix drywall compound to a bit thinner consistency than the ready mixed variety and apply it over the cracks. This thinner mixture doesn't crack as easily and will fill in both small and hairline cracks.