Sheet rock under ridge beam has developed cracks 9

[Richie-Rich]

Hello, hope you guys had a great thanksgiving. About two years ago, I built a portion of our house with vaulted ceiling etc.. I am seeing cracks in the sheet rock (gypsum board) under the ridge beam. The foundation is about 20 - 12 ft deep piers (16 in diameter, and about 6 ft apart) with 24 inch wide grade beam on these piers. I am not seeing any noticeable cracks anywhere else - either the inside or outside walls. Attached is the picture:

I did contact the structural engineer who designed this and he does not think it is the crack in ridge beam, some issue with the gypsum board.

What do you guys think?

I think there is no insulation between the ridge beam and the gypsum board, is it because the contractor did not put insulation between the ridge beam and sheet rock, and the ridge beam (parallam brand) had different amount (or size) of contraction and expansion (in day (60-80F) vs night (30-50F) time) than gypsum board that this happened because of that differential? Or do you guys think I really should get this investigated instead of just patching the crack up and repainting it?

Thanks for your time!

 

[Tomfh]

You can’t conclude much based on that photo, however the photo is consistent with non-structural cracking of ceiling trim, that you will find in 50% of houses.

 

[JoshPlumSE]

What do you guys think?

Yup, gyp board likes to crack like that. It might not have been taped / finished very well. That would be my guess.

Dry wall like this is much more brittle than the wood beam. Much more sensitive to changes in moisture or such. Maybe you went through a real hot spell, cold spell or dry spell where there was some differential expansion or contraction that caused this.

Honestly, even when you do just about everything right, dry wall can still crack. But, it is rarely something to get excited about.

 

[phamENG]

What kind of span are we talking? Engineered wood products typically have limited creep deflection compared to sawn lumber, but it does happen.

 

[Richie-Rich]

@phamENG, I am not sure how wide the beam is (end-end beam should be about 35 ft - I also know that there are more than one beam that was used for the entire span), but the crack is invariably along the entire span of the room, which is about 13 ft wide. Also, I do not see any visible sagging of the beam as well. This room has a lot of sunshine and gets warm by afternoon, and in winter the temperature can drop to low-high 30F.

 

[jayrod12]

I bet this guidance was not followed when the drywall was attached. Therefore the cracks show up because the movement cannot be accommodated.

 

[Tomfh]

Is it definitely wrapped in drywall?

It looks like it could be corner beads along the beam, which someone has simply painted.

 

[JoelTXCive]

That looks like normal sheet rock cracking to me. The sheetrock is cracked right at the corner bead.

On a vaulted ceiling like that, you could have all sorts of factors that cause the crack....humidity, temperature change, etc. How far above the beam is the roofline? Are you in an area where the roof gets extremely hot or cold?

I would patch & paint; then then monitor the crack to see if it shows up again.

If you have some real structural settlement or movement going on; then you will most likely see secondary effects and cracking in other locations.

 

[dik]

@Jayrod... I've used a similar detail for the odd house I've done, but at the re-entrant corners at the top, I've provided a break using 'J' molding instead of corner beads to provide an actual joint. The fastener is at the top and not the middle.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[Canuck65]

35 feet is a big span and it would have to be a very stiff beam to limit deflection.

A lot of contractors would have covered the beam in wood trim rather than drywall, and then the cracks would not show.

 

[Richie-Rich]

@TomFH
"Is it definitely wrapped in drywall?

It looks like it could be corner beads along the beam, which someone has simply painted."

I have the contractor who build this new addition coming tomorrow to take a look at this. I will ask him and update here.

@JoelTXCive
"How far above the beam is the roofline? "

I think the roof ridge sits right at top of this ridge beam. I am attaching a picture - I remember contractor having to put the ridges on the roof because city inspector wanted it to be redone this way (I can find out more and update tomorrow). I am in Bay Area, CA - so not too hot or cold.

@JoelTXCive
"If you have some real structural settlement or movement going on; then you will most likely see secondary effects and cracking in other locations.

I mentioned in my OP that the foundation is piers with grade beam (not the shallow foundation), that should not cause any settlement correct?

 

[JoelTXCive]

Generally speaking, the piers and grade beam would be more stable than a shallow foundation. (at least in Texas with our clay soils)

I think it is unlikely that a foundation problem would manifest itself first all the way up at the roof line. If the foundation elements are moving enough to cause a crack; then I think you would see cracks lower down first in wall corners; and/or around doors + windows. The cracks would start lower and work their way upwards; and not start high up and work their way down.