I was inspecting a steel frame home. While in the attic space i noticed the electrical conductors for the house lying along the edges of the steel trusses.
My thoughts were that if one was in the attic and stepped on a wire just right and sliced it it would charge the whole attic.
When running wires in attics with steel frame trusses is there anything required to protect conductors from getting damaged/cut
Hi Matthew,
Yes those conductors should be protected from any potential damage with either, bushings, conduit or a nailer attached to the steelwork. As you have stated this setup has the ability to energize the framing.
Regards
Gerry
Thanks Gerry
First off, metal framing should be bonded. This will prevent any chance of “energizing” it.
Second, yes, if passing through holes in the framing there must be protection. If the cables are just laying across the outside of the framing, and they are well away from the scuttle hole, and clear of being stepped on, there is no protection required.
Is the attic designed to be commonly accessed?
tom
Got any pictures? I’d like to see what the attic of a steel framed dwelling might look like.
I do not have pictures, however there were wires at the scuttle entrance and around the air handler unit.
I was also given this information:
250.104 Bonding of Piping Systems and Exposed Structural Steel.
Thank you all for your replies.
Metal framing is an excellent conductor of electricity. Therefore extra caution shall be observed too avoid contacting energized electrical conductors (wiring) when entering or working in the subject property attic space for equipment servicing or other purposes. Never install service or storage platform materials atop the electrical wiring.
If anyone is dumb enough to directly contact, step on or stand on wiring, no matter the location they may deserve the consequences.
Thinning of the gene pool is necessary in certain cases.:mrgreen:
Found this: http://www.mikeholt.com/videodisplaynew.php?pageid=4328
250.104© There is a comment about metal studs, and requirements.
tom
Florida has added bonding steel studs to the building code but the NEC does not require it.
I can see where it would be likely that an inspector would require all RX in the attic of a steel framed building to be secured. They are pretty conscientous in this county about making sure ALL wiring in the attic is secured before the ceiling drywall goes up. If you see loose RX it was put there after the FEPAC. Steel trussers are still pretty rare here so the wiring is going to be laying on wood truss chords. Where it comes through the steel wall members it is required to be in grommets and also draft stopped.
Steel studs are not “structural” steel. They have virtually no load bearing capability in the guage you see in residential construction. A load beraring wall will still be wood.
Thomas,
very helpful video.
Thanks everyone for your input.
Check IRC R603
I think that disputes your statement and the home in my photos complies, no wood except for blocking or backing.
Hello Greg,
I looked at the home under construction next to the one i inspected. It was steel frame all the way around, including all interior walls. The only wood was the roof sheathing.
[quote=mhawley]
Here is a intresting video/story
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The root cause seems the violation of routing wires < 1.25" from all nailing/fastening surfaces. The screw was only 1 inch long.
Very sad. I think situations like this reinforces the idea of AFCI’s for all branch circuits. The internal lowered (50ma I believe) ground fault might have even tripped one fore arcing occurred. Might have saved a life.
Barry, we don’t see much of that here. They just use the thin guage studs for partition walls. I have seen them use what you are showing in commercial.
I saw one house with steel roof framing but it was a “one shot” spec house.
Exterior walls are virtually always concrete block and stucco. It is easier to get to the wind code that way.
Does Oklahoma specifically require bonding of the framing?
Greg,
I don’t have a clue what they do in Oklahoma. I sure hope they would.
The house in my photos and I both reside in Texas and yes they are bonded on all the one’s I’ve looked at.
In case you were mislead Texas ceded Oklahoma many years ago.
https://scandocs.glo.state.tx.us/arcmaps/images/2114.jpg
Sorry my fault. One of those Red River errors.
All of my “Adair” relatives live in Oklahoma. My fingers started before my brain was in gear.
Stuff happens but an error like that in these parts is punishable by hangin’ as you well know. evil grin
Greg,
I may have to stand corrected. Upon further investigation and you getting me to question this I may have my interpretation wrong but I would still call them on it. Maybe this will be addressed in '08 NEC. Good work my friend!
Here’s a news letter with diagram. scroll down http://www.mikeholt.com/newsletters.php?action=display&letterID=191
NEC DOES NOT require structural studs or sheet metal framing members bonding but it is a “good idea” I guess the sparkies around here have common sense and know this and I look for the bond attachment anyway.
It has yet become a point of contention and most would cave once logic and the code section was produced, not having the rest of the commentary.
Another example of the CODE being the least you can get away with.
I’ll get a photo of the bond connector next time I’m out there, but all the phase houses I had contracted are finished now. I should be setting up 1 year warranty appointments this summer.