1950's ranch SFH, rewire and plaster walls

16 Replies

Looking to rehab a 1950's rancher, it needs to be rewired due to the old existing knob and tube wiring. It also has original plaster walls in decent condition. I was originally thinking a full gut job in order to make it easier to rewire, but considering the walls are in good shape would it be easier to save them and have the electrician just fish wires through wall (which adds to the electrician labor)? Both the crawl space and attic are wide open. 3 bedroom, 1 bath, approx. 1000 sq ft total. Any opinions on which method would be the most cost effective?

@Ryan Kelly There's no doubt that it would be easier and cheaper to leave the existing plaster and I would not remove it solely for the sake of making the electrical work easier.  

But there may be other good reasons to remove it, e.g. how are you planning to insulate, how are the insides of the walls (dust, droppings, etc)?  

Removing the plaster is a big commitment because its thickness affects everything, trim, windows, doors, etc.  All in all, I generally like to remove it and start with a clean slate.  I think this makes the finished product much better but each situation is different.

@Art Allen Thanks for the insight. Electrical cost is one area I dont have much experience, and I dont have time to get an electrical contractor to give me an estimate prior to making an offer so I'm torn on how to approach this house. I've heard very wide ranges for a total re-wire of a house, anywhere from $3k to $30k depending on size and complexity. This one is a small ranch with good access in attic and crawl space so I assume its fairly simple, but I'd hate to underestimate the rewire cost. I'd really like to save the plaster walls, the windows have been recently replaced with good vinyl ones, so other than the rewire there is no need to replace them with drywall.

Ryan K. In Raleigh, it would cost no more than 8k-10k to re-wire a house like that, especially with good attic and crawl space access.  Also, the plaster does not add much extra work to the job. It's a bit more work to cut the holes for the boxes but they also don't have to staple all the wires inside the walls. As I said earlier, I would not remove the plaster solely to facilitate re-wiring. 

Ryan K. shop around for electrical. Get multiple eyes on it. There are electricians that will realize the job isn't that hard with walls removed. I'd contend local connections matter and there are contractors that understand our "fairly simple" projects should be priced accordingly.

When did they stop using knob and tube? I've never seen a house built in the 50's using this technology. They also may have to cut "raceways" to get the new electrical in so it may not be as easy as simply fishing the new lines through. I've not see electricians not make a mess of things yet when fishing lines. If the electrical is this old how does the plumbing look?

I've personally found it easier to just gut the bathrooms and kitchens to the studs in these cases. Trying to save the rock and patch is a headache and it will look much better with the new rock. Good luck. 

Christopher B., Contractor

My thoughts exactly.  knob and tube was used until the 30s.  I've done several ranches from the 50s and the electrical was fine.  Same with plaster walls.  Are you sure on the year of construction?  Rewiring a house and all new drywall is a big expense and commitment.  you could get lead paint disturbed, asbestos flying around, and code issues.  

The issues in my company's case were too few circuits (4), 60A service with fuse box, no ground, no insulation (walls, floors, or ceiling), no central air (had oil heat though;), ... so 'rehab' had serious limitations unless the electrical was upgraded. But technically the electrical system with knob & tube was fine. Indeed, the drywall was a lot of work.

you can change the box from 60A to 100 or 200A without rewiring the house.  Sorry if I'm stating the obvious.  

Thanks everyone. A quick update, my info source was incorrect, he had it confused with another house that does if fact still have the knob and tube. 

The subject house is from the 1950s but it still has a 60 amp fuse box and ungrounded outlets. So I assume it's still a total rewire of the entire house, unless there is a way to leave the basic room outlets and switches and just upgrade to a 200 amp breaker box. Bath and kitchen would obviously get new wiring with gfci outlets. 

Originally posted by Ryan K.:

Thanks everyone. A quick update, my info source was incorrect, he had it confused with another house that does if fact still have the knob and tube. 

The subject house is from the 1950s but it still has a 60 amp fuse box and ungrounded outlets. So I assume it's still a total rewire of the entire house, unless there is a way to leave the basic room outlets and switches and just upgrade to a 200 amp breaker box. Bath and kitchen would obviously get new wiring with gfci outlets. 

 How did this work out for you Ryan? Did you do a complete rewire or did you just upgrade the box?

Should be able to just upgrade the box for fairly cheap (100-150 if you do it yourself).  May also be prudent to upgrade the service wire but that will probably require a permit.  You could even put 3 prong GFCI outlets if you wanted with the "no equipment ground" sticker but I don't really feel like 2 prong outlets are much more than an annoyance.

Every house I have done were 1950s. Every one had wiring that was fine. One had an upgraded 100 amp service and only needed lights and 3 prong outlets. Work I did myself. 3 of the houses needed service upgrades. 100 and 200 amp. The wiring on the walls do not get replaced unless there are issues. So far kitchens have been redone, as they are gutted, as well as baths, but no other rooms have been taken to studs or rewired. One of the reasons I have liked the 1950-1960s houses I have seen.

@Brian Pulaski

Regarding "...One had an upgraded 100 amp service and only needed lights and 3 prong outlets. Work I did myself." I hope I'm not seeing this as you swapped out each device with an ungrounded outlet with a 3 prong (perceived by tenants or anyone else as grounded) device. If so, you must realize the circuit isn't grounded. You are personally liable if something goes wrong. For sure if an inspector finds out (like you try to sell the place) you will be in violation of the building and national wiring codes. A simple circuit tester will show a ground fault.

OP, research your building code... maybe a GFI or GFCI solution exists. But what Brian posted, taken literally, is a bad practice.

Disclaimers: I am not an electrician. This post is for entertainment and not to be construed as advice in any way. Employ a license electrician for all your electrical work.

@Chris Martin I guess I wasn't specific enough. My homes had metal boxes with BX cable. In these situations, the cable and box acts as the ground (in lieu of a dedicated ground wire seen in Romex and plastic boxes). The old 2 prong outlet comes out. The new 3 prong then goes back in, grounded to the box, which is in turn grounded to the BX cable jacket. This solution has passed inspections by everyone who has seen/inspected it. I assume knowing this added information, what I'm doing is normal and not incorrect practice. If it still looks that way to you, I will need to speak to the few electricians who have done exactly this work for me and didn't say it was against code and dangerous.

@Brian Pulaski 10-4.

Unfortunately I've seen 'new' grounded outlets in 1950's era houses with ungrounded electrical service. I also experienced CU devices in al AL wired house. It was an REO w/o inspections. After closing prior to our contractor's arrival, I remember turning on a light switch wired to a wall outlet (with copper device) and the damn thing caught fire. We promptly hired an electrician who pig-tailed it... and added a circuit for the dishwasher.. all to code.

I'm sure a lot of sketchy work is done when it comes to electrical. Electrical happens to be the one major item I rarely tackle. At best I install some outlets, replace lights and have been known to install boxes and rough in for my electrician. When it comes anywhere near service, a panel or anything larger than simply swapping out items, I leave it to the pros.

I had one outlet on me trip the breaker after replacing it. Turns out there was a small tear in the covering in the box that I couldn't see. When I investigated, the wire broke off in my hand. Luckily there was enough to still connect, if not I would have been removing the run completely and rewiring it. This would have most likely had me calling my electrician.

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