Just about every "alphabet" group you can think of recently took part in a survey of older homes, and their electrical systems.

30 homes, slated for demolition, were examined from service drop to outlet. Components were sent to a lab for further examination and testing.

With the NFPA asserting over 24,000 household fires - and a disproportionate share of these being in homes older than 40 years - are caused by the electrical system, what causes do you think the study found?

(I'm cheating ... I have a preliminary draft of the report ... I just want to see what "conventional wisdom" thinks )

I suspect homeowner modifications will rank high on this list. As will deteriorating insulation. And probably a certain amount of damage from rodents, birds, and the like.

I expect there will also be assorted problems at receptacles.

Thirty homes is a small sample considering the number of homes that don't burn down. I would guess that very few had electrical problems.

I think most problems are on the load side of the outlets.

I have to agree with Greg that what is plugged-in would be a primary cause. A lot used to be attributed to 'overfusing', in the days (and areas) that edison base fuses were prevelant, of which I saw my share.

I remember the guy at a local hardware store commenting something to the effect of....'we used to sell a lot of 15 & 20 amp fuses; but since a lot of people started buying the 30's, sales have slowed way down'.

Fire cause determined to be caused by 'electrical' seems to be vague; it should be broken out into utilization equipment and premises wiring.

I'd say improper use of extension cords would be #1 and fuse tampering would be #2. I get so mad when they report a fire on TV news and cite the cause as being electrical. Later they report that three portable heaters were plugged into a 100' 16/3 extension cord. That isn't an electrical fire.....That is a stupidity fire.

Something tells me that aluminum wiring is going to get thrown under the bus on this report too.

Actually ... aluminum missed the bus - this time! The houses all pre-dated the aluminum wiring craze.

I'm right there with you on this!!!
But I say "Fire alarm" and my insurance rates (liability) go right thru the roof !!!! I prevent this crap!!! (Or at least detect it)
But I digress.. I will go with poor/loose connections at the devices. Wich coincides with the overloading of appliances. (whoa.. Both ends to the middle. Smooth.. No?):)

As stated above, I'm sure deterioration from misuse on the load side is gonna be right up there.

Also, I would guess that, if the homes were old enough, they probably found quite a few exposed wire joints. I've found that the old solder-and-wrap method of wire joining, although good from an electrical conduction standpoint, suffer from deterioration of the wrapping materials and don't handle maintenance and handling too well. Also, a few times being pulled in and out of the junction box for add-ons and repairs tends to break up the old cloth insulation pretty badly too.

So, I would guess that they would classify this as "post-build maintenance damage", or something like that.

Induced voltage is also prevalent in these old installations.

Improperly bonded and altogether loss of the grounding system also comes to mind.

BTW, what a great idea for a study... I'm sure there was quite a bit to learn from this. I would have loved to have been on that archeological dig.

I'll go with Ed on the stupidity, especially plugging a few too many space heaters/blow dryers/air conditioners into old 50s circuits, which already serve most of the house.

My second would be homeowner/handyman tampering, based solely on the pictures I've seen here.

Ian A.

I'd say deteriorated grounds, damaged insulation, and evidence of overloaded receptacles tops the list.

Having seen a number of "electrical" fires, i.e. the source of ignition was electricity, the causes I've seen mostly go from miss-use to DIY repairs.
Portable heaters on extension cords or too close to cumbustables.
Light bulbs against combustables.
NM cable tapped onto knob & tube, with some tape wrapped around the joint.
Panels with different brands of breakers jammed in, they almost fit.
Biggest cause of failures: Users and hack repairs.
I still remember the guy that swore he did not put a penny behind a fuse, that over loaded and caused a fire. He said, My momma told me to never use a penny behind a fuse. That's why I used a nickle.
It is easy to put 20 and 30 amp breakers in where those 15's were. Those will be the fires of the future.

I'm trying to figure out why these taps would fail. They should be no more dangerous than the original K&T, which I am given to understand is quite safe. The modern tape and solder should be even better than what they had originally.

I think Alan means just poorly made splices, like just loosely wrapping the new wire around the old and taping it up. I doubt any average person would go as far as to solder the joints etc.

OK John, time to fess up, what is most likely to burn my house down?

Ian A.

From the original post.



So the things that were on the load side of the outlet, ie: extension cords and heaters etc. were not part of the examination!

... Except the extension cords that were still in place.

I cheated too

The home owners must have packed up all their extension cords and heaters when they moved out. Anyway, this study might find that the average house's house wiring (as part of the house itself) may have few serious defects. Serious enough to fail in a way to cause a house fire. Some that almost caught fire (charred insulation, but didn't quite burst into flames, or the fact that the metal junction box kept the embers off flammable materials and saved the day), other problems that were never stressed enough to get even started on the way to a fire (code violations that would have failed seriously if they were ever asked to fail in a safe way (penny behind the fuse, but no overload or short ever happened on that circuit)).

