I'm thinking of making an offer on an old home from 1954. It's got the old style, no ground plugs and a very old looking electrical panel. The house is 1200 sq feet. If you had to come up with a number, how much do you think it would cost to replace all the wiring and get this thing up to date?

It also have a weird situation where it basically has 2 front doors because of an addition. The original front door now leads to the master bedroom, and I would want to fill it in with cinder blocks/brick.

2 seems very DIY able, but not sure about number 1. Any idea how much these kinda things would cost to do?

don't know about where you are… but here, the major electric co. will do an estimate for free

Depends on how its built. You mention cinder block?

Kenny_McCormic wrote: Depends on how its built. You mention cinder block?

This. Wall construction will greatly affect a re-wiring estimate. It is a HELL of a lot easier/faster to rewire a house with bare studs than it is to rewire with existing walls. Even more so if the walls are plaster (common in old houses). Good basement access? How many floors? Good attic access?

Actual materials aren't too bad, but I can say from recent experience you will need MUCH more 14/2 and 12/2 than you think you will. I went through about 1000' of wire for the ex-g/f's second floor addition and living room/kitchen remodel. Of course, I would have used half as much if she didn't want what felt like a bajillion (over 50) recessed lights in the ceilings of both floors. Plus hard-wired smoke detectors throughout the house (boy, that was fun...).

Branch wiring (from the panel circuit breakers to the various devices) is pretty easy for a DIY'er. A Mains panel replacement, however, will probably need to be done by a licensed electrician. At a minimum, it will require a permit and an electrical inspection.

There are a couple of ways to DIY this,

1. Install the panel and connect all of the new wiring to it and then swap over the service to the new panel when done.

2. Install the new panel and back-feed the old panel, swapping over circuits as you go.

Personally, I'd do the latter since it would keep more things operational during the work, but I also have no qualms about working in a live panel. (there were a few times when I scared myself with how comfortable I am doing it...) Many are not so comfortable.

(disclaimer: I'm not an electrician, but I design building electrical systems for a living, so I'm more comfortable than many with electricity. I design a lot of renovation work, although mainly for office/industrial applications, but the principles are essentially the same for residential work)

we burned through 500 feet of 14/2, 400 feet of 12/2 and about 250 feet of 14/3 to totally rewire an 1100 square foot house a few weeks ago. we had an easy run straight up off the panel in the laundry room and used the 2nd floor joist bays as chases so not much waste going around things. just to give an idea of materials needed. plus a bunch of old work boxes and all new outlets and switches. try and keep as many standard 19 cent switches as possible, once you get into 3 ways or double switches the price jumps up a ton.

Yeah, rewiring old cinder block construction is probably going to be on the pricey side. If you are lucky, the wiring will be overhead with 'drops' to each switch and outlet, that's not terribly hard to redo. If you aren't lucky, there won't be 'drops' and rewiring will be a royal PITA. In fact, this very scenario is one reason I backed off buying a '50's house here. It was stud wall, to make it truly liveable would have meant tearing out all the lath & plaster, running all new wiring, adding insulation, replacing the pipes with PVC or similar then having it all Sheetrocked and painted. The money aspect just did not work out.

About plumbing, here's something to consider: until the early 1970's sewer plumbing was done with galvanized steel. I have a friend with a house built in 1969, hers has galvanized and it's collapsing under a slab. You don't even want to know the estimates to fix this. If this house you are looking at is crawl space it wouldn't be as bad but still not cheap/easy.

The house I'm currently in had a sewage line collapse. Luckily, my dad was a plumber at the time, so not only did he have the know-how, he had the tools. Very large portions of the slab had to be removed in order to replace the pipe. If it would have been done by a contractor, I couldn't imagine how expensive that repair would have been.

I'll throw my $.02 in. You can keep the change.

10k if sheetrock wall. 16k+ if plaster. I've done 2 block home/sheetrock re-wires with 3ways, decor outlets, etc. They were both under 10k and 1650 and 1850 sqft homes, but I hunted deals on wire. I've also worked on older homes in New England and the plaster/lathe will be a pita.

I live in an old house with old and new electrical (addition has new stuff). Honestly, I would walk away. Find a newer old house.

[Threadjack]

I have a 1937 house with a similar need to rewire. It is wired 90% with MC and a few new circuits have been added with romex over the years. Every time I open a box I find this rotten cloth insulation on the conductors that falls apart when you breathe on it.

Couldn't a person just pull new wire through the MC and avoid all the drywall headaches?

[/threadjack]

(P.S. for those of you who don't know, MC is this stuff, but mine doesn't have the typical plastic insulation on the conductors, it has the cloth.)

Why would you want to rewire the whole place? Update the service to 100 amp if it isn't already, put in a new breaker panel and call it a day. 1954 isn't that old.

In reply to curtis73:

The newer armored cable is built differently, has a wire through the crimp to keep the jacket from turning into a big resistor should it be called upon as a ground conductor. So IDK how that would work into codes. OTOH that old cable is huge for the relatively thickly insulted wires, so pulling through 3 modern 12 gauge wires would be easy.

I live in a 1930 luxury apartment wired that way, found that all the outlets still had a decent ground connection through the BX cable, so screwing down one of those 2-3 prong adapters with the outlet cover screw will give you a good enough 3 prong outlet. After discovering that 3 out of 6 edison base fuses were 20-30 amps instead of 15(yes, I looked for coins under the 15s).

In reply to curtis73: nope your place is wired with bx cable and it is an assembly even if you could physically pull out the old wires it wouldn't be legal.

Hmm, I wonder if you could pull the much skinnier 14-3 modern "BX" through the older bigger BX. Maybe commercial wiring is different but the BX on the lighting (as seen from a trap door in the floor) in my apt building is at least 1" OD. Or just pull romex through it if it will fit.

