How to Run an Underground Electric Wire

  • Transcript

    LESLIE: Well, if you’d like to add lights to your yard or you have a detached garage, shed or gazebo that needs power, you might be running heavy-duty extension cords to get that electrical source. It’s a quick fix, it’s temporary and it’s not the best solution.

    How to run an underground electric wireTOM: That’s right. Now, if you need to run electricity from your home to another structure, the better option is to install an underground cable. Now, this is a project that you can start yourself, perhaps, to save some money. Here to tell us how to go about it is Scott Caron, the master electrician from TV’s This Old House. 
    Welcome, Scott.
    SCOTT: Hey, Tom and Leslie. Thanks for having me.
    TOM: Hey, it’s our pleasure.
    So, outdoor living is all the rage today, right? And includes improving lighting but it’s an area where electricity and water actually have to mix. And that’s a potentially dangerous combination if you don’t do it right, correct?
    SCOTT: Yes, it certainly is. It’s not a difficult thing to do. However, it has to be done perfectly so that you don’t have a dangerous situation.
    TOM: OK. So probably not a DIY project?
    SCOTT: Partially, Tom. The worst part about bringing power outside is burying the wire and we have to dig a trench to do that, anywhere from 12 to 18 inches deep. That’s where a homeowner can really help out.
    TOM: Yeah. And that’s probably good advice.
    So, where do we begin?
    SCOTT: Well, the biggest thing that a homeowner can do to help save money is digging. And that is usually the first step is to dig a trench from the home to wherever it is that you want the electricity to go, whether it’s a garage or a detached building of some sort or maybe you have an outdoor patio area. That’s the biggest thing and the hole has to be pretty deep – 12 to 18 inches – depending on exactly what you’re doing.
    LESLIE: Scott, I think a lot of times people just want to dig and start working on a project and you hope you find a buried treasure. But more likely, you’re going to find a water pipe or some sort of electrical line. How do you know what’s underneath the ground?
    SCOTT: You have to call 811. It’s a utility-locating service. That will get you a good start. Unfortunately, they don’t always cover the small stuff in the backyard, like your irrigation systems and maybe an old water line that your grandfather ran to a well someplace. But it’ll get you started. And with the small sprinkler stuff, you can usually fix that pretty easily.
    TOM: Now, what kind of cable do we use to run outside? Is that different than the wiring that’s run inside a house?
    SCOTT: Generally, with direct-burial cable, it’s called – it is an encapsulated wiring system or a structure that has everything well protected. So you can put this stuff right in the ground. We like to put a little sand around it as a warning area. So if somebody is digging in the future – and we put a piece of tape on top that says, “Hey. Hold on a second. There’s wires here. Stop digging. Find out what’s going on.” And it helps us out.
    TOM: So this encapsulated cable – if you use it, you don’t have to have the wiring encased in any type of conduit?
    SCOTT: No. Just if you’re coming up out of the ground, it’s a good idea to encase it in this plastic PVC conduit.
    Now, Tom, digging is not my favorite thing. If you’re a homeowner and you know how to use a gas- or diesel-powered trencher, it could be some fun. Had people in the past rent these machines. They’ll dig a trench and it’ll go anywhere they went to go with it, so …
    TOM: So that’s potentially a way to save a little money, save you some aggravation and get the job done.
    SCOTT: It is. Definitely. Yep. 
    TOM: Now, since we’re talking about electricity and water, what special considerations do you have to enable to make sure that there’s not going to be a shock situation?
    SCOTT: Well, if you know a licensed electrician, you can have them looking over your shoulder while you’re doing it but it has to be protected by a GFCI outlet or a GFCI circuit breaker. There’s a couple different ways of doing it but you’ve got to consult with an electrician or have them – maybe buy them a couple beers or whatever.
    TOM: Yeah. Buy them the beer after he does your project.
    SCOTT: Exactly. You’ve got it.
    TOM: We’re talking to Scott Caron. He’s the master electrician from TV’s This Old House.
    So what are some of the common places that folks run these cables for what kind of projects?
    SCOTT: Well, I’ve seen hot tubs put in the middle of their yard. I’ve seen people need power to their garage, either for a small shop or lighting or a garage-door opener. Recently, this past summer, we did an outdoor kitchen, which required a lot of power because they had two refrigerators out there. They had cooktops, they had three or four different types of grills. 
    So, wherever you want to live inside and whatever your needs are inside, generally, they’re taking them outside now. People like the outside. They want to be – have that in their experience in their lives, so …
    TOM: And as you say, there’s a right way to do that. You can pretty much have all the convenience of electricity, whether you are out or in.
    Scott Caron from TV’s This Old House, thank you so much for stopping by The Money Pit.
    SCOTT: Tom and Leslie, thanks for having me. Appreciate it.
    TOM: And This Old House and Ask This Old House are brought to you on PBS by The Home Depot. More saving, more doing.

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