Old House Electrical Concerns

By: Bill Kibbel , Contributing Writer
In: Old House Inspection, Old Houses, Old House Construction, Home Improvement Tips

What does “updated” mean when it comes to the wiring in an old home?

In response to an article about knob and tube wiring, I’ve received many e-mails with questions about old house electrical issues. The age of the wiring in an old home isn’t the only part of an electrical system that can fail or become unsafe. It’s a “system” that has numerous components that have different functions. Many of the questions I receive seem to indicate there are some misconceptions about what the term “updated” implies when an old house has had some recent electrical work.

I see many real estate listings describing that the “electrical is completely updated.” What I typically find is the old fuse box has just been replaced with a circuit breaker panel. I also occasionally see property disclosure statements claim “old knob and tube wiring replaced.” Close inspection often reveals that most of the readily accessible old wiring in the basement was replaced, but is then spliced to the old wiring, just before going up into the walls. It’s quite common to find the knob and tube wiring still active throughout the rest of the house, with numerous safety concerns still present.

Knob and Tube Wiring

Knob and Tube Wiring

These are some of the most common issues that I find regarding aging electrical systems:

Service Entry Cable
The line from the overhead wires to the meter and from the meter to the main panel has a protective sleeve that is constantly exposed to the “elements.” Older systems have a cloth covering that is often frayed or completely worn through. Some early vinyl sleeves crack and crumble when regularly exposed to direct sunlight. These conditions can allow water to entire the service cable, which then drains into electrical equipment enclosures. Enough deterioration of the cable covering can expose the individual conductors inside to become damaged.

Distribution Equipment
Fuse boxes are an indication of an old electrical system. I don’t consider fuses to be inferior to circuit breakers. They are quite reliable at doing their job–overcurrent protection. The problem is that when fused systems were common, there wasn’t as much electrical stuff in homes and fewer individual circuits were needed. These small panels are often stuffed with more circuits than they were designed for, creating unsafe conditions. When older small panels are stuffed full, there’s often a one or more subpanels added to accommodate the additional added circuits.  I rarely find subpanels wired correctly.

Fuse Box

Fuse Box

Branch Circuits
In addition to knob and tube wiring, there can be issues with “newer” types of wiring. Early wiring did not have a ground conductor, just “hot” and “neutral.” Grounding wasn’t required until the 1960s. Think of a grounding system as a safety net of the electrical system. Older wires have been exposed to possible damage and abrasion. Previous changes and remodeling could have caused damage to conductors and connections.

Fixtures, Outlets and Switches
Constant plugging in of all of our electrical and electronic gadgets eventually wears out the contacts in outlets. I sometimes find owners try to create the illusion of an updated electrical system by installing new three-slot, grounding type outlets in an ungrounded system. Switches are subject to wear and mechanical failure. Fixtures are frequently changed by homeowners with no professional electrician training and limited skills.

These are just a few of the more frequent issues with a major system, that when fails can cause severe injury, loss of property and life. Like many old-house plumbing systems, the electrical system usually gets updated in pieces and never quite makes it completely up to current standards.

The most important thing to consider is having the electrical system professionally inspected and any repairs, changes or updates performed by a very experienced, licensed electrician.


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  1. 17 Responses  to “Old House Electrical Concerns”

  2. Maryna
    Oct 21, 2015
    I bought old house year ago. And imagine there are no grounding here. Till now I can't understand how it can be. And also I want to change all wiring system in house. I have never heard that there are so many types of grounding in internet. (I didn't faced it before) and prices on it are different too. I guess it depends from quality. I found obo groundings and as I'm from Belgium it will be very convenient to buy it online. But I don't know - does it worth it? I found this web site http://hardware.be/obo but there are no clear reviews, you can only buy it. Have you ever heard about it?
  3. Dave Thompson
    Feb 12, 2015
    I was redoing my older home last year and had to redo the electrical wiring. I'm so glad I got a professional electrician to work on my home. Thanks for the article and the great tips for those looking to redo there homes. Electrical
  4. Skylar Mitchell
    Feb 10, 2015
    Last year, we moved into an older house, and we have noticed quite a few problems with it. Recently, the problem is the electricity. It doesn't seem to be wired correctly, so certain things don't turn on like they are supposed to. I think it would be best to get it inspected and then possibly rewired. I am sure that if we got it all updated, we wouldn't have to worry about so many problems occurring! http://www.crownelectricltd.ca/en/
  5. Jan 2, 2014
    Unfortunately knob and tube is a fact of life when you buy an older house. The only way to replace it all is to open the walls, especially if it is a 2 story home.
  6. Darren
    Aug 14, 2013
    I have been hiring City Centre Electricians regularly for my handling various electrical needs at my commercial and residential premises, and have always felt satisfied with the promptness in taking actions.
  7. Jake Alexander
    Nov 15, 2012
    I found this article to be very informative and well written. With old homes it is very important to get a plumbing repair man to inspect the home. I would imagine that updating the electrical system can be a very complicated process.
  8. Aug 29, 2011
    I think it's safe to say that a fuse box is inferior. Quite a few homes still have them though.
  9. Aug 29, 2011
    Very good post. Due to GFCI circuits and AFCI circuits Conversion to three wire electrical systems has become necessary. Thanks for the info.
  10. Aug 29, 2011
    Keep the good information coming I will be a regular reader. Thanks
  11. Aug 29, 2011
    The best thing if a homeowner is buying an older house is to get a electrician to survey the electrics and give you a report, this will mean you know exactly what you are getting, no hidden surprises or hidden safety concerns.