What is the name of the old Romex type wire? Seems similar to modern Romex, but is wrapped in a woven paper or fiber and painted silver. I think I’ve heard it called silver back, but was wondering its actual name. What years would it have been used in residential construction?
Old Romex type wire.
- Thread starter rrwwff
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Rusted Nut
Well-known member
I dont know it’s name, but I have seen it in homes built in the fifties and sixties, but not in anything built in the seventies. The outer silver covering can get pretty brittle over time.
Debcrow
Well-known member
Pretty much used from the 1950's and just into the 1970's. Some people think the outer cloth covering is asbestos, but it is mostly oil impregnated cloth, like burlap. Tends to get frayed/brittle after so many years. I always replace it when I find it. However, if it is not moved or disturbed it will still work in most cases. But it is a hazard, especially fire, so removed and replace if you can. I believe it was called NWC.
I believe this house was built in the late 50’s. Yes, the outer jacket will just crumble away when trying to strip it back to get to the insulated wires.
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cmandp
Well-known member
It is still classified at 'NM' cable as in non metallic. But being older it will not have the same temperature rating as modern NM-b. Also materials available back then were different
Romex is a brand name of NM-b from Southwire. There were many brands of NM back then. Colonial flex is one I remember.
Really old NM cable is rubber isolated with fabric covering individual conductors with a fabric sheathing.
Romex is a brand name of NM-b from Southwire. There were many brands of NM back then. Colonial flex is one I remember.
Really old NM cable is rubber isolated with fabric covering individual conductors with a fabric sheathing.
klassenl
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Loomex was what it was called in some places. "Loomex" was probably a brand name.
wyliesdiesels
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wyliesdiesels
Well-known member
i posted my reply then saw you beat me to it.
Romex® was made in NM, & NM-B, although Romex was made by General Cable when NM was being produced.
rancherbill
Well-known member
Here is the list of all the OLD WIRE BRAND NAMES AND MANUFACTURERS it is written by a canadian guy and show Canadian and US name and companies.
https://inspectapedia.com/electric/Old-Fabric-Insulated-Electrical-Wire-ID.php
https://inspectapedia.com/electric/Old-Fabric-Insulated-Electrical-Wire-ID.php
wyliesdiesels
Well-known member
Cool that would make a great addition to the electrical FAQs sticky
b-boy
Well-known member
I'm remodeling my attic. This type of wire was run everywhere during a remodel years ago. The wire has not held up well. Being in a hot attic all summer did a number on the sheathing. It just falls apart when you touch it or bend it. Luckily it's all getting tossed.
Now I can set an approximate date to when the remodel probably took place.
They used this and some stuff that looks like pre-finished drywall. It has a wood grain pattern on it. I've never seen anything like it before.
Now I can set an approximate date to when the remodel probably took place.
They used this and some stuff that looks like pre-finished drywall. It has a wood grain pattern on it. I've never seen anything like it before.
SlappyWhite
Well-known member
In Canada we typically refer to it as NMD60 (Non-Metallic Dry 60°C rated), the newer stuff is NMD90 (90°C rated). The term NMD60 may be a retroactive one, that I cannot say. There may be some of the older style that was higher than 60°C but we pretty much assume it is all 60....
As mentioned in the K&T thread about ceiling fixtures. You can find heat deteriorated conductor insulation with this older wire in the box in areas with surface mount light fixtures (not hanging) that were overloaded with multiple high wattage incandescent bulbs over a few decades... (kitchen typically being the worst).
As mentioned in the K&T thread about ceiling fixtures. You can find heat deteriorated conductor insulation with this older wire in the box in areas with surface mount light fixtures (not hanging) that were overloaded with multiple high wattage incandescent bulbs over a few decades... (kitchen typically being the worst).
RPH
Well-known member
The question I would have, is a what point does the spool of wire that was unused and sat for X amount of time. Like decades or just years.
Does it age out or is coded out of use? Besides scrap value is there any electrical use in today’s codes?
Any known prohibitions on its current use?
Does it age out or is coded out of use? Besides scrap value is there any electrical use in today’s codes?
Any known prohibitions on its current use?
If the jacket is not brittle from heat damage, and contains the bare bond wire (although it might be #16) I would consider using it in a home of a vintage that already contains a bunch of it.
It may in fact be substandard by current Code regardless, if that bond wire isnt #14.
Beyond that, get new cable.
It may in fact be substandard by current Code regardless, if that bond wire isnt #14.
Beyond that, get new cable.
alfredeneuman
Well-known member
It may in fact be substandard by current Code regardless, if that bond wire isn't the proper
size for the circuit.
#14 is just allowed for 15A circuits in the US
rancherbill
Well-known member
Most likely it will be coded out. I had a roll 75m of ???-60 14/2 underground wire I wanted to use for underground stuff when building house. The electrician flipped out that the current code called for NMWU-90. The stuff I had was real underground wire but the sheath was not rated at 90. I gave it to a buddy that was building a barn for his menagerie with the CLEAR STATEMENT that if an inspector saw it, he would have to claim that the wiring was done years ago.
Code gets upgraded as technology increase. The sheathing spec increases because they can increase.
The NEC requires NM cable to be rated for 90°C, if is older material is marked as "NM" and not "NM-B" it cannot be used because cable marked as NM is 60°C, the spool/roll is scrap metal. Product that age is nearly 40 years old since it changed around 1984-85. That is why a old spool of aluminum NM cable can't be used even though the NEC never has prohibited it's use.
RPH
Well-known member
Ok, guys all excellent answers to the question. Thanks for the replies and education on nm wiring.
Another question on wires, is there an age limit on then / thwn wire? Or does it come down to temperature limitations again.
Another question on wires, is there an age limit on then / thwn wire? Or does it come down to temperature limitations again.
SlappyWhite
Well-known member
alfredeneuman
Well-known member
The first time I used NM-B was in '86. I was amazed by how small it was.On a house from the '50s we were doing a rewire as part of a remodel, replacing silver finished fabric "Paranite" brand NM. The old cable's jacket would fall apart if it was bent even slightly.
By the end of the job we were calling it Parasite cable
Crumbling cable jacket has most certainly been overheated - probably from ambient temps. I have plenty of the tar/burlap jacket cable that still seems 'good-as-new'.
IMHO, it doesn't matter when a house is full of this old 'sub-standard' cable anyway. #14 and 15A circuits is about all you find in older homes this side of the border.
alfredeneuman
Well-known member
How old does the house have to be to be considered sub-standard?
(The mid 50s house I'm referring to had an electric cooktop, oven, water heater, and dryer all of which have a larger than 15A circuit. All the receptacles were on 20A breakers). I consider it sub-standard
Can't speak for the house - I mean the electrical installation. Every Code revision makes some old work out there sub-standard.
Yes, I'm poking fun at the sometimes-silly regulations. Car guys are rather excited to snag a NOS 50yo part for their 50yo car.