# Lateral restraint on load bearing gable walls



## jar546 (Sep 15, 2010)

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.


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## vegas paul (Sep 15, 2010)

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.


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## pyrguy (Sep 15, 2010)

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.


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## jar546 (Sep 15, 2010)

vegas paul said:
			
		

> 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.


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## GHRoberts (Sep 15, 2010)

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


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## Yankee (Sep 15, 2010)

vegas paul said:
			
		

> 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?


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## Mule (Sep 15, 2010)

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.


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## TJacobs (Sep 15, 2010)

Should be an easy fix.


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## ajweaver (Sep 15, 2010)

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.


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## Enginerd (Sep 15, 2010)

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.


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## ajweaver (Sep 15, 2010)

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.


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## Mule (Sep 15, 2010)

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.


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## rktect 1 (Sep 15, 2010)

GHRoberts said:
			
		

> 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.


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## Code Neophyte (Sep 15, 2010)

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?


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## TJacobs (Sep 15, 2010)

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


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## GHRoberts (Sep 15, 2010)

rktect 1 said:
			
		

> 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.


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## Yankee (Sep 15, 2010)

ajweaver said:
			
		

> 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".
> 
> ...


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?


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## Mule (Sep 16, 2010)

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


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## Uncle Bob (Sep 16, 2010)

Code Neophyte,

" in §R802 "

How did you make that § ?

Uncle Bob


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## Mule (Sep 16, 2010)

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.


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## rktect 1 (Sep 16, 2010)

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.


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## TJacobs (Sep 16, 2010)

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.


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## brudgers (Sep 17, 2010)

jar546 said:
			
		

> 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.


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## brudgers (Sep 17, 2010)

TJacobs said:
			
		

> 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.


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## ajweaver (Sep 17, 2010)

Code Neophyte said:
			
		

> 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?


My response comes from an engineering perspective. That is what we do here on our designs.

Just to clarify-I am an inspector, not an engineer. I work for an engineer.

 I asumed the perpendicular joist should be part of a diaphram.

If the ceiling/rafters were parallel and on the top plate faced nailed together -

but

the ceiling joists were in a closet and only 2' long,

we could have the same scenerio as finger joists.

Personally, I would approve the finger joist/tie/outlooker scenerio, even without the engineer affiliation.

I could see that it is not 100% prescriptive, and someone might request an engineer to evaluate.

Either way is good for me.


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## brudgers (Sep 17, 2010)

ajweaver said:
			
		

> Personally, I would approve the finger joist/tie/outlooker scenerio, even without the engineer affiliation.


On what basis?


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## jar546 (Sep 18, 2010)

ajweaver said:
			
		

> Personally, I would approve the finger joist/tie/outlooker scenerio, even without the engineer affiliation.
> 
> I could see that it is not 100% prescriptive, and someone might request an engineer to evaluate.
> 
> Either way is good for me.


Hence where the problem in our industry, the first sentence:

IF we are enforcing a standard and are only certified at the level of inspector, we have no choice than to follow the prescriptive code or request engineering approval.

It is not what we "like" or think will be OK, but it is what is written and legally adopted.  This is especially true with structural issues that can be easily engineered.

These inconsistencies and varying opinions that have a great effect on contractors is what creates complaints and ill feelings from them.  The contractor in my town would be PO'd because he was given a choice of doing it over to meet the code prescriptively or get an engineer's approval/repair spec.  What I would hear from her/him would be " But I just did the same thing in XYZ town and their inspector approved it!"  The bottom line is that they would not learn anything and be making the same mistake again because the code was not properly enforced where they just worked.

That is what we don't need.

I know that ajweaver was simply his/her opinion and it may not be how ajweaver would make an official judgement but I am simply making this an example of one of the biggest problems in our industry.  Please take no offense aj.


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## Mark K (Sep 18, 2010)

I agree with jar546.  The same issues apply to plan checkers.

In addition I suggest that inconsistent and what appears to be arbitrary requirements can have a negative impact on quality of the work because some individuals will say why try and not make an effort.


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## peach (Sep 18, 2010)

looks like collar ties may be installed.  It LOOKS like 2x4 rafters (which is an issue with new growth lumber).

Rafter construction takes some really close scrutiny at plan review.. shouldn't be up to the field inspector.


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## GHRoberts (Sep 18, 2010)

jar546 said:
			
		

> IF we are enforcing a standard and are only certified at the level of inspector, we have no choice than to follow the prescriptive code or request engineering approval.


Not quite true. You can approve construction based on "local" construction practices. No reason to require engineering on work where similar engineering has been submitted in the past.


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## Mark K (Sep 18, 2010)

GHRoberts

Where in the code does it say you cn use calculations from a previous project to justify something on this project?


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## GHRoberts (Sep 18, 2010)

Mark K said:
			
		

> GHRobertsWhere in the code does it say you can use calculations from a previous project to justify something on this project?


