# Crack at Peak in vaulted Ceiling



## Milhaus

Hi - I've been trying to determine the root cause of a ceiling crack for a customer. When the customer first called, they said there had been a crack in their vaulted ceiling, at the peak, almost since it was built 20 yrs ago. There were some other cracks on interior walls where the ceiling met the walls as well.

I went in and repaired it, assuming that using StraitFlex would take care of the peak, and that over the years the remainder of the cracks were due to settling, etc., because there were some issues with settling in the basement. I researched truss uplift, but was not sold that this was it. 

Well, the work has been completed for 3 months, and now there is a crack on the ceiling that runs parellel to the peak, but not along the tape seam (it is about an inch below the edge of the tape). It appears that the sheetrock itself 'cracked' due to the tension near the interior wall. There are some hairline cracks that have appeared on the tape joint where the vaulted ceiling meets the interior wall. I haven't been in the attic to determine exactly how the addition was framed, but that I think should be my next move. I will verify framing if possible, what type of inso, etc. so we know exactly how the room was built before proceeding. 

There are no cracks along the exterior walls. My assumption is that it is stick framed, but it could be a scissor truss. I can't figure out why the sheetrock would crack as it did. We have had some extremely hot days in the last month, and with the vault, I would think that humidity and the heat are wreaking havoc on the framing. Cold interior and extremely hot exterior - is it possible that even stick framed , ie 2x10 or 2x12, would see similar expansion issues as in truss uplift?

Anyone else seen this? I've researched truss uplift, but don't know for sure if that is what we are seeing. 

Thanks in advance for any advice.


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## Tinstaafl

I've seen the tape pull loose at the ridge of cathedral ceilings many times, but never saw the drywall crack a bit lower down as you describe.

Usually, what causes it is that the rock was screwed very close to the intersecting edges, instead of a few inches back. The latter allows the drywall to "float" and flex a bit as the framing moves (which it always does for the life of the house).

I've never come up with a truly lasting fix that didn't require a fair amount of surgery.


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## mski

Truss uplift was what I was thinking when I first started reading your post but you squashed that by then end of paragraph 2.
Usually when cracking occurs at the wall/ceiling that can be contributed to seasonal truss uplift.
When cracking occurs at the peak after the first year or so you can figure the rafters/trusses acclimating.
Since you repaired it 3 months ago at the start of summer can it be a humidity thing?
Like the owners opening the windows in the evening then air conditioning it during the day?

The crack there now, can that be the spackle cracking at the edge of the tape and not the drywall cracking?


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## griz

Expansion/contraction & we try to build rigid structures on a planet that is moving & spinning....

Your situation is sorta like guaranteeing concrete not to crack...:whistling


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## mudpad

griz said:


> Expansion/contraction & we try to build rigid structures on a planet that is moving & spinning....
> 
> Your situation is sorta like guaranteeing concrete not to crack...:whistling


Right. I have this situation in my own house. I actually made a small (about 12" wide) flat spot at the top of the vault and used flex bead tape on each side. 18 years ago. Both sides cracked within a year and flex bead actually came loose and was hanging in spots. Just had it fixed for the third time (first two by me) 3 months in, so far so good.:thumbup:


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## Tinstaafl

mudpad said:


> I actually made a small (about 12" wide) flat spot at the top of the vault and used flex bead tape on each side.


For some time now, when I have the chance I lobby vociferously for placing an oak (or whatever) plank in that location in order to sidestep the whole issue. :thumbsup:


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## griz

Tinstaafl said:


> For some time now, when I have the chance I lobby vociferously for placing an oak (or whatever) plank in that location in order to sidestep the whole issue. :thumbsup:


I prefer something that looks like a beam...:thumbsup:

but it's the same idea....

Great minds....:whistling:laughing::laughing::laughing:


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## Milhaus

Thanks for the comments. I was leaning towards the same fix my self. Some sort of trim cover. But then I got to thinking about air sealing. Similar to adding crown to a truss uplift crack - there is still a crack that air is continually moving through so you're efficiency takes the loss. Maybe there is a compromise that you must be willing to take with cathedrals. There are already faux beams running parallel to the peak, down about 3 ft. I suppose I could add a painted 1x6 to the peak, mitered to meet the ceiling, and then caulk the edges before final paint coat. Shy of taking out 18" or so on either side of the peak, and using some modified drywall clips to let it float, ie surgery - this may be the only way to address it. 

