Electrical rewiring of whole house
July 17, 2017 11:02 AM   Subscribe

We have a 1920s house with knob-and-tube wiring and plaster walls. We're looking at getting the whole thing re-wired and brought up to code. What should we think about? If you've done this, what was your experience?

It's two floors of living space, plus unfinished attic and basement. Currently we have a fuse box and 60 amp service, which would be upgraded to 200 amps and a new circuit breaker panel.

We have a proposal from a really good company that we've used before. They predict it'll take 4 guys about 2 weeks, and we can live here through the work. The cost is a little on the high side but in the ballpark of what we expected. (This is their reputation, they're more expensive but do a really good job. Their contract says we don't pay anything until the work is done to our satisfaction.) We've been saving up for this for 8 years and can afford it. It's just a giant undertaking and a lot of money, so I'm nervous.

I really want to preserve the plaster. They say they can do it mostly by fishing wires up from the unfinished basement and down from the unfinished attic, so the only holes they anticipate cutting in the plaster will be in the first floor ceiling for the ceiling lights. They don't do plaster repair, but can give us names of companies that do. They're experienced in doing this job in old houses; he said they do 3 or 4 a month.

What am I not thinking of? What should we add while they're in there? What should we expect during the work?
posted by LobsterMitten to Home & Garden (23 answers total) 11 users marked this as a favorite
 
I just did a wiring upgrade in a 1959 house, and it took about two weeks longer than expected. The new breaker panel (I went from 100A to 200A) was much much larger than the old one, so it involved cutting a good-sized hole into the side of the house. Not bad, just surprising.

Depending on your local building code, you may find some areas have to be served by arc-fault breakers, which can be a tad over sensitive. I now have one circuit that's got a microwave and an AC on the same circuit (well within amperage for the line) and I have to be sure to turn off the AC before turning on the microwave or I'll trip the AFCI. Watch out for that type of thing, I guess.

Consider what cooking appliances you might want in future -- do you want a 50A circuit for a possible induction cooktop?
posted by aramaic at 11:11 AM on July 17


Consider adding a whole house surge suppressor on the new panel. Also, a 30 amp circuit for your future electric car.
posted by LoveHam at 11:14 AM on July 17 [6 favorites]


+1 on the whole house suppressor.
posted by Dr. Twist at 11:32 AM on July 17 [1 favorite]


Consider going past 200 amp to 300 amp to accommodate future electric car charging. The marginal cost is relatively small, and the labor is basically the same, but will only be done once.
posted by rockindata at 11:33 AM on July 17 [3 favorites]


MsNMRN and I just bought a new home in the Boston area, and in the process looked at a lot of older homes that still had K&T. The biggest issue for us were the in-between places: Homes where the electrical had been upgraded, but some or all of the old K&T was left behind. Apparently, this is not uncommon.

For insurance purposes, that would have to be removed. Which would cost a lot of money, and be a pain in the ass. But unlike a total electrical upgrade, which would have the same downsides, there's no real benefit to us in the end. It just makes the house insurable. For that reason, we ended up writing off any property with new electrical, but old K&T remnants in the walls.

At some point in the future, you're going to want to sell this property. For the sake of your future self, make sure all the K&T is removed during this process. Otherwise you're diminishing your pool of potential buyers, or lowering your possible future sale price.
posted by NotMyselfRightNow at 11:33 AM on July 17 [4 favorites]


I would try to talk to a few of the customers of this company. The company is saying all of the right things but, frankly, that's what all the companies are going to say. And, although you've used them before, I assume you haven't used them for a project of this scale. In particular, I would try to find a few recent customers who are as close to your situation as possible (i.e. whole-house rewire, want to preserve plaster walls/ceilings) to serve as references. How well did they actually do in preserving plaster? Were their time estimates approximately right? Did anything unexpected happen? Ideally, these would be people known to you but, failing that, you should ask the company for a recent reference.
posted by Betelgeuse at 11:46 AM on July 17 [3 favorites]


If your old house is anything like mine, the only plugs were for a lamp and maybe a radio. Add a bunch of plug outlets in rooms where you have electronics or computers. Every wall needs at least one plug and some rooms need many more. Get plugs in big closets, get plugs in crawl spaces, get plugs on your porches, in the bathroom, in the kitchen. Get more than you think you need. It's the ideal time. Not much disruption to the walls with the fishing wire method.

