# Big Bird - Pass/Fail



## Darren Emery (Apr 25, 2011)

Pass / fail the roof framing shown? Let's say the span would allow for a 2x6, aproximately what is left above the bird's mouth cut - pass?

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## fatboy (Apr 25, 2011)

To begin with, the member was not graded as a 2 X 6. It looks like this is an underframe for a vaulted area, so the dead load would be to the underside? I've allowed it before when the entire loads were going to be applied to the top of the member, but this one I'd have them provide an enginners analysis. JMHO


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## mark handler (Apr 25, 2011)

Is that a crack in the first member?

If the span would allow for a 2x6, aproximately what is left above the bird's mouth, I would allow it.


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## Mac (Apr 25, 2011)

Fail - the birds mouth cut shown is in excess of the notch limits of R802.7. However, if it is not really a roof rafter, it might be OK because it isn't structral. I guess I'd need to see it...   Weight bearing cuts like these are prone to uncontrolled splitting at the inside of the corner, and I think its already starting to split.


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## Darren Emery (Apr 25, 2011)

The members with the bird's mouth become the exterior roof plane about half way up the vault.  So it's carrying the roof live load on the upper half of the span, the ceiling load for the entire length, and a portion of the garage roof framing where it intersects the main roof line.


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## High Desert (Apr 25, 2011)

I wouldn't pass it. I would suggest joist hangers that were rated to carry whatever load is on them for a fix, though.


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## Mac (Apr 25, 2011)

Well if it's rated for a 2X6 maybe they shoulda used a 2X6.


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## permitguy (Apr 25, 2011)

Due to the grading issue raised by fatboy, I'd require an engineers report for the file.


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## GHRoberts (Apr 25, 2011)

I think the information should have been written as:

"2x6s are sufficient for the span and load; these elements are 2x8s. The issue is the notch at the end."

I don't see a grading issue if we removed 2" from the bottom of the elements and made them into 2x6s. Then the notch would be code complaint - even with the splits.

Unless there is another issue that I am not seeing ...


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## Inspector 102 (Apr 25, 2011)

I see this quite often because of the R-value that needs to be achieved. Structurally a smaller member could be used, but thermally that use it for insulation space. I have approved these cuts as long as they are clean cuts. Some have put backer blocks and face nailed from the back side to pick up the oversized lumber. I never really considered it a violation of the grading stamp, but good point.


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## pwood (Apr 25, 2011)

High Desert said:
			
		

> I wouldn't pass it. I would suggest joist hangers that were rated to carry whatever load is on them for a fix, though.


hd, the voice of reason!


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## RJJ (Apr 26, 2011)

The lack of a stamp on the material is an issue. This seems to becoming more of an issue with the big box stores. IMHO!

The sole cut is not correct to the letter of the code, however, if the imposed load is able to be carried by a 2x6 and the need for greater depth is needed for insulation the not a big deal. The over cut could have been done in compliance with the code if the carpenter new how to lay it out correctly! Just poor workmanship!

I agree with HD that hanger or hold downs are needed. I would approve it if it works span, exceeds imposed loads, and is tied together properly.

Some raise the question regarding a crack! It appears from the photo that it is a grain from a branch. These are common when a log is planked.


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## Jobsaver (Apr 26, 2011)

I agree with all points summarized by RJJ, but the workmanship is not necessarily bad once the hangers are added. Maybe the framer dropped the bottom of the joist below the plate in order to match the particulars of the construction on the side of the vault not shown?


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## RJJ (Apr 26, 2011)

Jobs: Good point. I am to use to hacks! Must be getting old!


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## Mule (Apr 26, 2011)

It appears they have added blocks to the studs and nailed blocks under the top plate so that the bottom of the rafter is not just hanging out in the wild blue yonder! To me unless they put blocks between the rafters the blocks they have installed "under" the toe of the rafters are mute.

The rafters need something to keep them from failing.

On another note, how many times do you see a similar situation where you have a ridge splitting two sets of rafters and you have the same situation. The toe of the rafter does not have anything supporting it. A birds mouth is just creating a point to fail.


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## Jobsaver (Apr 26, 2011)

Mule said:
			
		

> On another note, how many times do you see a similar situation where you have a ridge splitting two sets of rafters and you have the same situation. The toe of the rafter does not have anything supporting it.


Results in a correction notice around here.

2009 IRC (Bold type and italics mine)

R802.3 Framing details. Rafters shall be framed to ridge board or to each other with a gusset plate as a tie. *Ridge board shall be at least 1-inch (25 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 bearing partition or be designed to carry and distribute the specific load at that point. Where the roof pitch is less than three units vertical in 12 units horizontal (25-percent slope), structural members that support rafters and ceiling joists, such as ridge beams, hips and valleys, shall be designed as beams


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## Mule (Apr 26, 2011)

Here is the situation I was talking about. The ridge is full depth but.......
	

		
			
		

		
	

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## Jobsaver (Apr 26, 2011)

Mule said:
			
		

> Here is the situation I was talking about. The ridge is full depth but.......
> 
> 
> 
> ...


It is true that a picture is worth a thousand words.

In your example, I consider only the portion of the board serving the gable to meet the definition of a ridgeboard. The balance of the board is serving as a purlin, and the rafters attached above the purlin should be supported on bottom by hangers or a ledger. I have had cases where, as a correction, a second purlin was added beneath the foot of the upper rafters on this type of example.


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