How to Install an Outdoor Outlet: Step-by-Step Guide

Make this project simple by choosing an installation site that’s within the same stud cavity as an installed indoor outlet. Refer to your local building codes for any limitations as to where you can install an outlet. For example, you can’t install an outdoor electrical outlet in the same circuit as an indoor electrical outlet located in the kitchen, bathroom, or laundry room.

Never attempt to install electrical outlets without first turning off the power supply and ensuring there’s no electrical current. Failure to do so could result in electrocution. With this in mind, flip off the power from your circuit breaker and test for live electricity using a voltage tester.

Unscrew the cover plate on your indoor outlet, the outlet itself, and the wires connected to the outlet, then remove it from the wall. Keep the screws in a container for later use.

Put your detective hat on because it’s important that there’s enough room for sliding a new cable through the electrical box inside the wall. If there’s not enough room or you have a metal box, you should replace the box with a larger, plastic electrical box so as not to overcrowd the wires.

First, use a stud finder to make sure there isn’t a wall stud where you plan on drilling or cutting into the wall. With everything cleared, use a 12- or 18-inch drill bit to drill into the wall that’s behind the outlet box until the bit pushes all the way through the exterior of your wall—straight through the siding. Keep your drill positioned at a slightly downward angle to ensure there’s plenty of room inside the wall for both electrical boxes if you plan on installing a recessed outdoor outlet.

Once you’ve made it all the way through, go around to the exterior wall and drill a 3/4-inch hole through the siding to increase the size and make it easier to slide the cable through in the later steps.

If you want your electrical outlet to fit inside the wall, you’ll need to cut into the wall. With the hole from the drill guiding you, place the new outlet box close to the center of the hole. Level the outlet box, then trace it with a pencil. Using a jigsaw, cut out the outline to make space for the new electrical box.

Push a 12/2 wire with a 20-amp circuit through the hole in the wall until you have approximately one foot of cable hanging out on both the exterior and interior walls. Cut the wire from the roll.

Now your outlets are ready to get connected. You can start with either the interior or exterior outlets. In this tutorial, we’re starting with the interior outlet. To rewire the interior outlet using a new cable, double-check that you have at least six inches of cable to work with. Expose the wires to strip 1/2-inch of insulation off the wires with a wire stripper.

Once exposed, loop the black wire with a pair of needle nose pliers and pull it clockwise under the head of the gold or bronze screw you’ll find on the side of the outlet. Be sure to tighten the screw with a screwdriver until the wire is snug.

Repeat the process for the black wire, only this time, you’ll loop the white wire clockwise under the screw head of the silver screw on your outlet. Use a screwdriver to tighten this wire into place.

You’ll also see a copper wire on your cable. This wire grounds your outlet. Connect it to the ground screw terminal and then wrap all of the wires neatly inside the box, securing them with a cable clamp. Reinstall the outlet back into the box.

If you’re mounting an electrical box rather than installing a recessed box, this is where you’ll need to attach the exterior outlet to the wall. Be sure to pull the end of the cable through the electrical box before you screw the mount into the wall. It’s also a good idea to apply 100% silicone sealant to make the hole where the wires come out waterproof in the off chance rain enters the exterior box.

To install the wiring for the GFCI outlet, repeat the same process you used to connect the cable to the indoor outlet. Connect the white, black, and bare copper ground wire to the silver, brass or gold, and green screw terminals, then secure the wires with a cable clamp and tuck them into the box.

With the wires complete, you can now connect the outlet to the exterior box. Use a screwdriver to screw the outlet into the box using the screws that came with your box.

Place the plastic cover over the opening of the exterior box. Make sure it covers the entire outlet and that you’ve placed the hinges of the cover on the top. Placing the cover with the hinges on the bottom allows for the box to pop open and for water to get in during storms. Then, secure the box cover with screws from the kit, and snap the box in place.

With everything complete, now it’s time to turn the power back on and test your handiwork. Plug in a strand of lights to make sure that everything is in working order.