Are roof rafter notches allowed

There were notches in one rafter, which was on a portion of the home that was an exterior wall. They were about every 2 feet or so. Are notches in rafters allowed? I do not think they are according to the code book but am not entirely sure.

DSCN5267.JPG

Notching on those trusses would not be allowed without written exceptions and specific instruction (maintained on site) from the AOR (or EOR) who designed the cuts into them…

IRC 802.10.4 and UBC 2320.1 calls out no field modification except with engineer approval.

I am concerned that the depth appears at approximately 50% of the chord.I would be additionally concerned if the notch were on the tension side of the chord instead of the compression. If there are no markings or approval notes on-site, I personally would call it out.

Does this also apply to gable end trusses?
They are not built the same way and do not serve the same purpose and field trusses.

I’m more curious as to the contruction of the overhang on the other side of the end truss.

Usually the last truss is made shorter (“dropped” 3 1/2) so the lookout blocks can span from the last tall truss over the top of the shorter end truss and support the fly rafter that forms the projected rake.

I’d say “no” to cutting the trusses, any way shape or form, without the written approval from the Truss Manuf.
Look at the cuts, the truss seems to be notched approx. 50% and ragged at that. Note the lower (left) notch of the truss.
I’d write up as a structual change to the truss, and recommend further review.

Hi Ron,

That appears to be the gable end wall, if it is there is no load
there to speak of and I would not write this up.

CJ

I agree with with Greg and recommend further review. Down here in TX, I’ve seen the last truss (as in the picture) doubled to reinforce a gable end.

Trusses, when exposed to fires, are dangerous enough without having them compromised by cutting.

My .02 cents
Bruce

I always recommend writing up any field modifications or cuts to trusses, unless there is documentation stating otherwise (rarely on-site).

JMO

Always call out any modifications to trusses. They are not to be field-altered without engineer-approved designs which have to be inspected by a building official after changes are made.

You assume liability if you leave it out.

“Trusses with visible field alterations were visible in the roof framing. Altering of trusses in the field requires engineer-approved designs which must be inspected and approved by a building official after changes are made. You should ask the sellers to provide documents showing that alterations to the trusses were inspected and approved by the proper authorities.”

This type of notching is done on almost every gable end truss in California. The work done in the picture looks very clean!

I would note it in your inspection report to cover any potential liability but I would not recommend further evaluation.

If the gable end truss sits over an exterior wall it will be continuously supported. These trusses will typically be designed as a drag truss and take into account the notching.

1 Like

I was looking at it wrong. With the gabled end sheathed and typically nailed off at 6&12 it should be fine. I guess I’d mention it but structurally it’s not going anywhere.

Up here, notching the gable end truss is common, it is done to support the lookouts and fascia on the end of the gable. Since the webbing in the truss is vertical, it is considered by Building inspectors to be ok. More truss makers are switching to drop gables where the only notching is on the 2X6 outrigger itself.

Those gable trusses are notched for outlookers. Typically in the truss calc package that is submitted, there is a detail showing this notch detail. Remember that this truss is covered with sheathing and sits on a continuous bearing wall.

Yes, it is generally OK. Many time the calc’s include a pre-req for nailing a 1 x 4 under notches on a gable end.

Those outlookers using 2x4’s on the flat indicates to me that someone made an error on the truss fabrication due to lack of information by the designer or person that ordered them.
Typically, around here, anyways, the gable end truss is always dropped to accommadate the overhang outlookers.

DROPPED TOP CHORDS

http://www.tricountytruss.com/images/Trusses/Addon7.JPG

Dropping the Top Chord, in this example by 3-1/2’’, is an ideal way to make the space to add outlookers on edge.

http://www.alpeng.com/robohelp/ADH%20System/!SSL!/FlashHelp/figure_01_DTC_Example.gif

http://www.alpeng.com/robohelp/ADH%20System/!SSL!/FlashHelp/Figure_01_Example_of_Gable_Ladder.gif

This is the standard of practice for gable overhangs.

Since the notches I see, dose not bother me structurally, and it is not going anywheres, my only concern would be how wide is that overhang and what dose it look like?

If it goes out to far, you will see a curl in the roof plane of the roof profile.

Hope this helps a little. :):smiley:

Standard method of framing an overhang on a gable end. Sometimes that last truss (or two) is made 1 1/2-inches smaller to allow that framing to pass over it without notching, but I would assume the truss manufacturer took the notches into account when designing that truss. It can be verified if the truss engineering drawings can be found and examined.

It is not correct to call them rafters, they are the top chords of a manufactured truss. So different rules apply, as you see from the comments so far. :stuck_out_tongue:

John Kogel
www.allsafehome.ca

The drop top chord doesn’t work in my area. The shear connection between the roof sheathing and the gable end drag truss becomes an issue. You would need to provide a block between each outlooker and a framing anchor from each block to the top chord. However, the nailing of the sheathing into a 1 1/2" thick block does not provide adequate nail penetration.

I have seen truss companies that provide a double top chord. The top-top chord is cut for the outlookers. The bottom-top chord is the structural element of the truss. Gang plates transfer the load between the double top chords. The top-top chord is on end so you get adequate nail penetration.

You can write this up to cover you liability. However, requiring a structural review can be costly for your client and not required. I get lots of calls regarding modified trusses found/noted by home inspectors. Only once was there a structural issue.

I hope this helps.

Bingo Mr. Combs.

As a contractor, I haven’t seen any dropped top chords for gable ends on truss system in my neck of the woods, as mentioned when I’ve notched gable ends for outriggers/lookers for fascia per truss calcs/plans. You’d otherwise be committing hari-kari :slight_smile:

I’ve seen framing members/ends resting on hip carrier system with above mentioned double top chords where hips intersected only partially and had partial fascia/eave at top/intersecting area… you know the ones that you have to slide up under and moan and groan to yourself when painting… Double top chord (or 2x6 top chord too) where notching occured.

Anything is better than a simple plant-on lookout (ladder) type fascia that hangs out and sags over time. Unless that is, someone notched a truss and made a boo boo.