I'd rather do surgery. Thanks again!


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## Sir Mixalot

Milhaus said:


> Shy of taking out 18" or so on either side of the peak, and using some modified drywall clips to let it float, ie surgery - this may be the only way to address it.
> 
> I'd rather do surgery. Thanks again!


Or you could cut it out 18" on both sides, then pop a line and score the center back only of a new piece of drywall and put that up with no seam at the vault, just your own a factory crease. :thumbsup:


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## blacktop

mudpad said:


> Right. I have this situation in my own house. I actually made a small (about 12" wide) flat spot at the top of the vault and used flex bead tape on each side. 18 years ago. Both sides cracked within a year and flex bead actually came loose and was hanging in spots. Just had it fixed for the third time (first two by me) 3 months in, so far so good.:thumbup:





Milhaus said:


> Thanks for the comments. I was leaning towards the same fix my self. Some sort of trim cover. But then I got to thinking about air sealing. Similar to adding crown to a truss uplift crack - there is still a crack that air is continually moving through so you're efficiency takes the loss. Maybe there is a compromise that you must be willing to take with cathedrals. There are already faux beams running parallel to the peak, down about 3 ft. I suppose I could add a painted 1x6 to the peak, mitered to meet the ceiling, and then caulk the edges before final paint coat. Shy of taking out 18" or so on either side of the peak, and using some modified drywall clips to let it float, ie surgery - this may be the only way to address it.
> 
> I'd rather do surgery. Thanks again!


http://www.all-wall.com/Categories/...lex-450.html?gclid=CNPmmrv_wLkCFaYDOgodFxIA6A


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## kgphoto

If you go the surgery route, try and find some X-Crack by straitflex. It is a backing that isolates the drywall from the framing. Then you can use something like straitflex or no coat to get a nice crisp and straight line on the seam.


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## ToolNut

Trim tex makes a product called Magic Corner that seems like it would work in a situation like this. It has a small flexible center that allows for some movement. Have never used it for this but have used it in some mobile homes where cracks kept recurring. Would like some opinions I have a crack in a peak to repair also.


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## Sir Mixalot

I do know the paper tape with metal doesn't work to well. :no:


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## Golden view

All my vaulted ceilings built properly didn't crack. 140 degree temp difference summer to winter. 55 psf ground snow load. Just ultra flex. But my drywall contractor said he had success on problem houses carving about a 1/4x1/4 channel at the peak and filling with elastomeric caulk. I'm not sure of the actual technique of carving this channel.


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## ToolNut

Golden view said:


> All my vaulted ceilings built properly didn't crack. 140 degree temp difference summer to winter. 55 psf ground snow load. Just ultra flex. But my drywall contractor said he had success on problem houses carving about a 1/4x1/4 channel at the peak and filling with elastomeric caulk. I'm not sure of the actual technique of carving this channel.


Maybe I'm looking at it wrong but isn't that what magic corner is without the cutting. I was really hoping someone would look at it as I have one of these to repair. Am on laptop don't know how to link to trim tex. Maybe later on the big computer.


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## blacktop

Sir Mixalot said:


> I do know the paper tape with metal doesn't work to well. :no:


They put that on a seam?:blink:


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## blacktop

ToolNut said:


> Trim tex makes a product called Magic Corner that seems like it would work in a situation like this. It has a small flexible center that allows for some movement. Have never used it for this but have used it in some mobile homes where cracks kept recurring. Would like some opinions I have a crack in a peak to repair also.


I've used the Magic corner in a few attic renos . It has a nice look but it's a bit of work compared to ultra flex, Trim tex may not like me saying this but I taped the flange [paper] for insurance.. It's much cheaper than U/F ,But I still prefer the U/F 450 for those [off] off angles ...The 450 can straighten out a mess after a little pre-fill .


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## ToolNut

Thanks blacktop since this cracking is so common on these ceilings I thought this might eliminate the problem. Maybe it's just here in Fl but almost every cath. ceiling has cracks. I thought that little piece of flex would absorb the movement.


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## Big Shoe

There is a you tube video with Myron Fergeson installing Magic Corner.

Maybe one of you smart guys can post it ? :nerd:

I'll have to learn how to do that one of these days. :whistling


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## Sir Mixalot

:thumbsup:


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