me again with electrical question

[mmccool719]

House built in 1910. Electric is all old though doubtful its original. It's knob and tube I believe. How much of a priority should I give to rewire the house? Is it urgent or can it wait a year or so? It's a part time place with 4 of us, and very little electrical usage...no TVs or AC and will be closed up for the winter months. 100 amp service I think.

[Mick_VT]

That largely depends on the condition of it, has it been messed with, has it had rodents near it, etc.

[vvzz]

Many variables. If the wiring is in good shape, all original(no later splices) and not covered with insulation (big no no) then it should be ok for sine time.
If not, then it migt be a fire hazard

[phil]

have a look around and you can see if you can see any black or black cloth tape lumps that would suggest connections made outside the boxes. this would be an indication of someone messing with things I found sevral that were twisted together, very blackened from sparking and covered in old cloth tape. some were visible in the basement but others were inside even plaster walls. the original wiring was done right it was contractors that made it so dangerous.

I found really scary connections over the porch light. check there and see if that wiring is all freyed because it sees outside temperature shifts, the cloth may not last well.

you can put your circuits on arc fault or spark fault breakers. look into the difference and you might get an electrician, this acn be done at the panel.

old breakers can stick. if they are screw in fuses they are safer but never use pennies behind the fuses, check for that.
if a breaker sticks when you do get a short it can make the wires in the walls red hot so I would replace the panel even if you don't rewire but you can be the judge of where and how fast you spend money. often by just looking at the panel you may see different types of wiring indicating updates, or you may see a messy panel indicating the electrician didnt' know what he was doing or just didnt' care. If it looks neat and original that's a good sign but if circuits were updated that isn't necessarily bad. If it's a rats nest of messy connections then that workmanshp may be reflected elsewhere that you can't see.

if you are electrically savvy or have an electrician you could lock out the service and do some things like temporarily tie runs together at the outlets or separate them and do some continuity tests and see if there is any high resistance connections. this isn't a foolproof check but you could find runs where there are problems causing high resistance like the twisted wires I mention. if you have high resistance you have a voltage drop and heat generated and that can go from bad to worse until you get a fire.

if you have any grounded outlets see whats going on sometimes people that don't know what they are doing may install grounded ones in wiring systems that aren't grounded at all like typical knob and tube systems. so dont' let the outlets fool you.
old plugs and switches do waer out. If you find yourself wiggling plugs to make them work get rid of them. I think you can still get ungrounded outlets although not as common.

if you upgrade you may need a larger panel to update the service to a higher amperage , this may mean running a new service line and a new meter and that may mean heavier wires up to the point where the power company hooks up. that and the dryer cable and range cable are the heaviest and most expensive wires. the rest like all the boxes, switches and romex wire are cheap so use new stuff. If you want repro push buttons and things save that till last. inspectors won't wan to see old parts used. wan't heated floors? want electric baseboatrds? electric AC? a suite? want to add a garage and pull power from the panel in the house to a subpanel in your shop? size the panel to what you need for future use

when you rewire , plan it , if you plan to open walls that helps but you can also fish in wires and install new boxes without breaking plaster if you want. pulling in all the wire is half the work and you will want double the number of boxes.

check codes they may call for spark fault breakers for bedroom plugs so put those on the same run to avoid paying extra for the 100 dollar breakers. Outdoor ones and the bathroom have to be ground fault so you could choose to put those on one run or use a razor outlet in the bath. if you blow a breaker you don't wan tot be in the dark so put your lights on a circuit from a different room. some planning before you do anything helps a lot.

there are lots of boxes on the market. the ones I usually use are metal ones with screw holes so you can cut the hole and screw them to the studs without breaking the wall open, some others need to be nailed in before the drywall or plaster is done, avoid those if you aren't opening walls.

boxes ned to be flush, if they ware inset a mm or so ok but if they stick out at all that
s not good because the switch plate won't sit against the wall.

pay attention to the number of wires per box and the number of wire nuts and the number of square inches in the boxes there is a formula and you don't want too many wires in a box for the size of the box.

each outlet in the kitchen needs it's own breaker if the receptacle has two outlets that's two bereakers, if itt's a 4x4 box with 4 outlets that;s 4 breakers right there, so you need a lot more to meet code, the fridge needs to be on it's own but you can couple in a outlet for a plug in clock in the kitchen.. you need outlets every few feet there are codes for that. half my panel is my kitchen plugs and none are shared, this requires a bigger panel. like with shoes, bigger isn't better you want something suitable. you wan the right size for your installation. If you have a big property that service line may or may not be your cost. You dont' want a panel larger than the supply can handle.

your codes may vary. You probably need an electrician. I was able to do it under a homeowners permit and lucky my brother is an electrician so he came by and helped me and advised what to do to make it all pass. If you have a good relationship with the electrician he may allow you to pull wire but some won't as the code says they have to do it.
never walk on the wire or pull hard. if you damage a wire the connection needs to be made in a box so you can mess things up by damaging a cable when it is fished in a long distance. treat that wire with care and the inspector won't want to see footprints and muck on it.

