Mains wiring question (USA)

You might be able to use armored cable, the MX or whatever stuff. It's not very expensive.

John

You might ask him how sheet metal, which staples can penetrate, will protect the romex from nails. The real requirement may be that you will need to run it in steel conduit. Art

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uct

YOU USUALLY COVER ROMEX/UF AND OTHER NON-METALLIC CABLES AT THE BEAMS ONLY BASICALLY WHERE NAILS OR SCREWS MAY PENETRATE THEM WHEN ADDING DRYWALL OR WALL PANELS

YOU CAN GO TO A SCRAP METAL PLACE AND HAVE AS MANY SMALL PLATES AS YOU NEED CUT AND DRILLED OUT FOR YOU

EVEN ARMORED CABLE MAY BE SUBJECTED TO NAIL AND DRYWALL SCREW PENETRATION THEREFOR YOU MUST USE A STRONG [NAIL/SCEW DETERRING] PLATE METAL TO COVER BEAM/CABLE INTERSECTIONS

A CONSTRUCTION OR BUILDING MATERIALS PLACE MAY HAVE THEM REDY MADE

IAP

There is no logic to the declarations of building inspectors. He says if we choose to use romex (our option), we must cover it with metal strips wherever it is exposed.

Another option is to use armored (MX) cable or EMT conduit. Romex seems the simplest if we can find a simple metal strap to cover it.

Thanks.

On top of this flat-roofed building, picture a sea of plywood as far as the eye can see. Holes are drilled into the plywood where walls intersect the roof and romex is dropped into the walls. From this point to the distant location of the load (breaker) panel the romex is laid on the plywood and stapled down. Over this romex must be attached some kind of protection, declared by the local building inspector.

Thanks.

NG

he

THAT IS ODD I SUSPECT THE BUILDINGS INSPECTOR IS MISSING SOMETHING MAYBE HE IS A HACK CALL BLDGS DEPT. ASK FOR FIELD SUPERVISORS INPUT

IN ANY EVEN IF YOU CAN PROVE THE CABLES ARE NOT IN HARMS WAY YOU WILL SATISFY THE INSPECTORS REQUIREMENT YOU CAN ALSO TRY METAL RACEWAY (WIREMOLD) WHERE THE CABLE IS EXPOSED IT WILL MAKE YOU FEEL SAFER AS WELL BEST OF LUCK TO YOU

IAP

Ah, that clarifies the one question I had (thought you were talking SE, not branch circuits...)

I'd strongly recommend conduit (metalic) in this case. The sheet metal that would be required would be really hard to work with and form over the wires.

Be careful that whatever route you go, you have the inspector's approval of the materials before you begin, you don't want the problem of "Oh, that metal is not heavy enough" to rear its ugly head after you've completed the task! 3

For actual protection you want EMT or armored cable. While this roof is a foam roof, there's no telling what the next roofing job (quite possibly not done by you) will put over it...

To make the inspector happy you ask the inspector what the inspector wants to see. As described by you, a 50 foot roll (or as many as you need) of 4-6" aluminum flashing ("sheet metal") would apparently suit the inspector, while providing no protection to speak of (and the delightful possibility that you manage to staple into the cable while trying to staple the sheet metal over the cable). Of course, if you do that without getting a specific clearance from the inspector that this is what he wants to see, he might come back and indicate that he actually wanted galvanized steel, not aluminum, and make you rip it all up. At which point using EMT looks a whole lot easier, as well as more effective.

Where some types of wiring is near the edge of a stud and may be hit by a drywall screw the wiring needs to be protected by a 1/16" steel plate. I suggest you ask the inspector how heavy the "sheet metal" has to be. I don't know of a standard electrical item for the protection you need. I would ask at a company that makes ventilating ducts.

I know of metal plates made for protecting wiring in studs. They are a heavy gauge steel and have spikes that are hammered into the stud. I would rethink the use of EMT conduit as it will permit future wiring once the roofing is installed. It's also very cheap, all things considered.

tm

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The steel plates you describe are what I was referring to. They are not required if the wiring is rigid metal conduit, IMC, rigid nonmetallic conduit or EMT. Rigid PVC would be cheaper than EMT. If you are using conduit, you should be fishing wires, not using it to protect Romex. With either Romex or fished wire, too many wires in the conduit requires derating the wire amp rating. Empty spares for future use may be useful, as you probably said. You may want conduits for cable, phone, ....

This is an odd requirement and application. Run whatever you want to do past the inspector.

Seems like a nailing gun may penetrate conduit.

greg

EMT (electrical metallic tubing) is not considered protection for wiring, just tubing.

