Another NM in attics question...

[James L]

Do you guys really need an article 100 definition to tell you that a cable draped across ceiling joists without staples is not secured?

I don't know anything about draping.
But if that cable is running perpendicular to the joists, and it is stapled on each end, it's just as secure as cable stackers holding the cables running down a stud.

That's why a definition is probably in order. It's inconsistent

 

[jaggedben]

I don't know anything about draping.
But if that cable is running perpendicular to the joists, and it is stapled on each end, it's just as secure as cable stackers holding the cables running down a stud.

Seriously, no it's not. It's supported but not secured per code, unless the run is less than 4ft and it's secured at both ends. Depending on the length of the run, the slack could easily allow it to be pulled back and forth up to a few feet.

Perhaps it makes no safety difference in a typical attic, but it doesn't meet the letter of the code.

 

[James L]

Seriously, no it's not. It's supported but not secured per code, unless the run is less than 4ft and it's secured at both ends. Depending on the length of the run, the slack could easily allow it to be pulled back and forth up to a few feet.

Perhaps it makes no safety difference in a typical attic, but it doesn't meet the letter of the code.

Code doesn't define "secure", so how can you even say such a thing that is not secured per code, and it doesn't meet the letter of the code?

There simply isn't any letter of the code regarding that word

 

[suemarkp]

If you've done nothing but set it on a joist on in the crotch of the truss, then it isn't secured. If you attached the cable to something every 4 feet then it is secured. You can argue that an NM cable stacker is crappy securing, but gravity and air are not securing. A staple is good securing.

 

[James L]

If you've done nothing but set it on a joist on in the crotch of the truss, then it isn't secured. If you attached the cable to something every 4 feet then it is secured. You can argue that an NM cable stacker is crappy securing, but gravity and air are not securing. A staple is good securing.

It doesn't even have to be secured in an attic. There isn't anything related to an attic installation of NM cable that requires securing if it's on top of the joists.

There are only two requirements:
334.23 which specifically states only one requirement for installation of NM in an attic - that it must comply with the requirements for 32.23

320.23 regards AC cable, and specifically mentions the requirements for attics, and specifically mentions cable run on top of joists.

ZERO mentions of securing the cable.

 

[jaggedben]

Code doesn't define "secure", so how can you even say such a thing that is not secured per code, and it doesn't meet the letter of the code?

There simply isn't any letter of the code regarding that word

Then you use the dictionary.

There are lots commonplace English terms that the code uses without special definitions. If there were some vagueness as to how the commonplace meaning affected interpretation of the code requirement, perhaps you'd have a point. But there isn't in this case. You're stretching that argument too far.

 

[suemarkp]

It doesn't even have to be secured in an attic. There isn't anything related to an attic installation of NM cable that requires securing if it's on top of the joists.

There are only two requirements:
334.23 which specifically states only one requirement for installation of NM in an attic - that it must comply with the requirements for 32.23

320.23 regards AC cable, and specifically mentions the requirements for attics, and specifically mentions cable run on top of joists.

ZERO mentions of securing the cable.

See that one word "also" in 334.23? That means it is an additional requirement for attics, not that you can throw out all the other ones because its an attic. 334.30 says you need to secure and support every 4.5 feet.

An interesting question would be if you were installing AC cable in an attic, does 320.34 override all the other install requirements. I don't think it does. How effective would a guard strip be if it only has to be the height of the cable and the cable isn't secured. You could pull it right out of the guards. I'd argue even in this case that 320.23 is an additional install requirement, not the only one. Do you think you can ignore 320.24 in an attic (bending radius limitation) as that seems like an install requirement to me and shouldn't be over ridden by 320.23?

 

[James L]

See that one word "also" in 334.23?

as a matter of fact, no. I never saw that word also until you just pointed it out

Dang, there goes that argument.

 

[LPS]

Thanks for all the feedback. Sounds like the people that wrote the handbook wasn’t crazy after all. I wonder if the code making panel has ever considered revising the wording to make it more clear. Or perhaps because it doesn’t seem to be much of safety consern leaving it vague and just not talking about it is better. Lol