When did ground wire start showing up in NM ?

[theoldwizard1]

I know this is probably dependent on what part of the country you live in and urban, suburban or rural. Looking for a ball park

Before WWII or after ?

My house was built in the early 50s and has the ground wire connected to the metallic box.

 

[Charles (in GA)]

My parents house was built in '56 and had Romex without a ground in it.

Charles

 

[matt151617]

Is it the old tar covered Romex? That stuff has a ground but a very small/thin one. My house was built in '51 and has some of that. It was apparently updated in the late 70s because it has lots of cream colored Romex and a Federal Pacific panel.

The 50s were a big transition period for houses. I had a few 2 prong outlets but they were all grounded. Also everything is gypsum board. Right around then is when plaster was replaced by drywall. They sure did know how to build solid houses then, everything is hardwood, and nice oak floors.

 

[theoldwizard1]

Is it the old tar covered Romex?

Yes.

The 50s were a big transition period for houses. I had a few 2 prong outlets but they were all grounded. Also everything is gypsum board.

My house was built in the early/mid 50s and has gypsum board and 3 wire NM, but no 3 prong outlets (until I swapped them).

My son's house was built mid/late 50s. Same situation.

My daughter's was built right after thew war, late 40s. Plaster and lath. I know all of the outlets are 2 prong. SIL says there is no ground wire, ow if he actually but I don't know if he actually opened a receptacle up and looked !

 

[Falcon67]

Our old house had a remodel in the 70s and they ran a bunch of 2 wire romex tied to the knob-and-tube. Some of it I left because it was stapled in walls that I could not easily fish.

 

[bigenos]

My house built in MD circa 1954 was plaster and gypsum. All 2-wire in unrenovated spaces. The house overall was built in a very "old" way based on the stone work and even the way the mortar was pointed.

 

[lakee911]

Type NM cable was first listed in the 1926 NEC. At the time it was a varnish or tar impregnated cloth covered cable. I believe that the grounding conductor was available earlier, but it was the 1962 NEC that mandated the EGC that the grounding conductor be used which popularized it. I'm betting it's tough to find it without the "+G" anymore.

Of course products phase in and out of existence and codes are adopted at various times so it's hard to nail a date. I'd bet that anytime in the 1950s to 1960s it started popping up. Around 1970 or so the reduced size EGC phased out...

 

[wyliesdiesels]

Our old house had a remodel in the 70s and they ran a bunch of 2 wire romex tied to the knob-and-tube. Some of it I left because it was stapled in walls that I could not easily fish.

Woa. Do u mean spliced into the K & T? If so and it was done incorrectly, it can be a fire hazard!