Old house wiring; time to replace?

Sarc · 09-18-2012, 04:58 PM

Went to replace the dimmer switch in the dining room tonight after it got the better end of a tennis ball (at 2, my son is apparently developing one hell of an arm). I take out the switch only to discover this, some of the old fabric covered wiring still in place (the house was built in 1895, most of it was rewired 10 years ago) .
What's the braintrust's opinion of the condition of this? I've always heard that if it's wet and oily, it's still ok. Well, I wouldn't necessarily consider it oily, but it's not dry and cracked either. Still seems pliable. Getting into the plaster ceiling is not high on my list of projects at the moment, but I don't want to stick my head in the sand about it either. If it should go, it will go. What say you guys?

recycled sixtie · recycled sixtie's Garage

We did the same thing a couple of years ago and had the basement wiring checked. Our house is about 55 years old. The electrician said it was good. I would recommend that u get a qualified electrician to check it out. As my daughter would say, why risk it for a biscuit.

HardDrive · 09-18-2012, 05:30 PM

If its for lighting, it might be fine. Is any of the wiring coming out of the box knob and tube?

djmcmath · 09-18-2012, 05:48 PM

I'm not an expert, but I am paranoid. I'm just finishing up the process of replacing all of the 1950's era wiring in my old house. A lot of my wires looked surprisingly similar to your picture. It scared me, so I replaced it.

That said, my house is not that big, and the job was huge. So don't undertake this lightly. A single light could consume several weekends, all by itself. Trust me. Oh, and the wires never go where you think they will, (crazed laugh).

But I sleep better at night, for what that's worth.

Good luck. Post pictures of your progress, I'm sure that others (like me) will be happy to help if we can.

Dan

notfarnow · 09-18-2012, 05:55 PM

knob and tube.

Insurance companies don't have much of a sense of humor about it anymore.

Zeke · 06:41 PM

@Sarc, the worst enemy of old wiring is disturbance. The wires you show are rather short and they don't like being folded up like modern wiring. Not much an electrician can do for you w/o breaking loose connections and testing for resistance. That's more disturbance.

Best thing to do is either go for broke and rip it all out, or gently pig tail what you have there with the same gauge wire. I do that with all old wiring so any further maintenance and repair does not yank on those wires.

I'm not advocating saving that wire. I'm only saying I could live with it.

look 171 · 09-18-2012, 06:26 PM

We have a bunch of older homes here in LA and I have had many wonderful times doing rehab work on them. electrical work is always involve in remodeling, always. Once I touch it, I am on the hook. I bet you if you go up in the attic and touch, and I mean touch or squeeze lightly, the fabric or the protective layer will fall right off leaving the bare wire expose. We did a renovation in a grand old house in Pasadena, a couple of years back. When we tore into it, there were bare wires exposed all over the place in bit and pieces and they were hot. You have my vote on changing it. If its within your budget, try and run the wires through conduit instead of Romex. My house is built in 1950. A few years ago, all the electrical were upgraded or changed. No romex there.

HardDrive · 09-18-2012, 06:45 PM

I think the dangers of knob and tube are overrated as long as the KnB has not been compromised in some way. I did a huge renovation a couple years ago, and I left some of the original work in place.

look 171 · 09-18-2012, 06:49 PM

Quote:

Originally Posted by HardDrive

I think the dangers of knob and tube are overrated as long as the KnB has not been compromised in some way. I did a huge renovation a couple years ago, and I left some of the original work in place.

My question is why? You already had it all torn apart. Like anything else, there is a time limit, even wires. That's where I come and do a lot of beating over my client's head with a piece of 2x4. Sometimes after long chats over the very subject, they usually cave. I am not trying to sell them but they need to know how to spend their money wisely.

Zeke · 09-18-2012, 07:10 PM

How long does a copper roof last? Old wiring gets brittle near a ceiling light that was designed for a 60w lamp and people use the old 100w. Other than that, it's not a problem left the way it was installed, i.e., no insulation covering it and no disturbance. If unsure, yank it out.

look 171 · 09-18-2012, 07:18 PM

Quote:

Originally Posted by Zeke

How long does a copper roof last? Old wiring gets brittle near a ceiling light that was designed for a 60w lamp and people use the old 100w. Other than that, it's not a problem left the way it was installed, i.e., no insulation covering it and no disturbance. If unsure, yank it out.

Tell that to the insurance company. Once you have the place open, it should be a no brainer. Copper will last forever, but the sheathing doesn't last that long. I have seem modern THNN jacket go brittle when I tear into some of these homes. Those are newer wires. I am questioning how long with the jacket on the Romex wires last. Once they go, you are done. Time to rip out all the walls and start all over. That patching is going to be a big bill. Hopefully they will do it right so its seamless. There will be a lot of piss off people out there soon, very soon.