Enyar wrote: #2 seems very DIY able, but not sure about number 1.

You have answered your own question.

If you are not sure about electric wiring, you are not qualified to DIY.

As others have noted, price will vary greatly depending on geographic location and construction type.

Several years ago I lived in a house built in 1947. It had a 100 amp panel, at some point the original fuse type panel had been replaced with a breaker panel of the same rating. There are a couple of problems with this: if upgrading to a more modern heat pump etc the breaker box would not be capable of running it along with a 240V water heater and clothes dryer, it would be necessary to upgrade the panel.

Also, the limited number of breakers meant that multiple rooms were on the same breakers, if a breaker tripped half the house would go dark.

Then there was the back porch which had been enclosed and turned into a laundry room with some really bodged wiring. That part of the house scared me.

I have also run across 'upgraded' wiring where the white and black were reversed. Not a nice thing to find. I also nearly got electrocuted because someone had a thermostat transformer and the motor it controlled on separate breaker circuits. I can still see the shower of sparks.

Kenny_McCormic wrote: In reply to curtis73: The newer armored cable is built differently, has a wire through the crimp to keep the jacket from turning into a big resistor should it be called upon as a ground conductor. So IDK how that would work into codes. OTOH that old cable is huge for the relatively thickly insulted wires, so pulling through 3 modern 12 gauge wires would be easy. I live in a 1930 luxury apartment wired that way, found that all the outlets still had a decent ground connection through the BX cable, so screwing down one of those 2-3 prong adapters with the outlet cover screw will give you a good enough 3 prong outlet. After discovering that 3 out of 6 edison base fuses were 20-30 amps instead of 15(yes, I looked for coins under the 15s).

I just replaced all my 2-prong outlets with three-prong and a ground wire to the clamp screw in the box. I don't know how much load the jackets will take, but there is good continuity to the ground bar in the breaker box.

I'm just freaked out about the crappy insulation.

In reply to curtis73:

That's the trouble, will the jacket flow 15 amps well enough to trip the breaker/fuse, or will it turn into a big coiled heating element?

curtis73 wrote: I just replaced all my 2-prong outlets with three-prong and a ground wire to the clamp screw in the box. I don't know how much load the jackets will take, but there is good continuity to the ground bar in the breaker box. I'm just freaked out about the crappy insulation.

That is an illegal installation.

You can't switch 3 prong outlets for 2 prong when there is no ground conductor wire. The MC (metal cladding) sheathing does not count as a ground.

No it doesn't. There is no local code.

The code is the NEC- the National Electric Code.

Some local officials may enforce it better than others, but there is no local electric code.

The NEC prohibits screwing MC armored cable (or conduit) to the box for a ground because of the potential for the screw to be loosened or disconnected, which creates a faulty ground. As Kenny_McCormick noted, the entire system can become a heating element instead of a ground. Good opportunity for fire.

In reply to Datsun1500:

No problem.

That was the law- here's my opinion...

The metal sheathing can function as a decent ground. Grounding is grounding, and it is only important when something goes bad anyway (or with sensitive electronic equipment)...

...HOWEVER, there is a good possibility it will NOT maintain a good ground for the usable life of the electrical system. It is therefore BAD practice, which I do not do.

I do not expect home occupants (or potential future occupants) to be electricians, know anything about electricity, or in any way act responsibly. I do my best to idiot-proof my work, because I consider it important that my work never put anyone at risk due to negligence on my part, now or in the future.

Yikes, very scary stuff. Fortunately and unfortunately, the house is block construction on a slab (no access underneath). On top of that, the living room is a converted sun room, which means all four walls are block construction and the kitchen shares one of these walls.

It's too bad really. This house has all the good bones. New AC, new roof, block construction and an upcoming neighborhood. The kitchen and bathroom remodel sounds like a good learning experience and a way to add value...the wiring sounds like a nightmare.

In reply to Enyar:

Well, it depends - do you need to be able to live in the house while working on it? If so, then yes - rewiring would be a nightmare (I need/want to rewire my house and I really wish I could move out while I do it). However, if you can essentially gut the walls, it would be a relatively straight forward job. Without more detailed specifics on the house layout, panel location, etc, it's difficult to say more.

The nice thing about the NEC is it basically says what you can and can't do.

For curtis - while in theory you could pull new wire through the existing BX, the likelihood of the new wire insulation getting cut during the pulling operation would be extremely high. I know where you're coming from. I pulled out a lot of that wire with deteriorating cloth insulation when working on the ex-g/f's house.

The most important thing about wiring is to get whatever you do checked. Like I said, I play with this stuff every day, but when I wired her kitchen I ran 14/2 (15A) for the receptacles when it should have been 12/2 (20A). A stupid, brain-fart mistake and she was pissed at me, but as far as I was concerned it was an easy fix. If the inspector had issues with some of the more complicated stuff I did (like the sub-panel installation on the second floor), the whole project could have turned into even more of a nightmare. Fortunately, he didn't go into the basement where nearly all of the existing wiring was against code (romex stapled to the bottom of the joists).

Ian F wrote: In reply to Enyar: Well, it depends - do you need to be able to live in the house while working on it? If so, then yes - rewiring would be a nightmare (I need/want to rewire my house and I really wish I could move out while I do it). However, if you can essentially gut the walls, it would be a relatively straight forward job. Without more detailed specifics on the house layout, panel location, etc, it's difficult to say more. The nice thing about the NEC is it basically says what you can and can't do.

Yes and no. If we closed on the house in 30 days, we would basically have another 30 days to get this done before we have to move in or we will be homeless. How long does a process like this normally take? I'm going to call a few people today to get a ballpark estimate as to what is going on here.

a small travel trailer in the back yard ….