My installer disregarded my instructions about the number of plugs to install and I've been mad ever since. Make sure they install as many as you need and WHERE you need them.
posted by a humble nudibranch at 12:01 PM on July 17 [4 favorites]


Sister who got this done says this is a good time to check if you need to up the amperage to the house while you're in there which it looks like you're doing. She decided her plaster walls were too fragile and opted to get a lot of outlets ("Get SO many more than you think you need!" she says) put into the baseboard molding instead of the walls themselves.
posted by jessamyn at 12:14 PM on July 17


Put outlets in the hallways. Whoever vacuums will thank you.
posted by TWinbrook8 at 1:01 PM on July 17 [1 favorite]


You may want one or more 220 v circuits, if you later want to spring for a whole-house air conditioner or electric dryer/washer.

Make sure that the kitchen has at least two circuits (to avoid the "turning on the microwave kills the toaster" problem).

This is the perfect time to consider whether you'd like three-way light switches, which permit you to turn a light on when you enter and shut it off as you exit from a different door.

You can not have too many outlets. Double outlets on either side of beds. Maybe add double outlets to the other side of the room so you can rearrange the bedroom! Overhead outlets can be very handy for using irons or power tools.
posted by Jesse the K at 1:15 PM on July 17 [1 favorite]


For the sake of your future self, make sure all the K&T is removed during this process. Otherwise you're diminishing your pool of potential buyers, or lowering your possible future sale price.

Seconded. Our 1925 house has mostly new wiring (except in the attic) with knob and tube remnants left behind. We didn't mind ourselves but if we had been using certain types of loans to buy the house, they would have rejected it immediately.
posted by chainsofreedom at 1:30 PM on July 17


I bought a house just last week, right now electricians are updating my 1917 bungalow by replacing all the knob-and-tube and upgrading the remaining wiring. Right now as in, as of this morning and will be well into tomorrow. Bathrooms has some weird ass wiring back when our homes were built. This is the second home I have owned where there was a light switch in the shower... IN THE SHOWER! Then there was my kitchen that had four separate light switches leading to different lights. Have electricians look at not just outlets, but weird switches, lights, and fans to see what can be removed or consolidated.
posted by munchingzombie at 1:50 PM on July 17


These are all really good suggestions.

I'd emphasize that this will be pretty invasive, and that it's really helpful that your basement and attic are unfinished. You still may end up with holes in weird places. It is very good that these people do this regularly - this is a totally different process than wiring up new construction.
posted by aspersioncast at 1:54 PM on July 17


I had this done at my house. It can get really really messy. Cover furniture with tarps, plastic etc. Considering the age of your house, keep in mind that the base layer of paint is almost certainly lead based. If you have young kids you may want to consider keeping them out of the house for the duration. And line up your plaster guy to start right after the electrical is done. You don't want to live in a house with holes for a few weeks.
posted by trigger at 2:54 PM on July 17


We've had this done to both apartments in a 2 family, and what your contractor told you sounds about right. You are fortunate you have only the two floors; our 2 family has 3 and getting wires to the 2nd floor required a fair amount of demolition.

If as it sounds you're hiring a good sized firm, be aware that whoever you talk to when you hire them will very likely not be around to do the actual work, or not all of it. Do not assume that any special instructions you give them will be conveyed intact to the crew that actually does the work. It is therefore a good idea to be around when they arrive, and review any special concerns you have, e.g. about minimizing damage to the plaster. Actually, the more you can be around during the project, the better, there will always be surprises, and the crew's idea of what is best (get it done as quickly as possible) won't always align with your desires to keep the mayhem under control.

While I agree that you should get some additional outlets installed, I don't understand the point about "putting in a 30A circuit for your future electric car". Assuming your main panel is in the basement, as most are in houses with basements, as long as there is space left in the new main panel for more circuits, adding additional breakers at a later time is no harder than adding them now.
posted by mr vino at 3:28 PM on July 17


We did this, 1947 northern California cottage, one story. We had amazing luck with tying a string to the wire in the socket or switch box, pulling really hard from the attic or crawlspace, and then using the string to pull back in Romex. Every once in a while the old wire would break, but we never broke both of the separate wires, so there were only a few places we had to open up the wall.

Took two of us much of a Christmas break. We planned it so that we could do it a circuit or a room at a time, that helped, because we had a good sense of intermediate completion as we went along.

I didn't learn this 'til after we threw away all of the ceramic we removed from the attic and crawlspace, but there's apparently a large market in used knob and tube parts, so whatever you remove in one piece, put in a box and ship off to one of the places that buys this stuff.