Let's say the guy across the road built an identical structure and submitted all the engineering that AHJ asked for. The construction was approved by the AHJ last week. Sounds like I don't need to submit anything.

As ajweaver said: He saw such construction approved before. And he is willing to approve it now.

Prior experience is very important.


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## Mark K (Sep 19, 2010)

There are several problems with that logic.

First it is very rare that two structures are exactly the same.  They often differ in some aspect that you or the contractor may see as minor but to the engineer it is a big deal.

One thing that can change from one lot to another is the soil under the foundation.

The engineer who prepared the design for the first project was only paid to accept the risk associated with that project.  There have been situations where people have reused the design of the engineer without permission and without paying him for the reuse and when there were problems suing him for having contributed to the problem.  This puts the engineer at risk without getting paid and without having a chance to help mitigate any problems.  This is a real risk for engineers.

If the state engineering registration laws required that certain part of the work be designed by a licensed engineer then you are in violation of the state laws governing the practice of engineering.

The engineer and the architect could sue the owner of the second project for reusing the plans without permission.

You are not enforcing the building code as adopted. If calculations were required for the first project they are required for the next one.

By the way local construction practices are not recognized by the building code unless they have been codified and adopted by the local jurisdiction.

See the posting by jar546


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## Rio (Sep 19, 2010)

Good points on the dangers and fairness of re-using engineered systems, but it does make sense that in an area, if there is an accepted and common building practice that has stood the test of time that should be taken account.

 1st thing I'd do is run a row of blocking along the top of the beam where the c.j.'s overlap, then a few rows of continuous blocking between the c.j.'s at some spacing, 32" o.c. or 48" o.c. in the same direction as the blocks on top of the beam along with rafter ties at some spacing.  This would be a simple calc. for an engineer or architect who can do engineering.


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## brudgers (Sep 19, 2010)

GHRoberts said:
			
		

> Not quite true. You can approve construction based on "local" construction practices. No reason to require engineering on work where similar engineering has been submitted in the past.


Engineering doesn't become proper just because it was submitted, and any construction practice can be improperly applied.


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## brudgers (Sep 19, 2010)

GHRoberts said:
			
		

> Let's say the guy across the road built an identical structure and submitted all the engineering that AHJ asked for. The construction was approved by the AHJ last week. Sounds like I don't need to submit anything. As ajweaver said: He saw such construction approved before. And he is willing to approve it now.
> 
> Prior experience is very important.


Just because you got a permit, doesn't mean you met the code.


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## Mac (Sep 20, 2010)

A couple of points, in no particular order...

"That's the way we always do it" isn't quite good enough for me to approve a project, so follow the perscriptive or get some plans prepared by a design professional. I need the info I need for a reason. My files are subject periodic audits and I want them complete.

"Sounds like I don't need to submit anything." Yes you do, kind of like providing plans for each duplicate of the stock houses built in a tract full of houses.

"We don't need to do that in XYZ town". So go back there and build it.

"Just because you got a permit, doesn't mean you met the code." Well, it should mean the proposal meets code, but in actual aplication, well...


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## TJacobs (Sep 20, 2010)

See Figure 52 on Page 42 here:

http://www.awc.org/pdf/WCD1-300.pdf

Maybe the problem is we see so little "conventional wood frame construction"?


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## GHRoberts (Sep 20, 2010)

The most wonderful part of me being an engineer is that I submit just floor plans and a few notes - indicating that I know the code required loadings.

Then I ensure that the construction meets the intent of the plans and notes.

I don't wait for permits or inspections. (I have not had to since a court told the AHJ not to harass me.)


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## Yankee (Sep 20, 2010)

GHRoberts said:
			
		

> I don't wait for permits or inspections. (I have not had to since a court told the AHJ not to harass me.)


. . . . wow . . . .


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## fatboy (Sep 20, 2010)

yeah..........


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## mtlogcabin (Sep 20, 2010)

> Then I ensure that the construction meets the intent of the plans and notes


Most engineers never see the installation/construction of their designs. Glad to see you are the exception and willing to get out in the field and make sure the contractors are following your design.


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## texasbo (Sep 20, 2010)

GHRoberts said:
			
		

> The most wonderful part of me being an engineer is that I submit just floor plans and a few notes - indicating that I know the code required loadings.Then I ensure that the construction meets the intent of the plans and notes.
> 
> I don't wait for permits or inspections. (I have not had to since a court told the AHJ not to harass me.)


I'm calling B.S. on this one; I don't believe a single word of it. It's a blowhard post if I ever saw one. Requiring you to comply with the law is not "harassing" you.  A court isn't going to exempt you from ordinances, even if the AHJ DID harass you. That's not really how the law works, George. And no jurisdiction is going to allow you to "just submit a floor plan and a few notes", unless of course, you're engineering a floor plan...

George, are you a registered professional engineer? If so, in what states are you registered to practice engineering?


