A ceiling seam split on me in a Denver condo last month

I was taping a bedroom ceiling with a 12 foot lift, and the joint compound was still a bit wet. The next morning, a 4 foot section of the seam had a clean crack right down the middle. I had to cut out the bad tape, let the area dry for a full day, and re-tape with a slower setting mud. It added a day to the job, but the patch held. What's your go-to fix for a seam that cracks before it's even sanded?

3 comments

3 Comments

the_drew2mo ago

Let it dry completely before you do anything else. Trying to fix a wet crack just makes a bigger mess later on. Once it's bone dry, cut out the bad tape and start over with a better drying mud.

king.aaron2mo ago

Oh man, that's the absolute truth. I was reading this old forum post from a drywall pro last week, and he said the exact same thing as @the_drew. He explained that wet mud shrinks as it dries, so if you try to patch over a damp crack, it'll just pull apart again and leave you with an even wider gap to fix. His rule was to wait overnight, no matter what, then use a knife to scrape out any loose stuff before re-taping. Trying to rush it always ends in more sanding later.

emery_craig1mo ago

Last time I tried to skip the overnight wait was a nightmare. I patched a bathroom ceiling crack around 8 PM, and by morning it had pulled apart so bad I had to cut out a 3 foot section of tape and start fresh. @king.aaron nailed it about the scraping step too - one time I didn't scrape loose stuff and the new mud just peeled off in a sheet. Now I always hit it with a 4 inch knife and a shop vac before I even mix the mud. What's your go-to drying time for bigger patches?