You will probably be asked by your city to upgrade socket density to modern standards (ie: roughly every 12', at least one per wall). More sockets better. Several places we put in extra sockets in the room, or 4 gang outlets by the living room couch so that we didn't have to drop a power strip for plugging in phones and laptops when we're hanging out there.
posted by straw at 3:55 PM on July 17


As for extra outlets you might want to consider adding them to the top of the mantle or any built in shelving you have to power lights, clocks or decorations. If you don't have outdoor outlets or don't have them in all the convenient locations, now would be the time to add them.
posted by mmascolino at 7:18 PM on July 17


You get to walk thru your house and choose where things will be convenient. I would suggest that before your contractor starts to work (been there done that) you get a complete site design drawing with where the outlets are located where the light switches (on/off and 3 way) are located. Where your (within the next 5 years) electric car's charger will be located. How may circuits you will need in your kitchen (ditch the disposal and put in a 4 block for the coffee maker) Whether your stove is gas and the convection oven needs how much current. Or you get an induction cook top. How much does your bathroom need for the blow dry and curling iron. Where is the workbench and it should have at least 2 full circuits. Get it on paper. Walk around and picture it.

Tell your contractor to pull all the K&T pieces including the wire (will be an added expense but worth it comes sales time) which you can sell or donate.

Be involved from a usage standpoint, it's YOUR house. If the contractor balks at your expectations get an explanation that makes sense or just make sure it gets done.

Depending on how many walls you have you can expect the full job to take a crew a work week to run wire, an additional day of effort to pull out the old stuff and since electricians generally work 7.5 hour days with .5 hours for lunch and no breaks you should be able to live there while they do their business.
posted by ptm at 7:18 PM on July 17


A wonderful thing we found in our house when we bought it - ethernet on every floor. If this interests you, you might want a quote on it. Yeah, everyone uses wireless, but I love having appropriate computers/devices having a hardwired connection (also makes it a breeze to add wireless in different parts of the house).

Also, having a case of bottles of water and a selection of soda that your contractors are welcome to is something they'll appreciate, and it'll cost you next to nothing (compared to the rest of the work).
posted by el io at 10:59 PM on July 17


nthing many many outlets.

Ceiling Fans are cheaper than AC - or a good supplement.

In-closet hardwired lighting is nice.

Both are trivial - I'm sure you could do every room & closet you wanted of these in 1-2 days extra while the walls are open.

If you wanted to get fancy and you need AC and there isn't central ac, ductless split is MUCH better than window units for noise and energy efficiency - although this is more work. God I hate our window units (we're in a co-op and can't poke through walls).
posted by lalochezia at 6:03 AM on July 18


Get a much larger panel (as in room for number of circuits) than you initially think that you need. When we upgraded our panel from 100 amp service, half on a breakout with fuses, have on a circuit breaker to one panel we didn't ask for anything special, so there were minimal empty circuits available. Now, after adding a hot tub, we have only one circuit available - if we for instance put in a special charger if we get an electric car, that won't leave us an option for 240 volt charger, unless we forever disconnect the 240v previously used for the stove (we went to gas) leaving stranded non-live cable (which I don't think you're supposed to do).

Yeah, it's not often that you're adding extra circuits to an existing panel, but really are you going to care about 6-8 inches of space and maybe a few hundred more given the budget of this project?

In-ceiling lights in every room. Death to lamps. Dimmers are more sensitive on 3-way circuits.

Any in-ceiling octagon box should actually be a box capable of ceiling fan support so that you have the option.
posted by nobeagle at 7:55 AM on July 18 [1 favorite]


Whole house surged protector - This Old house segment. Damage from a surge cost $10k. Installing a box under $500.

Review if every room has enough outlets - especially by the Tv.
posted by Crystalinne at 8:43 AM on July 18


It's done! Or the electrician part of it is done. The power company still needs to do their part of it. But the invasive indoor part is done. It went well!

Thank you all for your helpful answers!

Lots of notes here in case someone in the future finds it useful.

Things went exactly as the company told us -- it took four guys two weeks; we were able to live in the house during it, no problem; and they kept the holes in the plaster to a minimum. Most rooms just have a couple of holes, mostly small enough that we could patch them ourselves - the size of an outlet or smaller. Only in a couple places are there larger holes, the biggest being around 6" square. They removed all the old knob-and-tube from the basement, so hopefully future buyers won't look at it and wonder "is there old wiring still active somewhere".

