stud notching, code clarification

[Wendell Swedberg]

R602.6.1 states (Bold & underline is mine),

"Any stud in an exterior wall or bearing partition may be cut or notched to a depth not exceeding 25 percent of its width..."

From and ICC practice examine question:

Q: Can a notch 1 1/2 inches deep be made in a nominal 2x6 exterior wall stud?

A: No

So what am I missing because I say yes....25% of 6 = 1.5" the code says not exceed 25% so being equal to 25% (1.5") should be fine.

thanks

[Jerry Peck]

So what am I missing because I say yes....25% of 6 = 1.5" the code says not exceed 25% so being equal to 25% (1.5") should be fine.

thanks

25% of 5.5 = 1.375

You need to use the "actual" measurement for notching and boring.

[Wendell Swedberg]

Now for a bigger , silly question...how / where do you get 5.5"?

Having said that, 1.375 inches is still less than 25% so either way (1.375 or 1.5 inches) , it's in compliance. Thus the test answer is wrong.

[Jerry McCarthy]

Wendell
All stick framing lumber is sized 1/2" less then its call-out dimension. Back in the old days, pre WW II they where actually full sized, 2x4, 2x6, 2x8, etc., however that changed during the war and has been the protocol ever since. Jerry P's math is bang-on.

[Brandon Chew]

Now for a bigger , silly question...how / where do you get 5.5"?

Having said that, 1.375 inches is still less than 25% so either way (1.375 or 1.5 inches) , it's in compliance. Thus the test answer is wrong.

Ditto what the tag-teaming Jerrys said.

The key info was "nominal" 2x6, which is 5.5 inches actual dimension.

The 25% limit means the notch can't be any deeper than 1.375... cutting one 1.5 is deeper than what is allowed.

[Jerry Peck]

Having said that, 1.375 inches is still less than 25% so either way (1.375 or 1.5 inches) , it's in compliance. Thus the test answer is wrong.

Wendell,

The 1.375" I posted is the maximum permissible notch, not the 25%, a 1.5" notch exceeds that 1.375" maximum allowable notch.

The test question is right.

Added with edit: (Dang, should have read down to Brandon's post before I replied, Brandon already covered it.)

[Markus Keller]

The question raises any interesting thought about trade practice. Plumbing walls typically have been framed 2x6 up here. Stacks running vertical of course not a problem. However the 1.5" vents and revents are drilled through the 2x6 studs for connection to the stack.
Under that question plumbing walls would need to be 2x8 minimum. I've never seen that sofar. I find it unlikely any carpenter and plumber are going to get together on that.
What has become somewhat more common is double framed walls, 2x4 on each side with space in between for piping.
Just a comment.

[Jerry Peck]

However the 1.5" vents and revents are drilled through the 2x6 studs for connection to the stack.

Did you catch the difference in what you just stated and the original question?

Original question: "cut or notched"

You stated: "drilled through", i.e., "bored"

Bored holes may be larger than "cutting and notching".

Exterior and load bearing walls: cutting and notching = 25% / bored holes = 40%

Interior and non-load bearing walls: cutting and notching = 40% / bored holes = 60%

With an interior wall, non-load bearing, a bored hole in a 2x6 (5.5 inches actual) could be as large as 3.3 inches as long as the edge of the hole is no closer than 5/8" to the edge of the stud (basically centered in 2x6 stud).

Does that makes thing work out better for what you see?

[Markus Keller]

Ah yes, master Obiwan
You are correct. I did not read the post that closely and 'see' "cut and notched" in opposition to my reply.
I will retreat to the swamp to practice lifting my X-wing

[Jerry McCarthy]

Diagrams are always helpful