Use some square metal roof conduit designed for the job. It will probably stick up and not have anything stapled on top of it, Or put the wiring under the roof sheeting.

For actual protection you want EMT or armored cable. While this roof is a foam roof, there's no telling what the next roofing job (quite possibly not done by you) will put over it...

To make the inspector happy you ask the inspector what the inspector wants to see. As described by you, a 50 foot roll (or as many as you need) of 4-6" aluminum flashing ("sheet metal") would apparently suit the inspector, while providing no protection to speak of (and the delightful possibility that you manage to staple into the cable while trying to staple the sheet metal over the cable). Of course, if you do that without getting a specific clearance from the inspector that this is what he wants to see, he might come back and indicate that he actually wanted galvanized steel, not aluminum, and make you rip it all up. At which point using EMT looks a whole lot easier, as well as more effective.

You would buy the metal stock from the roofers. They use it to make up flashing and other transistions.

Charlie

The inspector is not crazy, just following the arcane rules like the good droid he is. You're looking for something like these:

They are typically used to protect cables and copper water pipes from drywall nails/screws. Probably find them at the local mega hardware store for not much money -- 19 cents each at the link above.

Like a few others, I'd vote for whatever type of conduit rocks your boat unless you're sure there will never again be the need for wiring mods.

Ken

SAY BOB E.

PLEEEEEEASE TELL US THAT BUILDING IS A PROP IN AN UP COMING MOVIE

PANELS AS FAR AS THE EYES CAN SEE ROOFTOP LOOSE WIRES RUNNING BARE OVER WOOD AND ALL THE INSPECTOR HAS TO SAY IS COVER THE CABLES? THAT IT IS NOT CUSTOMARY IN RESIDENTIAL NOR MILLENNIUM WIRING SCHEMES

IT HAS TO BE A PROP FOR SURE [:/ TWAHAHAHAHA SARCASTIC OBVIOS LAFF

I WOULDN'T STEP AN INCH INTO IT IF I WERE ANYHING NEAR HUMAN OR ANIMAL NOT WITHOUT FIRE PROTECTION

WITH THE AMPACITY, MELTING POINT AND A VARIABLE POWER SUPPLY THE ENTIRE WIRE/CABLE CAN BE RIGGED TO BURN THROUGH THE PANEL AND INTO THE ROOF IGNITING THE ENIYRE CEILING BENEATH IT SKILLED HANDS AND PROPER POWER SETTNGS AND IT WILL SET OFF A SHOW OF FLAMES AND SPARKS AT THE FLIP OF A SWITCH AND A TURN OF A KNOB [;o

CALIFORNIA HANH ? [;-)

IAP

The roofing contractor chimed in with an observation: conduit will result in the (poured? sprayed?) foam roof insulation making "mountain ranges" of foam which results in "pooling" when it rains, giving the roof the look of a lake district. Not a good thing. That's why low-profile romex (covered with protection) is the desired wiring method: good rain run-off.

The inspector said it needs to be the same gauge as the "nail plates" that someone here mentioned (1/16" steel plate). That's going to be some heavy metal...

Thanks.

in

oam

ake

THE INICIAL SMOKE WILL LET YOU KNOW IT'S WERKING I'D SET IT CONDUIT OR MENTAL RACEWAY [WIREMOLD BRAND]

I KNOW SOUNDS BORING NOW BUT JUST WAIT [:)]

IAP

SOME PUN INTENDED WITH THE ABOVE

REASONING: LAYED OUT ROMEX OVER A WOODEN ROOF THEN SNAKED THROUGH A HOLE INTO THE INNER WALLS OF THE STRUCTURE IS NOT A VERY SAFE WIRING PRACTICE

GET SPECIFICS FROM THE AUTHORITY HAVING JURISDICTION OR A PREFESSIONAL CONSULTANT VERSED IN THE NEC AND USA WIRE SAFETY CODES

THE INSPECTORS ASSESSMENT IS FLAWED ! ! !

THEY DO NOT CALL THAT MAINS WIRING IN THE US IF YOU ARE TALKING ABOUT WIRING THE SERVICE ENTRANCE ACROSS THE ROOF THEN DOWN TO THE DISTRIBUTION PANEL IN THE BUILDINGS INTERIOR IT IS BEST TO LENGTH IT OVER THE ROOF IN PROPER CONDUIT I WOULD USE AN INDUSTRIAL STRENGTH CHASE TO N FRO EACH PANEL

NOTHING MORE FOR NOW

BUT - SEEK HELP IF INSUFFICIENT