[BrianinDC]

I live in a 10 story condo and have a nasty seam that keeps cracking and re-appearing. Hoping you guys can offer some advice.

The soffit contains the ductwork for the AC, so I'm guessing that the problem is related to the joint and the expansion from the heat.

A contractor who was in here working on my kitchen put some tape over it. It was some "new" great tape he said—it wasn't regular paper, but it wasn't mesh either. I imagine you guys know exactly what it was. Anyway, he said, "This'll get rid of your cracking problem for good."

Anyway, as you can see, it isn't working. This is after two coats of mud, and the crack has come back after less than two weeks.

Any advice? Fiberglass mesh? Something else altogether?

Thanks!

 

[mako1]

First off the contractor did a poor job.Does not even look like a crack but a very poor mud job.I would use some fiberfuse and and hot mud. (setting compound such as durabond)

 

[BrianinDC]

First off the contractor did a poor job.Does not even look like a crack but a very poor mud job.I would use some fiberfuse and and hot mud. (setting compound such as durabond)

Well, it's definitely a crack. I know this because it was lightly there when I moved in to the place in May, so I smacked some joint compound on it (not realizing how bad it actually was), then some 123, and then painted. And then the crack reappeared worse than before—which is what led me to ask the contractor about it when he was in.

Think the hot mud would do a better job of handing the expansion and contraction than the joint compound is?

 

[joecaption]

Just not a good practice to have any seam along side of an opening like that.
Picture over the top of a window or door opening, unless the seam is some place near the center of the opening it's likely to crack.
Did you add screws before mudding to make sure it was not moving?
100% sure it was even taped?

 

[BrianinDC]

Just not a good practice to have any seam along side of an opening like that.
Picture over the top of a window or door opening, unless the seam is some place near the center of the opening it's likely to crack.
Did you add screws before mudding to make sure it was not moving?
100% sure it was even taped?

Well, it's a 30 year old building. Lots of things in here that aren't good practice. :smile:

No, didn't add any screws. All 140 units in here have soffits like this one. I'm not sure why mine is cracking more than most. I am definitely sure that he put tape on though. Maybe I'll try a layer of the fiberglass mesh tape and feather it out super wide?

 

[GottaFixIt]

I'd be focusing on what joecaption said about screws. I had this problem in every room in my house (cracking plaster ceiling). No matter how many times it was coated, it would crack again - until I screwed everything back up tight. Haven't seen a crack since.

 

[ToolSeeker]

Most times, when it cracks something moved. When it keeps occurring almost always something is moving. In my opinion to just keep adding mud is not going to solve the problem.

All that old mud needs to be removed (sanded off) down to the bare drywall. Then push on both side of the crack to see what is moving. Add a few screws, then using a utility knife or the pointed end of an old bottle opener V out the crack. Then fill the crack with the hot mud, when dry use either Paper tape or Fibafuse (not Fibatape), this sounds like what he might have used to tape, then finish with regular mud. You could also use one of the vinyl tapes like strait flex from the box store. The hot mud plus these tapes will add a lot of strength to the joint.

 

[BrianinDC]

I'd be focusing on what joecaption said about screws. I had this problem in every room in my house (cracking plaster ceiling). No matter how many times it was coated, it would crack again - until I screwed everything back up tight. Haven't seen a crack since.

Most times, when it cracks something moved. When it keeps occurring almost always something is moving. In my opinion to just keep adding mud is not going to solve the problem.

Got it. What exactly is likely to be moving though? Is it the air itself moving the ductwork behind the drywall? If so, is that what probably needs to be screwed—in which case, aren't we talking about actually removing the sheetrock to get to it?

Here's one of the vents to give you an idea of what's behind it:

 

[ToolSeeker]

When the mud is removed you will be able to tell if this is a seam in the drywall if it is you could stop the movement by simply adding a couple screws. If the duct itself has movement then you will probably need to open it up and add some blocking. If it's just a stress crack (not a straight line like a seam would be) then just the hot mud and tape may hold it. But if this is the problem to do it correctly would be to add some blocking.

 

[GottaFixIt]

In my case, it wasn't a seam, but the entire plaster system had broke loose and sagged causing a crack.

I found & marked the joists & added screws every 16". I was surprised to see that it was actually drawing the ceiling up by around 1/2".

In your case, I'd be checking for lumber in that area and add some screws around the crack. If that doesn't fix it, I think you'll need to open it up to find the structural deficiency.