Knob and Tube - home inspection

[Jerramundi]

I would also add that nail plates are not required for EMT through studs.

It would seem you are correct. Maybe I just glossed over the exceptions in 300.4. I've also had inspectors ask me to do nail plates on my EMT, so it just became habit.

Either way, I'll still continue to use them. Cheap, quick, and a great added level of protection. It really comes down to... would you rather install a $0.10 nail plate with a couple quick taps of the hammer? Or have to open the wall after everything is finished, fix damaged conduit, and re-pull your wire? For the cost, I think the prior is obvious.

 

[kwired]

emt and nail plates??? ~RJ~

Not code required but may be justification in some cases. I remember one time having a short ciruit /ground fault issue to figure out. Turned out old light outlet box had luminaire removed and surface linear fluorescent installed as a replacement luminaire. Mounting screws were drywall screws, one went right into EMT connected to the outlet box and must have nicked conductor, but took time (maybe a 3-5 years since light was installed) before it developed the fault.

 

[infinity]

With metal studs and MC cable no protection is required when running through holes in the studs even if the stud holes are less than 1.25" from the edge. 1 5/8" studs are used all of the time with MC cable through the holes in the studs and no protection.

You sure? I thought they were if it's a certain distance from the edge?

Yes. Find me a code section that says otherwise.

 

[hbiss]

You can't prove that by me, lol.
I have a guy that does some framing and sheet rock for me, he can hit it, not only hit it but drive right into it. He hit free floating mc in a wall space that lower studs didn't aline with upper studs, mc floating across a 16" space, hit it dead center of space and of the mc, right into a spiral groove driving screw in and blowing the breaker. I too always thought the cables would just move. That became a 2 junction box repair.

You can't fix stupid, there's only so much you can do. Why was this guy using such long screws?

As to EMT and nail plates: what is the wall thickness of EMT and what is the thickness of nail plates? Pretty much the same?

-Hal

 

[Jerramundi]

Yes. Find me a code section that says otherwise.

Well. I was responding to your point about EMT, which you seem to be correct about.
Not sure where I got the idea from regarding nail plates and EMT. It was either from another building code or I must have glossed over the exceptions in 300.4.

But now you've thrown MC Cable into the mix. The ONLY exceptions I see in 300.4 are for RMC, IMC, and EMT.

 

[infinity]

Well. I was responding to your point about EMT, which you seem to be correct about.
Not sure where I got the idea from regarding nail plates and EMT. It was either from another building code or I must have glossed over the exceptions in 300.4.

But now you've thrown MC Cable into the mix. The ONLY exceptions I see in 300.4 are for RMC, IMC, and EMT.

Sorry you quoted my entire post so I wasn't sure which part you were referring to. So for EMT in either bored holes or notches in wood, 300.4(A)(1)Ex1 or 300.4(A)(2)Ex would both allow the tubing to be installed without additional protection.

Regarding MC cable were talking about metal studs not bored holes in wood. You missed the metal stud part.

 

[Fred B]

You can't fix stupid, there's only so much you can do. Why was this guy using such long screws?
.......
-Hal

He wasn't using a long screw, he hit it just right that the tip of the screw caught the spiral of the mc and it actually pulled the mc onto the screw, a fraction of a fraction of an inch one way or other it would have pushed the mc aside. I think he's the only one that could hit that 1 in a million position on that mc. On top of it was the fact that it was not a line we were working on or installed, that had been there at least 15 yrs. Same guy has made a couple of other 1 in a million hits in other material. He now takes a lot of flack anytime something odd happens and he's been on the job, all in good funning.