HardDrive · 09-18-2012, 07:34 PM

Quote:

Originally Posted by look 171

My question is why?

It would have meant disturbing a lot of plaster, for a few circuits that handle lighting.

look 171 · 09-18-2012, 07:41 PM

Quote:

Originally Posted by HardDrive

It would have meant disturbing a lot of plaster, for a few circuits that handle lighting.

Could they have gotten to it up in the attic with minimal amount of patching. LLighting sound like it should be OK. Just don't mess with them.

Sarc · 05:58 AM

Thanks guys for the input. I've got a close friend (an electrician) coming over this weekend to take a closer look and give me his .02. Kind of leaning towards ripping it all out. In the meantime, I'm going to try to take a peek from above through a second floor closet that sits right above the dining room..

Great to hear about the longevity of the Romex!....the house is full of it from the previous rewiring effort.

Zeke · 09-19-2012, 07:26 AM

I'll have to add in that old houses that have knob a tube weren't ready for microwave ovens and plug strips with TV's and all the peripherals. Kitchens and baths should be rewired along with outlets for heavy draw. So, really, look 171 is right. I just tend to be conservative.

I don't want to give bad advice. Now if we were talking about aluminum wiring, I'd be more afraid. That needs to be pigtailed with copper and anti-oxidant paste.

Wiring should only be put up to the task of what is was originally designed and installed to do. In my old house it runs everywhere, but it only runs lights. The kitchen and baths have been rewired and there are a couple of 20a outlets in each bedroom for TVs, etc.

Heat is the main deteriorating factor and oxidation is 2nd. Be sure to scrape the bare ends of old wiring when nutting up to another.

porwolf · 09-19-2012, 08:46 AM

Quote:

Originally Posted by Zeke

@Sarc, the worst enemy of old wiring is disturbance. The wires you show are rather short and they don't like being folded up like modern wiring. Not much an electrician can do for you w/o breaking loose connections and testing for resistance. That's more disturbance.

Best thing to do is either go for broke and rip it all out, or gently pig tail what you have there with the same gauge wire. I do that with all old wiring so any further maintenance and repair does not yank on those wires.

I'm not advocating saving that wire. I'm only saying I could live with it.

I had the same experience with the same kind of stiff canvas covered wiring. On occasion the whole insulation crumpled away especially at the entry point into the wiring boxes. I slipped two layers of heat shrink tubing over the remaining insulation as far into the conduits as possible. This created new insulation right at the most critical point of entry and inside the wiring box for the lenght of the wires. It looked like the wiring inside the original metal conduits, being undisturbed, still did it's job.

look 171 · 09-19-2012, 01:32 PM

Quote:

Originally Posted by porwolf

I had the same experience with the same kind of stiff canvas covered wiring. On occasion the whole insulation crumpled away especially at the entry point into the wiring boxes. I slipped two layers of heat shrink tubing over the remaining insulation as far into the conduits as possible. This created new insulation right at the most critical point of entry and inside the wiring box for the lenght of the wires. It looked like the wiring inside the original metal conduits, being undisturbed, still did it's job.

Some things just doesn't make sense but what you did is perfectly fine and it actually protects the wires. But, the big but, is the insurance going to accept it should something goes wrong and they discover what you did up there? That, my friend, put the fear in me.

azasadny · azasadny's Garage

When we renovated our house that was built in 1936, we replaced all of the wiring. It looked a lot like yours. It was harder to rip out the old stuff than to run the new Romex, and I'm glad we did it!

notfarnow · 09-19-2012, 05:54 PM

Quote:

Originally Posted by Zeke

I'll have to add in that old houses that have knob a tube weren't ready for microwave ovens and plug strips with TV's and all the peripherals. Kitchens and baths should be rewired along with outlets for heavy draw. So, really, look 171 is right. I just tend to be conservative.

I don't want to give bad advice. Now if we were talking about aluminum wiring, I'd be more afraid. That needs to be pigtailed with copper and anti-oxidant paste.

Lots of older housing stock where I live & sell real estate, and old wiring is becoming more & more of an issue.

In the past month I've had to explain to two clients that their homes have wiring that is uninsurable. It's hard for them to grasp, when they have lived with it for decades without issues, and in one case they were under the impression that their knob + tube was "completely updated" because it was all GFCI protected (that was typically the insuarance co requirement 10+ yrs ago). Now the house has to be rewired to the tune of 15k (plus drywall, paint) before a buyer can get insurance. Sure is fun to deliver THAT news.

Even 1950's ungrounded romex is becoming an issue, and will likely be lumped in with knob + tube in the next few years.

Aluminum? Some insurance co's won't touch it at all anymore, even if it's been properly pigtailed to copper by a licensed electrician.

Safe or not, I'd swap out any outdated wiring while you've got the chance.