Lateral restraint on load bearing gable walls

[jar546]

1) The ridge is a board, not a beam.

2) The center beam is the only item that ties the side walls together but not the rafters.

3) You figure out the rest of this cluster.

 

[vegas paul]

I take it that you did not review a roof framing plan prior to granting this permit? I know that many jurisdictions do not require that level of detail for residences, however, this is an example of why complete plans should be submitted for SFRs.

 

[pyrguy]

Somebody actually stick framed a roof?!?!

The last single family stuff I did in Georgia almost always used trusses as the framers had no idea what was required to frame a roof.

I would sometimes run into an older carpenter that knew how to use a square for more than marking his wall layouts.

No one seems to think past the nose on his face anymore. It's get, get, get.

Get're done.

Get the check.

Get on down the road.

 

[jar546]

I take it that you did not review a roof framing plan prior to granting this permit? I know that many jurisdictions do not require that level of detail for residences, however, this is an example of why complete plans should be submitted for SFRs.

Excellent point. This is a neighboring community where we fill in for inspections as needed. I hope you can feel my pain when we are called out on stuff like this.

We were there for an electrical and mechanical inspection (local BCO did the frame and plumbing) but I could not resist this photo.

 

[GHRoberts]

I see ties at 4' (maybe 6') spacing.

 

[Yankee]

I take it that you did not review a roof framing plan prior to granting this permit? I know that many jurisdictions do not require that level of detail for residences, however, this is an example of why complete plans should be submitted for SFRs.

Cable ties anyone?

 

[Mule]

When joists are not parallel with the rafters you have to install rafter ties. That's the only problem I see is the correct placement of rafter ties.

Maybe span of rafters.

 

[TJacobs]

Should be an easy fix.

 

[ajweaver]

I wouldnt require rafter ties.

It looks to me the last ceiling joist closest to the exterior wall is doubled.

Hangered into that doubled ceiling joist are "finger joists".

Those "finger joists", if properly fastened to the rafters, proved adequate

resistence to "rafter thrust".

The top plate looks to be interupted with the beam.

I am not able to see the ridge to verify bracing, and I do not see a gable in the pic either.

 

[Enginerd]

It looks to me like there are some collar ties present, but hard to tell where and how many. Obviously they are less effective if they aren't on each rafter, and are less effective the closer to the ridge they are.

 

[ajweaver]

Enginerd,

Hey nice to meet you last week.

Collar ties are different from rafter ties.

Collar ties are in the upper 1/3 of attic to prevent uplift.

Rafter ties near top plate to provide restraint to rafter thrust.

Sometimes on a lower pitched roof with rafters to form ceiling

the serve as both.

 

[Mule]

It's hard to tell if those are collar ties or rafter ties. When joists are not parallel with the rafters then rafter ties must be provided. Rafter ties are located within the lower 2/3 rds of the attic.

In my opinion in this situation rafter ties should be on every rafter.

Remember there is a difference between rafter ties and collar ties. Both provide a different benefit to the structural integrity of the building.

We may be better off using the eggster straps on this one!!

Oh by the way..I saw these use of this metal/structural steel mesh at work this past weekend. I was in the mountains of Colorado and there was an area where rocks were very unstable and could have tumbled onto the road. There was a structural mesh installed on the side of the cliff to keep the rocks from tumbling onto the road.....looked like chicken wire on steroids. Had to be the stuff that eggster pushes.

 

[rktect 1]

I see ties at 4' (maybe 6') spacing.

If you pay an engineer to design it, sure. Otherwise they will need to add rafter ties at the same spacing as the roof rafters, looks like 24" o.c.

 

[Code Neophyte]

Ajweaver,

Another Denver attendee here. It was nice meeting you. I like your response above; I have used the same rationale often. I'm curious, though, as to whether your assessment is based in §R802, or if it comes from your engineering perspective?

 

[TJacobs]

Finger joists a.k.a. lookouts (to an old framer). Looking harder at the picture I would agree with ajweaver's assesment.

 

[GHRoberts]

If you pay an engineer to design it, sure. Otherwise they will need to add rafter ties at the same spacing as the roof rafters, looks like 24" o.c.

Jar546 said the walls were not tied together. I simply said there were ties. I made no comment on the code compliance.

I don't know what changes an engineer might want. That is up to the engineer. Lots of cheap ways to solve any load issue that might exist.

 

[Yankee]

I wouldnt require rafter ties.It looks to me the last ceiling joist closest to the exterior wall is doubled.

Hangered into that doubled ceiling joist are "finger joists".

Those "finger joists", if properly fastened to the rafters, proved adequate

resistence to "rafter thrust".

I see what you mean, but it still isn't prescriptive is it? How would one "judge" what the span of that last doubled ceiling joist would be allowed to be (how many finger joint "thrusts" can it withstand?). Shouldn't this be an engineered solution?

 

[Mule]

If the builder didn't want to install rafter ties...Yes!

 

[Uncle Bob]

Code Neophyte,

" in §R802 "

How did you make that § ?

Uncle Bob

 

[Mule]

Not CN but....

Alt 21

Make sure your number lock is turned on and play around with all of the number combinations.

Some interesting ones Alt 11 ♂ Alt 12 ♀ Alt 13 ♪ Alt 14 ♫

Play around with different combinations to get some different symbols. Alt 504 is the degree symbol 95° There is probably a different number for it but that's just the one I found.

 

[rktect 1]

I think the problem I have with the "finger joists" or "lookouts" when I read the code section is that these should not be perpendicular to the ridge board. Ceiling joists/rafter ties in bottom third are supposed to be perpendicular to the ridge board, not parralel. Think about a 20'x16' hip roof. the ridge board should be in the long direction the only portion of the hip not being protected from rafter thrust then would be the last 18 inches along the short direction. so you use the fingers/lookouts. The other way around makes no sense and would require the ridge board to be a beam.

 

[TJacobs]

You may want to look at the WFCM...I don't have my copy handy. The lookout is a common system.

As for the fancy characters, you could use "Character Map" which is under Start/All Programs/Accessories. It is also called an ASCII character...Google ASCII and there should be corresponding keyboard equivalent charts.

 

[brudgers]

1) The ridge is a board, not a beam.2) The center beam is the only item that ties the side walls together but not the rafters.

3) You figure out the rest of this cluster.

Rafters are placing thrust on the top of the wall.

The "finger ties" are not adequate unless they are part of a diaphragm because they are just transferring lateral load to the first perpendicular ceiling joist.

There's no lateral resistance and probably the connector isn't rated in that direction (though some are).

Of course there's nothing holding the ridge up either.

It's a rare case, where I'd say rip it out our give me engineering calculations...and I'd want calcs not some plan stamper's seal.

 

[brudgers]

You may want to look at the WFCM...I don't have my copy handy. The lookout is a common system.As for the fancy characters, you could use "Character Map" which is under Start/All Programs/Accessories. It is also called an ASCII character...Google ASCII and there should be corresponding keyboard equivalent charts.

That ain't gonna comply with the prescriptive requirements of WFCM.