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Roof frame pics to make you smile

Maybe he used structural drywall???? GR could get that to work with some engineering....that first pic MIGHT work under the prescriptive notching.....that valley rafter is way not good...although I have seen them stamped that way.....
 
Sifu said:
http://i1269.photobucket.com/albums/jj584/raspicher/HPIM0077.jpgHow would the rafter work prescriptively? Max notch is 25%, this one is 50%. Are you employing the exception because if that permits it then I need to back off this correction if he has 4". I was under the impression that this is not what the exception addressed.
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It is not possible to make a determination without all of the details. It could be that the rafter is twice as large as would be required. A picture from 10' away would help. There doesn't appear to be a connection of the roof diaphragm to the wall because there are no frieze blocks or wall top plates visible, etc.
 
The rafter is over-spanned and there is no rafter tie (other corrections noted on the inspection) but how is that relevant to the prescriptive code? The code limits the notch (without exception) to 25% without mention of required rafter size or rafter ties. I was taught that it didn't matter since the danger of splitting along the grain on a notch could potentially reduce the member to nothing. This thread now has a kind of sister thread concerning the span issue, sorry I didn't want to mix the issues but it looks like it happened anyway.
 
remove drywall for reinspection of framing corrections not cleared through proper inspection process. refer to R109.4 2006 IRC.
 
Sifu said:
The rafter is over-spanned and there is no rafter tie (other corrections noted on the inspection) but how is that relevant to the prescriptive code? The code limits the notch (without exception) to 25% without mention of required rafter size or rafter ties. I was taught that it didn't matter since the danger of splitting along the grain on a notch could potentially reduce the member to nothing. This thread now has a kind of sister thread concerning the span issue, sorry I didn't want to mix the issues but it looks like it happened anyway.
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If your code language is the same as ours here in Canada it will say something along the line of "notching shall not exceed x in size unless the depth of the member is increased by the size of the notch"
 
+ + +

I agree with "codeworks" suggestion also, ...remove all drywall

for proper inspection of all of the framing.....For a "fix" for the

overnotched roof rafter, I'm guessing that requiring a

competent RDP is out of the question.

What we have allowed in the past was to have custom made

pieces of plate steel, ...3.8" thick, that covered the entire width

of the rafter, ...on both sides and bolted thru the rafter.....It

was not an RDP design......We have since started using RDP's to

submit a compliant design......This practice / requirement has

stopped most of the obscenely overnotched framing members

[ for the most part ].......Once the contractor community knows

that you will not approve their discrepancies and move the

project forward, they have [ here ] tended to improve their

practices.

I'm pretty sure I know the answer ahead of time, but can

you require the removal of the drywall and possibly an

engineered fix for the "overnotching" & any other issues?

Also, "thanks" for your continuing transparency!

+ + +
 
The code limits the notch (without exception) to 25% without mention of required rafter size or rafter ties. I was taught that it didn't matter since the danger of splitting along the grain on a notch could potentially reduce the member to nothing
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If the rafter ended at the top plate with no overhang would you approve it where it is bearing on the top plate or should the rafter be bearing closer to the heel than the toe (sheathing side) of the cut.

Don't get hung up on the knotching requirements it may not be a problem but hard to tell from the picture.
 
$ $ $

From Section R802.7.1 - Sawn lumber [ `06 IRC ]:

Notches in solid lumber joists, rafters and beams shall not exceed one-sixth

of the depth of the member, shall not be longer than one-third of the depth

of the member and shall not be located in the middle one-third of the span.

Notches at the ends of the member shall not exceed one-fourth the depth

of the member........The tension side of members 4 inches (102 mm) or

greater in nominal thickness shall not be notched except at the ends of the

members.........The diameter of the holes bored or cut into members shall

not exceed one-third the depth of the member........Holes shall not be

closer than 2 inches (51 mm) to the top or bottom of the member, or to

any other hole located in the member........Where the member is also

notched, the hole shall not be closer than 2 inches (51 mm) to the notch.



Exception: Notches on cantilevered portions of rafters are permitted

provided the dimension of the remaining portion of the rafter is not less

than 4-inch nominal (102 mm) and the length of the cantilever does not

exceed 24 inches (610 mm).

$ $ $
 
Sifu said:
http://i1269.photobucket.com/albums/jj584/raspicher/HPIM0077.jpgHow would the rafter work prescriptively? Max notch is 25%, this one is 50%. Are you employing the exception because if that permits it then I need to back off this correction if he has 4". I was under the impression that this is not what the exception addressed.
Click to expand...
I don't think that notch is 50%.....it may be more than 25%.....it should be measured from the bearing point perpendicular to the grain in that case...I hate when they mess up the seat cut like that....
 
The "notch" appears to be the unsupported 1-1/4" that is beyond the 6" seat cut. The code language does a poor job here, it should prescriptively say "the seat cut should not extend beyond the plate". Right now it says it can extend inboard off the bearing till it erodes 25% of rafter depth, he is golden but it's not right. No different than a sharp 2x2 ledger notch, specifically allowed and causes splitting.
 
OK, I'll readily admit I'm not the sharpest chisel in the tool box so I can ask these questions and not feel too much more uneducated.