We went with the company with the great reputation for customer service and they lived up to it. They were careful about the plaster and the other delicate house elements. They were thoughtful about how to gain access to places non-destructively. They were super-super considerate of our schedule and needs, being sure to keep the essential stuff (internet, fridge) powered on using extension cords, and returning us to almost full power every night. They were respectful of our space, which is really nice when you're working from home (for example: even the young guys have clearly been told to be quiet -- they don't let tools drop, they place them down; they don't shout up to the guy on the next floor, they either walk up there or they use phone walkie-talkies - it made a surprising amount of difference!), and cleaned up as they went (and even so, plaster dust escapes).

I wish I had been clearer up front that I wanted them to save the old fixtures (the push-button switches and switchplates, etc) and stuff; as it is, I have some of it but a few things got lost in the shuffle.

- - - - - - - - - - - -

Changes were pretty minimal since we already had one outlet/wall in most places, so they were just replacing those. But we:
- moved some lightswitches to more logical locations
- removed a couple of old fixtures that were a nuisance
- split the formerly single-control bathroom light and fan onto two separate switches, so you can put them on independently (yay)

Added:
- much bigger panel
- proper grounding and bonding
- wired smoke alarms and carbon monoxide detectors
- whole-house surge suppressor
- proper outdoor outlets in the front and back of the house
- an extra outlet by the tv, for the kitchen counter, in the hall, by the laundry area
- an outlet with USB built in for a phone charging station
- multiple circuits for the kitchen
- dimmer switches for the bedroom lights
- light-fixture boxes that are able to hold a ceiling fan, in the bedrooms, and space in the lightswitches for fan controls
- new LED ceiling lights for a few rooms including the kitchen (so much brighter, awesome)
- better lighting in the basement that all comes on at once (yay)
- new push-button lightswitches in two locations, as a reminder of the original wiring. They're more cheapy-feeling than the solid THUNK of the original article, but are okay. I got them online from Classic Accents. (The electrician said, belatedly, that the old ones can be taken apart and have proper modern guts put in them? Which, I wish we had realized that earlier, I would've maybe tried to do that.) But we went with regular toggle switches in most places.

Things we didn't add but might have -
- separate heavy-duty outlet for things in the basement like the dehumidifier
- separate heavy-duty outlet for a large window AC unit (small window ACs are ok on the normal circuit for a room, they said)

- - - - - - - - - - - -

The process was:
Day 1: Run wire from the basement to the attic - a lot of wire.
To do this, they find a stacked first-floor wall and second-floor wall that allow a continuous vertical run, and they drill holes in any blocking elements they find, until they're able to fish the wires up, using fish tape -- which is this long skinny semirigid metal pole that the downstairs guy wangles and crashes around inside the walls, and the upstairs guy tries to catch and pull up. Each wall has its own weird internal quirks, so they kept running into different materials and having to find a way through or around. This first day involved cutting the biggest holes, in a few places along that vertical run from basement to attic.

Day 2-5: Wiring the second floor
Once they have the huge bundles of wire threaded up to the attic, they work in teams -- one guy in the attic and one guy on the second floor -- to pull/feed wires down inside the other walls to innervate the outlets and ceiling lights and smoke alarms. There was some small hole-cutting involved here.

Day 5-8: Wiring the first floor
Wiring the first floor mostly involves pulling wires up to the outlets (etc) from the basement. The tricky bit is feeding it to the first floor ceiling lights, and that involved cutting small holes at the edge of the ceiling.

Day 8-10: Basement
Installing the new panel and attaching all the new circuits to it. Doing the big appliances like the stove and dryer that get their own special large circuits. Putting in the two outdoor outlets, which are fed from the basement. Taking out all the old knob and tube and old junction boxes and whatnot.

I enjoyed watching the whole thing. For example, I hadn't thought about how much is involved in the lightswitch at the stairs: the switch at the bottom of the stairs controls the light at the top of the stairs (there's also a switch at the top of the stairs, they're 3-way switches). To make that connection, the wire travels from the 1st floor switch, down into the basement, across the basement ceiling to the other side of the house, up inside a wall to the attic, back across the attic floor, then down inside the wall to the light and the upstairs switch. It's a long piece of wire, and the electrician has to know in advance more-or-less what length of wire he needs before he sends that big bundle of wires up to the attic, and the apprentice who's stuck on (dark, dusty, hot) attic duty has to keep track of which wire it is among the profusion.
posted by LobsterMitten at 7:13 PM on September 24 [4 favorites]


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