I know someone who had an "electrical" house fire. He was cleaning his basement, and moved a space heater to a temp storage spot next to some other stuff but didn't notice that it was still plugged in. And he usually catches things like this, but somehow not this time. Later its thermostat decides it's cold, and turns the heater on, and the stuff next to it catches fire. User errors like this may explain most electrical fires.

This study would still be worth while, if nothing else than to identify the areas that really need attention (like the heater on extension cord).

I must confess to knowing the results of this examination .....Reno told me on the ECN chat.

The study confirmed a lot of electricians' beliefs - and directly challenged the assumptions behind much code growth.

First, for the "non-problems."
"Old" equipment generally performed well, when subjected to the same UL testing as was done at the time of manufacture. That is, wire insulation (even brittle rubber) and circuit breakers (even FPE and Zinsco) worked, unless they were damaged in some way. Likewise, old switches and receptacles either did just fine, or had some obvious problem with them.

The houses either had very few / no code issues .... or had plenty. As in 'more than 25.' here we are speaking of basic violations (things like over lamping and over fusing), rather than, say, not having the more recently required telephone jack.
The code problems were -no surprise to sparkies here - generally associated with poor attempts to change / modify / "improve" the original electrical system.

Probably the biggest hazard found lurking within the homes was suggested by signs wires had overheated. This was indicated by either the older rubber insulation decaying, or by scorched insulation. The most common site of this was near lighting fixtures, suggesting over-lamping for extended periods. There was also the matter of over-fusing.

Poor splicing / flying splices / and double lugging were all common features of additions to the original electrical work. Sometimes the report understates things: for example, "extension cords left in place" was a very nice way of describing a cord that came out of a receptacle, a cord that was then stapled to the baseboard, and then went in a hole in the wall - where it fed a newly installed receptacle. Such cords always had several coats of paint. (Though one more recent such was found, only it used the newer yellow romex :D)

Receptacles found generally fit into two categories: either they were the original two-prong type, or someone had replaced them with three-prong types. In several instances, the three-prong receptacles were wired in a manner that would fool a plug-in tester.

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

Just for grins, let's look a my personal home. I think this will show what we have to deal with.
My place was built in 1940. No skimping here - it was wired with romex that just might have come from the very first production run. Very 'cutting edge' at the time; K&T was commonly used in this neighborhood until Kennedy was President.

The kitchen had a single receptacle - you could only plug in one item. In the only electrical change made over the years, a duplex receptacle was added for a refrigerator. Naturally, this receptacle was installed in a non-compliant manner.

Wires near the lighting fixtures (both of them!) is in good shape. The reason for this is suggested by the fact that I still have the glass covers to these fixtures; over-lamping was prevented by the lack of room in the globes.

The main room, which measures about 12 ft square, and has 28 ft. of continuous wall, has a single duplex receptacle, part of which is switched. There's another 6 ft. wall section, and there was a 4 ft. section - both without any receptacles. It's safe to assume that this room has seem many extension cords / power strips / cube taps / adapters over the years.

It's very likely that the room was once larger, with the wall that creates a bedroom being added later. This would account for the presence of three receptacles in the bedroom - none on either side of the dividing wall.

The only receptacle in the bath is the one in the base of the light over the sink. Two prong, no GFI.

The original service - in use until a few years ago - was a 60 amp fuse box. Two of the four fuse spaces were used for household wiring. A third was for the space heater in the bath. The range fuses were not used (gas range). The water heater was fed from a second meter.

One outside light; no outside receptacles.

I think we can see how my place's electrical is inadequate for even a fairly modest modern life. I know, it's hard to imagine a kitchen without both a fridge and a toaster - but that was the state of thing in 1940. Likewise, out living rooms have far more to plug in than just a radio and a lamp.

So... when's your power upgrade going to be finished, reno? Not like you to sit back and see what would otherwise be horrible code violations and say "ayup, grandfathered in!"

Thanks for the info John, guess it's time to rip down the three recessed lights (which I found out are nothing more than aluminum dunce caps with a light socket.)

I guess the standards changed by the early 1950s, since these Levittown houses have at least two + one switched receptacles in each room, makes for a little less power strips and extension cords.

One run (+/- 60 houses) of Fairless Hills houses are worse, one receptacle in each room. And if there wasn't a light on the ceiling, half of that was switched. Gotta love pre-fabs though, with their 24" on center 2X3 walls. I still wonder how the TWP lets people put second stories on them.

Ian A.

Steve .... I work hard all day ... when I get home, the LAST thing on my mind is doing electric work, for free, for my landlord!
This contrasts to my neighbor. He 'flies a desk' in the 'chairborne division' of a local manufacturer. Now, he simply cannot wait to get home and tend his garden, work on his car, etc. Must be nice

As for my place ....
I've replaced the service. The bath heater is on a GFI breaker. All receptacles (except for the one in the base of the bath light) are GFI protected. I'm starting on the -major- kitchen remodel, which will address the refrigerator receptacle issue. Outside receps have been added, and I've added to the outdoor lighting. I have relocated the kitchen light switch and thermostat.

