Repairing Cracked Ceilling Vaults

d's

Hey crew,

I've been called in to this fancy sushi restaurant that's doing an overhaul in 1 week.

The original drywaller used a flexible plastic bead in the offangles of the vault that cracked all to **** and he had to warranty them(product was also recalled apparently although that could have just been his excuse). The owners now want me to repair the whole setup during the shut down.

So... tonight I ripped it all out and got into it. Rafters are on 24" centers, so the sheets we're double re-screwed 1inch away from the centre, The joint is still quite raised because of the original bead so scraped back existing mud to improve the bond. Planning on prefilling, meshing, and floating the joint out back to a flat angle with confill to give it extra strength and then will recover with no-coat 450 flex bead and finish.

Any thoughts on my repair strategy?

D's

WorkhorseTom

Have you considered the fact that maybe the trusses are deflecting or sagging? If you trace the ceiling down to vertical non exterior load bearing walls within the cathedral are there signs of compression?

d's

As far as i know the original structure is probably 40 years old - a new truss roof was added probably 4 years ago. the roof has a low angle probably 3/12 or less. the joints have cracked at the peak, interior non load bearing partition walls, and exterior load bearing walls.

Is this a sign of compression, or of a crappy bead install? I don't know. I'm assuming that since the roof is new that it was engineered properly(snow load is huge here.) What could be done about compression/deflection if that were the problem?

D's

genecarp

Sounds like it could be movement causing the problem. between the 3/12 pitch, the 24'' centers, and the snowloads you mentioned, it does not sound good. throw a level on the exterior walls, (eve ends). get back to us. solution if movement is cause, COLLAR TIES, G


One more thing, never assume it was done right, with all the a=holes in our business, its more likely it was done wrong. DO I SOUND NEGATIVE ?

__________________

WorkhorseTom

Sell him on a low profile cosmetic beam, My money says it wasn't the finisher. Odds are it was designed right and built wrong.
P.s. Had this very experience in a engineered truss home with a 57' scissor span. 2cents

Tradesman

This is a situation that occurs frequently with trusses. It is known as truss uplift, and if you Google "truss uplift" you'll find some articles that explain what is going on. It is a recurring problem due to seasonal changes in the lumber. It is not due to bad framing or bad drywall; wood moves and the drywall must be able to handle that movement somehow.

Best fix is to use Strait-flex X-Crack on the framing and attach the drywall to it. However, if the original drywall is not coming out, the next best option is to use Trim-Tex's Magic Corner, a vinyl bead consisting of two flanges connected by a rubber hinge. The hinge allows the adjacent pieces of drywall to move independently of each other and accomodate the expansion and contraction of the framing.

The other option, as already suggested, is to cover up the joints with some sort of trim, false beam, etc. However, if this is fastened to both sides of the joint, then caulked and painted to blend in better, it too will crack over time as the framing moves.

Frankawitz

WOW a 3/12 pitch and 24 oc" that's asking for problems. with the dead load of snow has to be kickin the trusses butt. you would think the builder would have set them at 16 oc" with that pitch just to carry the snow load.

d's

I repaired as planned minus the mesh. The trim-tex product would have been well suited but wasn't available and the clock was ticking. I explained to the owner that I would not be able to warranty the work and he understood. This will definitely be a test of the no-coat product - should have results after the winter.

D's

Tim0282

You can probably put your money on it that the crack will be back. Too much truss deflection with the low pitch. It is awfully easy to blame the drywaller for a crack. Sure hope it works, though.

Lionheart27

I guess it can be related to the fact they use 2x6 as minimums for rafters these days.

Use paper tape not fiber on corners!!!!!!!!!!!!!!!!!!

kgphoto

You should have gone the X-Crack route. I have heard some attorneys argue that you can't waive liability. Do what you know is best or you may still be on the hook for it. Of course, this is California.

d's

Agreed the X-Crack would have been the safest way to go however the owner needed to be re-open for business in seven days so he was happy just to have it fixed.

How does the x-crack work in a retrofit situation anyways- I'm assuming I would have had to remove the board 12" from the peak, installed the x-crack, reinstalled the board, and floated the whole thing out 18" both sides. Correct?

D'S

Aaron111

I would use that good bead also....float it well so you ne need sand and then paint lol