I found the inspector practical. I had almost everything running on extension cords as I had rewired the whole house and he wasn't bad, he let me do that. with the new system youll want ot use some of the old locations so they have to be cut off safely and then rewired but you have to plan it so you can keep using the house if you are living in it and want to do it over time. Other inspectors may not have been so accommodating. when it was all done and every cover plate on then he allowed me to switch the service over from my old breakers to the new and I didn't mix any old runs in. I replaced everything.

what meets code in one area may be different from another so you have to check codes for your area. here the way it works you have to buy the code book and it's pricey and I couldn't access the official local info on line for free which stinks. there are some do it yourself books that are lighter reading I'd start with one of those.

you can get a handy plug checker for about 15 bucks., they just plug into the outlet and show with some LED's if you have wires crossed up or a bad ground, the only work for grounded outlets but you can get one for 15 bucks and they are worth it as all you need to do is plug them in to see if something is wired wrong.

the electrical needs to be bonded to the heating system and plumbing system, don't forget that unless you have all plastic plumbing. its so the wires can short and blow a breaker if they rub on pipes etc.
the inspector will jump up and put his full weight on the panel so make sure it isn't mounted in some mickey mouse way.

if you plan to hook up your own outlets and things at least hire an electrician and have him show you the right wqy to loop your wire, use pig tails. the layout is important. I install them all with the ground pin down and when you loop them and press them to the back of the box you want them on the same side as where they need to go. an electrician will do this without thinking bu there is technique to do it correctly and neatly so the box isn't a mess or crammed.

originally my house had plugs in the baseboards but I wanted to add more and didn't' want ot cut the baseboards all up. decide a height and use that throughout the house so you don't' have plugs and switches at all different heights. it looks nicer if all your switches are the same distance from the floor too. I moved all my plugs and fixed the holes in the baseboards and instead I put them all 11 inches from the floor so they are now all above the baseboards. this isn't to meet code it's just to have consistency. Old houses didn't' have as many outlets as a modern day house wants. I didn't want my baseboards to become like Swiss cheese. even if you hired out you may be able to say where you want the outlets ( always beside a stud)
if you drill holes in studs they should be in the center, two inches in from your drywall , you don't wan to hit the wiring with drywall screws.

I'd do the layout and think about the sizes first, at least when you get an electrician you can make some decisions and see if it makes sense to him. how many outlets you want. if you wan tot pull cable and phone and cat 5 how much? i ran lots and that was as much work and expensive as the house wiring but I just paid for the parts. it isn't part of the electrical but while you are pulling wiring.. want an alarm system? new doorbell wires? I pulled lots of cat 5 but mostly I don't need it now that wifi works better. i ran it all to a central panel and so I can do a lot of things like run my TV or cable to the panel and back to any room or put my routers and things where I want them. I ran lots of cable vision wire because I like antique radios and also wanted to share an antenna with various locations through the house. you can't run the antenna to 6 radios at once or it splits the signal too much but I can send the antenna signal to any location via hard wiring to and from the smart panel. You can get carried away if you want to I disconnected my phone after running hard wires to every room because now I just use my cell Oh well its there and that's ok.

100A isn't tiny so maybe that's ok. I picked a 200 amp one in case I wanted the extras later but I don't draw that much ever. If I want a suite or electric heat I can have that. most other houses have a wire hanging from the side of the house , my brother advised me to run the mast up through the roof and I opened one wall stud bay to attach it with the required U bolts , this is also the location I used to run all my wires to the attic. thats how they want it done , or underground but it may pass if you just dangle it from the side of your house. I had to run triple ought (000) cable, thats thick. the wires pole to pole are the same size. with a 100 amp panel you may not need to move the service unless you make it larger. the supply lines have to be able to carry the breaker rating for your panel and same with your wiring. You can't go installing big breakers and then have thin wires in the walls. the guage needs to be correct but mostly you'll be working with the standard romex most likely.. You can use surface wiring in conduit but its ugly. I have one 20 Amp circuit for my ac or I could use it for a heater and that one required a special red colored cable. the dryer and the stove also require larger cables of course. range cable for the stove.
Phil

[Texas_Ranger]

have a look around and you can see if you can see any black or black cloth tape lumps that would suggest connections made outside the boxes

Uhh... hate do disappoint you but K&T almost never had joints inside boxes! They just ran wires the shortest possible way (sometimes even neutral and hot in different stud/joist bays for maximum short-circuit protection) and spliced off using soldered joints that were then wrapped in two layers of tape whereever convenient. I'd worry a lot more about K&T-to-Romex splices or even K&T-to-lamp cord.

One of the most important spots to check is above light fixtures - the heat from the bulbs can cook the wire insulation pretty badly even with PVC and rubber fares worse.