All told, I was very happy to get the place with only one code violation - the hacked in refrigerator receptacle. The rest of the electric was in a marvelously untouched condition - quite a feat in a place nearly 70 years old. All the other 'deficiencies' (like the lack of receptacles) were likely in compliance with the codes at the time.

John:

Your place reminds me of my grandmother's place in North Carolina that my grandfather had built in 1952. She had electrical work done only one time in the 50 years that she lived there, which consisted of a sub panel and dedicated circuits run to all bedrooms for window A/C units in the 1960's. It was a crappy job: A Wadsworth panel with runs going into the crawlspace, then up the outside walls with UF.

Despite the age of her house, I was surprised that she had the original 100 amp fuse service. She had oil heat, but everything else was electric and even as a kid, I was fascinated by the fact that nearly everything was in pristine condition. This place must have been state-of-the art when it was built because they had properly-placed receptacles, outdoor lights and receptacles and lots of 3-ways. All switches and receptacles remained original except for one switch that I replaced in the pantry.

When we moved her out, we cleaned out the attic that had been a virtual junkyard of old toys, books and furniture. I was amazed once the place was emptied out how similar to today's standards the wiring was. It actually looked a lot neater than most of what you see today. It was all Romex (with ground!).

The people who bought the house did a major renovation, to include a service upgrade to 300 amps and central A/C. The new owners were family friends and they insisted that the old fuse panel behind the door in the kitchen remained. It was completely dead, but they wanted to keep it there for nostalgic purposes. When we went there for a visit, I was delighted to see that this original "hub" of the house was left untouched. I know it sounds silly, but there's no doubt that there was a lot more quality and pride in workmanship 50+ years ago.

GRRRR!

While this study has not been yet released in it's entirety, I am far from the only person to get a draft copy.

The study pointed quite clearly to improper modifications to the home as the source of nearly all of the code violations. Please note that the study has NOT identified any hazards not already covered by basic code issues.

Yet ... in the latest IAEI internet weekly newsletter, the lead "article" starts off by stating the older the home, the greater the risk of electrical hazards - so far, so good - then starts plugging tamper-resistant receptacles as the cure !!! Not AFCI's, not corrosion-resistant products ... but TR!

This is a classic example of false logic. No wonder some posters have accused the NEC of being little more than a sales campaign for manufacturers!

As you might guess, I'm more than a little upset.

These findings prove the old addage that if it ain't broke, fix it 'til it is broke! I've seen it with cars, motorcycles, and homes. People think they know more than a professional and always have ideas on how they can "improve" something they actually know nothing about. The end result is usually a nightmare, and with electrical, a very real danger.

Oh well, if the "toolbelt diva" can do it...

I am looking for a Wadsworth fuse block for 2 non 100 amp fuses

Good luck! That house is WAY overdue for a service change, as well as a long, hard look at the changes that have been made to it since it was first built.

The reason for no refrigerator receptacle on the original build is related to the gas stove. It would have had a gas powered refrigerator. Very popular for years, until "they" noticed it had no vent to remove the CO from the kitchen. Same for the very popular gas heaters in bathrooms.

Frank DuVal

When most of us old guys were growing up, nobody seemed to care about unvented gas stoves and fridges in homes. I guess they were "loose" enough that we were getting a lot of fresh air makeup.
We did have a friend who had a house that gave everyone a headache if you were in the basement (with the furnace on)
I know now that we were being poisoned. I avoided it whenever possible, even then.

I remember a gas fired water heater. A coil inside a cast housing with a gas burner at the bottom. No vent, and you opened the front panel/door and lit it with a stick match.

I guess that was the 'first' on demand water heater! It was in my grandmothers house way back when.

The kitchen stove was coal burning; or wood if you had no coal.

It has likely already been mentioned but I didn't see it while reading through...

How many of the code violations were a result of hiring a "handyman" vs an actual qualified electrical contractor? He'll paint, frame, plumb and wire your house for a fraction of the cost.

Up until the 1980s there were plenty of small un-vented on-demand gas water heaters in several European countries (and by that I mean they could be legally bought and fitted new), even considerably longer in some countries I think. Those units were small (5 l per minute flow rate, roughly 1 1/4 GPM) and only to serve sinks. Using them to fill a bath was illegal because of the extended operating time. My dad once lived in a place with such an illegally installed one and says the fumes were definitely nasty! I think my mom wanted one fitted to the kitchen sink around 1987 and it would have been possible, except our gas pipes were too leaky for the required pressure test, even though they were still tight enough not to cause any trouble in normal use.

Cookers (kitchen stoves) were never vented in continental Europe, with very very few exceptions (I've seen ONE in my entire life). The authorities don't seem to be concerned with them either, unlike with flue-vented boilers and water heaters. If you've got one of them any extractor fans in the house must be automatically switched off as soon as the boiler kicks in!