Ridge Beam Structural issue? 5

[amorphous12]

Hello,

Apologies if this is the wrong forum, but I thought someone here might be able to provide an opinion. Looking at a home and underneath the ridge beam I've noticed a slightly jagged horizontal crack a little longer than the width of the ridge beam (photo attached - listing photo was photo shopped so I'm unable to show the actual crack). It is probably less than a quarter inch thick. The inspector mentioned this was probably just settling since this is where 50% of the load is supported, but I'm wondering if anyone thinks this is a larger concern?

 

[amorphous12]

Hi All, I was able to get a picture that shows the crack. Let me know what you think.

 

[radiocontrolhead]

oldestguy,

To address your previous post, the subject ridge beam in my opinion is structural and doesn't appear to have any tension ties at the "eve level." If there are no tension ties, whats resists the horizontal thrust but a structural ridge beam?

I believe the structural ridge beam is supported by a king post at the subject wall which is then supported by a header beam and finally somehow carried to foundation. Also, If the subject "ridge beam" was not structural, a simple 2x or 4x member could have been provided and the soffit removed entirely.

 

[oldestguy]

XR250: I have just the solution for you and your client. Some time ago my step daughter needed a big garage, roughly 30 x60'. She hired some local Amish guys who came via a hired local"Englishman" (That's anyone not Amish). The garage was a form of pole building, but the poles were anchored to a slab. Roof and siding to be sheet metal. They had it all done when I stopped by to pay the bill for her. Job was to have bat type insulation laid on the rafters and then the sheet metal screwed down. In jig time those Amish had the roof off, insulation placed and sheets back on in about a morning. I'll bet they are pretty good at pulling nails too. By the way their swearing is done in German I think.

 

[charliealphabravo]

It looks like material shrinkage to me, but the crack location is where you might expect for compression load under the ridge beam.

It is not uncommon to see some distress at these types of locations (at bearing under long spans). The beam can be expected to rotate at the bearing and in most residential construction there are no provisions such as movement joints in the drywall to accommodate this.

 

[msquared48]

In looking at the last picture it seems like a horizontal crack occurred at a sheet rock seam line.

Again, just patch, paint, and monitor.

May not have occurred if there was no sheet rock seam.

Mike McCann, PE, SE (WA)

 

[NorthCivil]

I've opened up many many old hand framed wood roofs from the 1880's to the 1950's on the west coast. The biggest ridge I've ever seen was a 2x8, the smallest, a 1x4 (with a 1x4 being much more common). If the roof has a good pitch on it, ridge beams don't really go into bending. That said, I always design for a fully loaded structural ridge beam.

These things are held together more by their diaghrams than we like to think.

my vote is on some sort of swell/shrink issue.

 

[XR250]

XR250: I have just the solution for you and your client. Some time ago my step daughter needed a big garage, roughly 30 x60'. She hired some local Amish guys who came via a hired local"Englishman" (That's anyone not Amish). The garage was a form of pole building, but the poles were anchored to a slab. Roof and siding to be sheet metal. They had it all done when I stopped by to pay the bill for her. Job was to have bat type insulation laid on the rafters and then the sheet metal screwed down. In jig time those Amish had the roof off, insulation placed and sheets back on in about a morning. I'll bet they are pretty good at pulling nails too. By the way their swearing is done in German I think.

Sounds like the folks I need. Send me their contact info!

 

[oldestguy]

Frankly, a solution for this fix seems pretty difficult to me. We know which way things have to warp back to where they started from, but bent nails take a set or are harder to bend back. Cables stretch, a failed support could result in loss of a leg or two. Jacks need a solid place to take the push, etc. This would make an interesting separate post and might even result in a patented system for these failure fixes. Just imagine an owner having to live with a tie rod and turnbuckle under the ceiling of his living room, there forever. Not one maybe five.

 

[BridgeSmith]

Given where the crack goes, I would speculate there may be a short beam under the ridge beam supported at the ends by king studs that run down on each side of the window below. The crack looks like what I would expect if the short beam sagged a little.

 

[IceNine]

If there are no tension ties, whats resists the horizontal thrust but a structural ridge beam?

As I mentioned earlier, it is possible to detail a roof with tension ties at the eaves only at the end walls with no structural ridge beam, with the roof acting as a folded plate to resist thrust.
It does involve detailing that is above and beyond what normal framing contractors are used to, which is why we rarely ever try it.

See the link for a great document on the subject.

http://files.engineering.com/downlo...6&file=Report_121_-_Plywood_Folded_Plates.pdf

 

[mbullism]

You all are discussing apples and zebras... CAN it be done? Sure. Based on what's in the photo, what we know about common carpentry, and assuming half the code required minimum sheathing nails are over-driven, that beam is holding up half the roof... and you're taking the OP through a college lecture for nothing, lol.

Patch the crack

Analog spoken here...