[phil]

your mileage may vary. mine was done right from the start in 1924 and orriginally all connections were in boxes unless it was messed with but yea if it's soldered at least it isn't going to be like a big resistor that generates heat like it would be if they are all blackened and not soldered. earlier wiring jobs may or may not have followed code or maybe there were no codes. mine seems to have been professionally done and I can tell it was wired before the plaster was done. this might not be the case for everyone. I haven't seen it but some houses were wired with a loop of wire to save wire and that's even worse.

by the way completely unrelated.. I spoke to someone who plumbed their house in a loop and i thought that was kind of a neat idea. if someone is showering it can draw from the loop and because it's a loop it can sort of draw from either direction. its' a way to provide more water without going to larger diameter pipe or making many runs from a manifold to avoid the kitchen sink from affecting the flow at the shower etc.. in terms of cost it made sense to me, less pipe no manifold but It would work well I think. ok but this isn't about plumbing..I just got off track

I'd just advise that if you find these lumps, shut the power off , unwrap them and make sure they are at least good connections. any connection outside of a box is a no no today, You can add junction boxes but you aren't allowed to cover them up. today all boxes are grounded, but my K and T had no grounds only hot and neutral. maybe the actual boxes would still pass if you attach a ground. I don't know.
I just went all new and was never sorry for that. you could also find nasties like aluminum wire that was added at some point. or that old green colored grounded wire that was used in the 50's ? may still pass code. I think K and T could still be done to modern code today with modern arc fault breakers on every run. if you really wanted to you could find out more about what does meet code but since it's hidden I'd just go all new. Who would want ungrounded outlets? so many things want the third prong it would be a PITA in my opinion but if it's a real museum it might be different.

your house insurance company may ask if it's still got K and T and some may not carry you if the answer is yes

good point about the heat damaging wire. maybe you see other houses that had K and T done with the wire joined in places. I don't know how many were originally done like that but I'd just say be cautious. After seeing a few blackened connections that were not soldered in my house and a few other places I can see why it's a fire hazard and worth checking just to see what's really going on even if you don't meet code. Anything is better than a fire ! To actually meet code I don't know,, I guess you'd actually need to run a ground to the box and then youd need two boxes as you'd run out of length to make the joint then and that may be a slippery slope so far as code goes. as soon as you touch stuff technically that has to be done by an electrician and it needs to meet code but should one then not check something like a suspicious lump in the K and T. ? hmm.. I think sometimes practicality needs consideration and shouldn't be advising to break code but if it were my house and I was running K and T I'd want to know if they are soldered at least. even cleaning up the connection and soldering or crimping it and re wrapping would in my opinion be safer than a blackened connection. but then an electrician could argue the homeowner has no place in doing any of it and may not be able to afford an electrician or to stop using his wiring. it's a bit of a catch if you look at the law vs safety and consider the economic situation that one might face. that would be an interesting conversation for an inspector. I think in reality most electricians do spot things like this that are noticeable and don't meet code but their first reaction is the danger and then the code but opinions could vary.

If the electrician is working on something he has a responsibility to see it is safe but if he spots something across the room he might recognize what a can of worms he sees and then might inform the homeowner that to make it meet code he needs a new wire run from the panel. maybe he'd unwrap it and check it and re-tape it as that is at least safer than it was, but in doing so maybe he opens himself to liability because then he's working on something and not making it meet code before he powers on. Its probably a situation where opinions may vary on how to proceed.

[phil]

I thought about this more and realized I didn't' see any connections in the boxes, and there were more boxes than fuses. what they had done is not so much joined wires because they ran out of wire but they had stripped back insulation and made a T in the wiring. Today we would do that in the boxes but since those old boxes are not grounded so then maybe it was less likely that the boxes would become electrified.
I don't think they soldered the connections in my house and that wasn't a safe situation. I had always thought these connectons were done after the wiring , to add more outlets and maybe some were, but for the record. I dont' think they made any connections in the boxes. I stand corrected.

[Gothichome]

The knob and tube in Gothichome was run pretty well as discribed by Texas Ranger, two runs, one for the main floor and a second run for the second floor. Each leg bout 18 inches apart through the joists and on either side of the joists when running parallel to the joists. Each connection soldered and taped with cloth tape. Our was actually in realy good condition, only found one comnnection with burnt ratty tape. Mccool, as long as it is sound, it shouldn't be a problem. We put our wiring replacement about four or five on the priority list. Remember it's been safe for a hundred years or more.

[Texas_Ranger]

Twisted and tapes splices are almost as good as soldered ones IF done properly. Where the wires touch each other they form a kind of cold weld that conducts electricity very well and is stable unless moved/exposed to vibration. In electronics the technique is called "wire wrap". The contact surfaces won't tarnish either because there's no oxygen between the wires. If the wires are just loosely wrapped around each other they can blacken to the point of no longer conducting electricity though or they can move apart and start to arc. That's a real fire risk.

I wouldn't plug in stuff like heaters, 120 V AC units etc. (anything exceeding say 500 W) into outlets fed by knob & tube but then you should be fine. Just have an electrician run a few new outlets and then rewire everything else on a room-by-room basis. You might have trouble finding insurance with K&T wiring though (quite a difference between Europe and the US, around here the insurance companies don't even look at the wiring).

[GibsonGM]

Good reply, Texas. I'd add that one great thing to do with a house with old wiring is to run out and replace your normal 60W bulbs with LED equivalents. You will reduce your electrical bill, but more importantly, the 'stress' you place on your wiring will be several times less!

We're talking about running maybe 6 bulbs on the current that one used to require.