Q: I’m building a new home and wondering if I can install all the electrical wiring myself. It’s not a big home, but it’s got all the things going on you’d normally have in a home, including quite a few three- and four-way switches. I’ve watched a bunch of online videos, I’ve read a few authoritative books and I’m feeling pretty confident. What am I missing? What would you do if you were me?
A: I don’t know that I’ve ever read where a person drowned in their home because of a leaking pipe. But dig deep into the national news and you’re sure to find stories of people and pets dying in house fires that were traced back to electrical causes. So if you decide to install electrical wire, you’re indeed playing with fire.
That said, I don’t want to dissuade you from trying. Every master electrician out there started out not knowing which colored wire nut to use when. A homeowner can successfully and safely install electric wiring in a residential project with some sound advice, an assist from an electrician and a healthy dose of common sense.
The real challenge is doing the work so it meets or exceeds the complex National Electrical Code (NEC), a collection of hard-earned safety standards authored by the National Fire Protection Association.
Let’s start with the size of the conductors, or wires, inside electrical cables. A spool of cable is what you’ll find at your local home center, and in the U.S., it usually contains two insulated wires and an uninsulated, bare copper ground wire.
The NEC requires that certain circuits in the house be fed with wires that can handle a maximum amperage. For example, circuits near kitchen countertop, where appliances are plugged in, need to handle 20 amps. An electric clothes dryer almost always calls for a cable that can handle 30 amps. Your electric stove/oven may need 40 or 50 amps. Other outlet circuits throughout a house can be 15 amps, according to the NEC.
Things you might not even consider will also come into play. For instance, the location of the drilled holes in wall studs and floor joists is critical, because you don’t want drywall screws or finish trim nails puncturing your cables. Knowing how many cables can be stacked on top of one another when nailed to a wood stud is important, too.
You’ll need to know how many conductors, or individual wires, are allowed inside certain electrical boxes. The NEC covers the cubic-inch volume of boxes as it relates to the number and size of the conductors. Some modern boxes have the maximum count printed on them.
Wiring for three- and four-way switches isn’t too much harder than standard types, but you will need to understand how it all works. A few years ago, I recorded two videos on how to wire a three- or four-way switch, which you can watch at AsktheBuilder.com.
You’ll need to fully understand the different circuit breakers that are required by the NEC. I clearly remember when the ground-fault circuit interrupter (GFCI) breaker was added to the code a few years ago. Not only are you required to use a GFCI breaker in certain wet locations, but the NEC also requires an additional arc-fault circuit interrupter (AFCI) breaker on many other circuits.
Here’s my advice: Seriously consider hiring an electrician who will allow you to do the mundane work (such as nailing up the boxes and running the cables between them) and let you connect many of the switches and outlets after the drywall is up. But allow the electrician to do all the truly complex aspects that can only be learned through years of experience.
Tim Carter has worked as a home improvement professional for more than 30 years. To submit a question or to learn more, visit AsktheBuilder.com.