How To Run Electrical Wiring To An Outdoor Shed?

Don't use an extension cord to get electricity to your outdoor buildings. Here, we'll show you how to wire a shed the right way.

Time                   Complexity               Cost

A full day          Intermediate          $101–250

Introduction

A backyard shed frees up garage space, but unless you power them, their utility is limited. Why not add an electrical circuit? It's a good day's work, but the rewards are many, especially if you're running extension cords across your yard or fumbling around in the dark looking for lawn equipment. No more bruised shins and stubbed toes!

The most confusing thing about running outdoor underground wire is the burial depth. The National Electrical Code (NEC) sets these rules, outlined in table 300.5(A)—and boy, is that table a doozy. Depths range from 4 to 24 inches, and how deep you have to dig depends on the wiring method (direct burial cable, conduit or type of circuit) and the location of the buried wire (everywhere from under your driveway to an airport runway).

Luckily, if you're running a residential branch circuit rated 120 volts or less, protected by a 20-amp (or less) ground-fault circuit interrupter (GFCI), the NEC makes your choice easier. You have several options, but rigid metal conduit (RMC) has the shallowest burial depth (6 inches). Underground feeder cable (UF) is next, with a 12-inch requirement. For this project, we went with RMC, which is more expensive than UF but saves tons of labor on digging. (Of course, you can rent a trencher if you don't want to futz with the conduit.)

Keep in mind that these depths apply to wires run under your yard. Wires under concrete patios, slabs and driveways have different depth requirements. Also, if you're looking to heat and cool your shed, or think you might want to expand later, you'll need a subpanel instead of a single 20-amp circuit. Consult your local electrical inspector or a licensed electrician for more info.

- Tools Required

1-in. drill bit

4-in-1 screwdriver

Drill bit set

Drill/driver - cordless

Hacksaw

Pipe wrench (2)

Pliers

Spade

Tape measure

Torpedo level

Wire stripper/cutter

- Materials Required

Duct seal

Electrical boxes

Electrical tape

EMT (electrical metallic tubing)

Fish tape

Fittings (connectors and LBs)

GFCI

Leather gloves

Mattock

Pipe bender

RMC (rigid metal conduit)

Stranded electrical wires

Switch

Two (white and black) conduit straps

Wire connectors