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## Rio (Sep 20, 2010)

Some places you don't even have inspectors but that's the exception.  There's no way in most parts of the country that just because you're a civil or structural engineer that you aren't going to have to submit plans and justify your calcs with figures.  Also, having worked with a lot of engineers, some are good, some are terrible, and a few are great


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## ajweaver (Sep 20, 2010)

brudgers said:
			
		

> On what basis?


If installed properly, I believe it meets the intent of the code.


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## ajweaver (Sep 20, 2010)

jar546 said:
			
		

> Hence where the problem in our industry, the first sentence:IF we are enforcing a standard and are only certified at the level of inspector, we have no choice than to follow the prescriptive code or request engineering approval.
> 
> It is not what we "like" or think will be OK, but it is what is written and legally adopted.  This is especially true with structural issues that can be easily engineered.
> 
> ...


No offense at all.

I do understand your point jar546,

You said:

 " IF we are enforcing a standard and are only certified at the level of inspector, we have no choice than to follow the prescriptive code or request engineering approval."

Technically yes,

but there are many instances where construction does not match wording of code,

but I know the intent and do not need engineering to achieve/exceed that.

But I am open to constructive criticism..Is that wrong?

How I was taught is that this particular installation (when intalled correctly) is a "connection of equivalent capacity" and meets intent of the prescriptive code.


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## Mule (Sep 21, 2010)

Oh my gawsh aj....someone with common sense!!! What is wrong with you?


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## Yankee (Sep 21, 2010)

ajweaver said:
			
		

> How I was taught is that this particular installation (when installed correctly) is a "connection of equivalent capacity" and meets intent of the prescriptive code.


I don't necessarily disagree, but can some of you engineers please comment on whether this installation is likely to "(when installed correctly) is a "connection of equivalent capacity".

I'd like to know if ajweaver was directed appropriately (from what you can tell). ok?


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## brudgers (Sep 22, 2010)

TJacobs said:
			
		

> See Figure 52 on Page 42 here:http://www.awc.org/pdf/WCD1-300.pdf
> 
> Maybe the problem is we see so little "conventional wood frame construction"?


Note that the subflooring turns the ceiling into a diaphragm and ties the walls together.

Subflooring in the attic is not really typical practice, even though the framing is conventional.


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## Yankee (Sep 22, 2010)

And note the metal straps which share the load to more than the one ceiling joist. Attic subfloor is common around here and changes the nature of our discussion as brudgers points out.


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## TJacobs (Sep 22, 2010)

brudgers said:
			
		

> Note that the subflooring turns the ceiling into a diaphragm and ties the walls together.Subflooring in the attic is not really typical practice, even though the framing is conventional.


Correct.  You could possibly accomplish the same thing with rafter ties every 4th rafter on top of the ceiling joists in accordance with R802.3.1.

My point is I could show the WFCM detail to the builder without getting an engineer involved, builder's choice.


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## Yankee (Sep 22, 2010)

TJacobs said:
			
		

> Correct. You could possibly accomplish the same thing with rafter ties every 4th rafter on top of the ceiling joists in accordance with R802.3.1.My point is I could show the WFCM detail to the builder without getting an engineer involved, builder's choice.


How did you determine the every 4th rafter spacing?


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## TJacobs (Sep 22, 2010)

Yankee said:
			
		

> How did you determine the every 4th rafter spacing?


Oops...past practice.  1998 IOTFDC (our previous code):

_802.3 Framing details._

_Rafters shall be nailed to ceiling joists to form a continuous tie between exterior walls where joists are parallel to the rafters. Where not parallel, rafters shall be tied with a rafter tie, located as near the plate as practical. __*Rafter ties shall be spaced not more than 4 feet (1219 mm) on center.*__ Rafters shall be framed to ridge board or to each other with gusset plate as a tie. Ridge board shall be at least 1-inch (25.4 mm) nominal thickness and not less in depth than the cut end of the rafter. At all valleys and hips there shall be a valley or hip rafter not less than 2-inch (51 mm) nominal thickness and not less in depth than the cut end of the rafter. Hip and valley rafters shall be supported at the ridge by a brace to a load-bearing partition or be designed to carry and distribute the specific load at that point._

That is not in the 2006 IRC...my bad!  However, it WAS good enough in 1998.  Thanks for the catch.

BTW, there is a definition for rafter tie in the WFCM.


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## brudgers (Sep 22, 2010)

TJacobs said:
			
		

> Correct.  You could possibly accomplish the same thing with rafter ties every 4th rafter on top of the ceiling joists in accordance with R802.3.1.My point is I could show the WFCM detail to the builder without getting an engineer involved, builder's choice.


Using ties every fourth rafter isn't the same thing, because the non-triangulated  rafter are bearing at the ridge and placing thrust on the top of the wall.

In the diagram, all every rafter pair is fully triangulated by the floor diaphragm so it doesn't matter which way the joists run.


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