-If a rafter of 7 1/4" depth is notched with a birdmouth/seat cut, and the depth of that cut measured perpendicular to the grain of the rafter is 3 1/2" to 4", and that notch is on the end/bearing point of the rafter, is it not notched 45% to 50%?

-Doesn't the exception refer to the tail of the rafter, in other words the cantilever portion is the portion extending out after the bearing point? Thus limiting the tail to

4"x24" and having nothing to do with the depth of the notch.

-Therefore is not this rafter excessively notched? How would he be golden?

-Am I measuring the depth of the notch from the wrong point? In the photo the outer edge of the seat cut is 3 1/2" to 4" but the inner edge may only be 1 1/4". Is that where I am not getting this?

-Doesn't this tie into into the location of the bearing point brought up previously?

-Finally, I don't know what NorthStar means by me being transparent, is that good or bad?

BTW, I have informed the owner that for me to sign anything the corrections will need to be made or a DP will need to sign off and that for the corrections to be observed the drywall will need to be removed. Some of the corrections I don't have prescriptive corrections for, like the rafter notch, thats why I'm trying to make sure of my understanding of the actual code language. If I am wrong it will cause him a lot of time and money and I don't want to do that. (every rafter in the house)
 
Everyone is being positive with you Sifu, no worries there.......The notch depth is measured square off of the bottom edge of the rafter and ends at the bearing point...it is not the length of the seat cut.....I agree it is hack work, but it looks like it might be close to being compliant...(tough to tell from here)....the valley rafter is a whole different different ball game however...
 
Nifty notching. Rafter load carrying capability severely compromised. Much more susseptible to shear that if it had been left full sized.
 
Sifu,

Northstar paid you a big compliment. Mr Edwards who was aquitted today, not very transparent.

I saw mention of these being finger jointed rafters. I've never used finger jointed lumber. My first question is whether this is an appropriate use and whether the design values are the same as the solid sawn dimensional values you are using in your tables. I would call the grading agency listed on the grade stamp unless someone here knows the answer to that.

If a rafter of 7 1/4" depth is notched with a birdmouth/seat cut, and the depth of that cut measured perpendicular to the grain of the rafter is 3 1/2" to 4", and that notch is on the end/bearing point of the rafter, is it not notched 45% to 50%?
Click to expand...
dhengr covered this bit in his response on the other thread, Look at your picture above the rafter is 7-1/4 wide the tape is showing 6" remaining, or a 1-1/4" notch. dhengr also mentioned the notch splitting along the grain out of the re-entrant corner of the notch. I've drawn a red line following the grain out of the notch. He then went on to explain that the grain can be highly variable and the split can run up into the board and cause serious problems. Imagine if the knot in this picture was a bit closer to the notch and then the split began. I followed that grain in green, see how the split would then run up deeply into the rafter. Slope of grain is very critical.

I've drawn in the repair I would do in the field if I drove up on this job.

notchedrafter.jpg


I would get out the sawzall and chuck up a long stiff blade. Make a full level seat cut on the black line dropping that dangling tip off. Slide in another long 2x4 flatways under the seat cut giving it full bearing. Have a pack of shims in your bags and make that snug. Secure both plates well to the ceiling joists and run a framing angle alongside the rafter nailing to the plate and to the rafter.
 
OK, I see that I misunderstood the point at which the notch should be measured. I was taking it from the tip of the seat cut at the outside. This being the case I agree that it is much closer to compliant than I thought. The irony is I attended a day long seminar taught by a local PE on framing last week, two days after this inspection. He brought up the problem of over-notched rafters, explaining how detrimental it can be to the structure. I guess it was just my preconception of the requirement and my (mis)understanding of his explanation that caused this. I am going to email him the picture and get his opinion, I'll let you know what he thinks.

I did take a good picture of the grade stamp so I can check on the lumber but my understanding about FJ lumber is that it is acceptable as a replacement for non FJ lumber. I have seen stress tests on it in the past and the failures occured at the solid portions while the FJ remained intact. This is something I have taken for granted for some time but if I am wrong and someone knows better please pipe in. I will do some better research as well.
 
Having read DRP and Dhenger's posts I think I finally get it but just to be sure, -the re-entrant notch is the inside cut that starts at the red line in DRP's corrective drawing and is across from the 6" on the tape in the picture? That is the critical point where failure will start and potentially split along the grain and that is where the notch refered to in the code should be measured from in relation to the bottom of the rafter.....correct? Thus any notch on a 7 1/4" rafter at this point deeper than 1 13/16" from the bottom of the rafter would exceed the limit of the code?

Please say yes.
 
Yes, I think he is fine by code. I told you what I would do and why.

That is the re-entrant corner. Stress concentrates, splits and cracks lead out of, inside corners.

I think your instructor was referring to thexception to R802.7.1, if there is an overhang beyond the birdsmouth there must be a 2x4 strap of rafter over the outboard corner of the plate, measured perpendicular to the rafter to support up to a 2' overhang.
 
I'm not saying that it's all wrong because it might be a regional way of framing but nothing about the framing in the picture looks right from here in CA. No connection of the roof diaphragm to the foundation. No frieze blocks. No solid blocking between the joists. No rafter tie. The 2"x that the rafter bears upon isn't nailed to the ceiling joist and if it were nailed the joist would probably split. And then there's that goofy seat cut.

A seat cut isn't a notch, it's the end of the rafter.
 
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