320.23a

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tallguy said:
Forgive my ignorance, but I've always understood that as long as you drill out of the center of the stud/joist/rafter/truss/whatever -- and leave at least 1/3 of the width on either side, that the integrity of the wood would be maintained.

What makes an "engineered attic truss" different?
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You are not permitted to alter, drill, or notch and engineered truss, without the approval of the engineer.

You are permitted to drill or notch nominal lumber that is not part of an engineered truss system, such as a stick framed roof or floor.

Chris
 
There is a lot of misinformation out there about what can and cannot be drilled. Chris and Cavie are absolutely correct about not drilling an engineered truss.

I have been told by a building inspector that I could not drill a laminated beam. It may be the case sometimes but not all the time. I called the lumber company that makes them and they said 5/8" holes are fine. Obviously the hole sizes has a lot to do with what you can do.
 
Dennis Alwon said:
There is a lot of misinformation out there about what can and cannot be drilled. Chris and Cavie are absolutely correct about not drilling an engineered truss.

I have been told by a building inspector that I could not drill a laminated beam. It may be the case sometimes but not all the time. I called the lumber company that makes them and they said 5/8" holes are fine. Obviously the hole sizes has a lot to do with what you can do.
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A laminated beam is an engineered product the same as an I joist. The manufactures of the products will have charts and information on where and if you can drill a hole in their products. It is amazing to see how large a hole you can put in the center of a span of an I joist.

Chris
 
attics

attics

I started a thread about this in February:http://forums.mikeholt.com/showthread.php?t=84314&highlight=attic
and ...my being a bit dense....I'm still uncomfortable with it.
Marc, are you saying unless there is flooring being installed the section is not relative ? When does a main floor ceiling joist become an attic floor joist.
I'm still uncomfortable when I pull down a set of stairs and find a "sea of romex" on top of the "ceiling joists".
 
I disagree with Marc's interpretation of what constitutes a floor joist.

Therefore you may want to speak to your inspector first.


The way I read this is such:
If there are stairs to the unfinished attic space, including the pull down type stairs, then 320.23(A) should be followed.
This means that the entire floor (floor joists or surface) of the attic horizontally, including all the way to the eves (soffits) and up to 7 feet above the floor surface - vertically, the cabling will either be installed in bored holes or protected as per the section.
 
augie47 said:
I started a thread about this in February:http://forums.mikeholt.com/showthread.php?t=84314&highlight=attic
and ...my being a bit dense....I'm still uncomfortable with it.
Marc, are you saying unless there is flooring being installed the section is not relative ? When does a main floor ceiling joist become an attic floor joist.
I'm still uncomfortable when I pull down a set of stairs and find a "sea of romex" on top of the "ceiling joists".
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If you are pulling down a set of stairs, then it is a violation as per 334.23 (which will get you to 320.23 by reference), is it not?

This is what I have in my house -- drives me nuts. Replacing it bit by bit.
 
Dennis Alwon said:
There is a lot of misinformation out there about what can and cannot be drilled. Chris and Cavie are absolutely correct about not drilling an engineered truss.
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Fair enough... 2nd question is then "What constitutes an engineered truss?"

Anything that arrives on the job site preassembled is "engineered" and anything put together on site is "stick"?
 
tallguy said:
Fair enough... 2nd question is then "What constitutes an engineered truss?"

Anything that arrives on the job site preassembled is "engineered" and anything put together on site is "stick"?
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rafters and ceiling joists joined together as one unit made from 2x4's and 2x6's, manufactured off site and delivered on site by a big truck. They come with a set of manufactures install instructions sealed with an engineers stamp.
 
tallguy said:
If you are pulling down a set of stairs, then it is a violation as per 334.23 (which will get you to 320.23 by reference), is it not?
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Just went back and read the original thread... I agree with George's position (nice drawings too).

I do, however, also agree with the panel comments made vis-a-vis his proposal to grant relief on 320.23 if there is no floor installed. Unless there is no access whatsoever, attics are invariably going to be used for storing something.
 
attics

attics

Pierre C Belarge said:
I disagree with Marc's interpretation of what constitutes a floor joist.

Therefore you may want to speak to your inspector first.


The way I read this is such:
If there are stairs to the unfinished attic space, including the pull down type stairs, then 320.23(A) should be followed.
This means that the entire floor (floor joists or surface) of the attic horizontally, including all the way to the eves (soffits) and up to 7 feet above the floor surface - vertically, the cabling will either be installed in bored holes or protected as per the section.
Click to expand...

I agree 100% , but I'm jousting at windmills (alone) in this area. I''ve received zero support. At an IAEI meeting the only comment by CMP folks was it was routinely violated (and ignored)
 
The NEC should say "framing members" in place of "floor joists" if that's what they meant to say. The bottom chord of a truss is typically engineered to hold up the ceiling and support the designed snow load as part of the overall assembly. Same with stick framing. The ceiling joists are normally not properly sized for use as floor joists also. The fact that folks sometimes noncompliantly use these framing members as floor joists is none of my concern. If they're not sized for use as floor joists, they're not floor joists; they're ceiling joists.
 
??

??

and, since they are not "floor joists" 320.23 does not apply.... is that your take ????
 
mdshunk said:
The NEC should say "framing members" in place of "floor joists" if that's what they meant to say. The bottom chord of a truss is typically engineered to hold up the ceiling and support the designed snow load as part of the overall assembly. Same with stick framing. The ceiling joists are normally not properly sized for use as floor joists also. The fact that folks sometimes noncompliantly use these framing members as floor joists is none of my concern. If they're not sized for use as floor joists, they're not floor joists; they're ceiling joists.
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Marc
Maybe so. We should all remember that some of the requirements in the NEC have been around for awhile. Maybe with access to information, technology, and forums like this one, the wording in the NEC comes under more of a microscope.
If you believe the wording needs adjustment, then a proposal can kill two birds with one stone.
Provide a proposal - the CMP will either agree or disagree - either way their substantiation may help to clear up the concern for the existing wording/meaning.
 
Pierre C Belarge said:
Marc
Maybe so. We should all remember that some of the requirements in the NEC have been around for awhile. Maybe with access to information, technology, and forums like this one, the wording in the NEC comes under more of a microscope.
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Pierre I hate when you go there, if we find fault with the NEC you always tell us we are looking to hard.

The fact is a floor joist is a specific item, if they did not mean only floor joists they could have used many other different terms. To suggest that the CMP 'did not know better' in the past is not really fair.

Maybe they said exactly what they meant and it is the modern reader who is trying to change the intent.

JMO
 
iwire said:
Pierre I hate when you go there, if we find fault with the NEC you always tell us we are looking to hard.

The fact is a floor joist is a specific item, if they did not mean only floor joists they could have used many other different terms. To suggest that the CMP 'did not know better' in the past is not really fair.

Maybe they said exactly what they meant and it is the modern reader who is trying to change the intent.

JMO
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I am not saying that fault has been found at all.
What I am saying is that some of the code has been written before the style manual was in place, and before so many people have had the kind of access we now have available to us today. What this means is that someone could/should develop a proposal and help to get the wording closer to what was intended. (if the proposal is not accepted, the substantiation will possibly help to clear up some of the concerns)
Remember that CMP members are only human, and the process when this one code section was written may not have had the scrutiny applied that we see today.
 
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