Had a mud cracking issue that took 5 hours to figure out

I was doing a ceiling patch in a bathroom and the mud kept cracking overnight. Turned out the old drywall was still sucking moisture because I didn't prime the edges first. Has anyone else run into this on old reno jobs?

3 comments

3 Comments

david_reed2210d ago

Did you use any kind of sealer on the old edges like Gardz or just a standard PVA primer? I've had mixed results with standard primer on those real thirsty old drywall patches where the paper is half peeling. Wondering if that specific product made the difference for you, or if you just threw on a coat of whatever you had laying around.

the_alex10d ago

Man I used to think priming before mudding was overkill, but this exact thing happened to me on a bathroom ceiling too. The fresh mud just cracked overnight and I was scratching my head until I realized the old paper was sucking up all the water. Now I always hit the edges with a quick coat of primer, even if it feels like a waste of time.

singh.harper10d ago

Twenty years of owning old houses taught me the same thing. I've got a 1920s bungalow where every wall has at least three layers of paint and paper, and @the_alex is right, it's exactly like trying to stick tape to a dusty ceiling. The primer seals off that thirsty old surface so the mud can actually bond instead of getting sucked dry. People skip it thinking they're saving time, but you end up spending twice as long fixing cracks anyway.