Installing An Outdoor Electrical Outlet

You can install an outdoor outlet yourself if you have confidence in your ability to work with electricity. Your outlet will connect to the nearest inside outlet, so  the location of your outdoor outlet should be as close as possible to the existing indoor outlet.

What you will need to install an outdoor outlet:

  • 2 single gang boxes with threaded connections for electrical conduit.
  • 1/2 inch conduit. (it resembles thin pipe and is designed for electrical wire to pass through)
  • 90 degree elbows for conduit. (usually 5 per pack)
  • Connectors for conduit. (also usually 5 per pack, used to connect conduit to gang box)
  • Hacksaw. (for cutting conduit)
  • Electrical wire. (usually 12 or 14 gauge for residential use) You must use the proper gauge of wire. Look at the circuit breaker that controls the inside outlet from which you intend to run the outside outlet. A 15 amp line will require 14 gauge wire, but a 20 amp line must use at least 12 gauge wire. Wire is thicker as gauge numbers decrease.
  • Wire cutter/stripper. This is used to cut wire and remove insulation from the ends for connecting wires to outlets.
  • 5/8 inch SDS drill bit. This will be used to drill a hole through the wall for the conduit to pass through. It must be long enough to pass through the wall.
  • Silicone sealant. This will be used to seal around the perimeter of the outside outlet to avoid leaks.
  • Outlet cover (optional). This can be used to protect outlet from wet conditions.
  • GFCI (Ground Fault Circuit Interrupter) outlet. This is an outlet for use in damp conditions, and will shut off when it detects fluctuations in electric current.

Installing the outlet

To install the conduit from the inside to the outside outlets, you should replace the inside outlet box with one of the threaded gang boxes. This will allow a seamless line of protective conduit between the outlets.

First, turn off the breaker to the existing inside outlet. If you are unsure of the correct breaker, plug an appliance into the outlet and begin turning off breakers. When the appliance stops, the correct breaker has been found.

Remove the inside outlet from the wall by removing the cover plate and the 2 screws that hold it inside the existing box. Remove the wires from the outlet with a screwdriver, and then remove the box (it may either be nailed in or screwed).

Use your SDS drill bit to drill a hole through the wall. It may take some time with a regular drill, especially if you are drilling through thick masonry or brick. When the hole is complete, insert conduit from the outside to the location of the inside outlet box. Attach a conduit connector to the end of the conduit with a screwdriver, and then screw the connector into the back of one of the threaded gang boxes. When the conduit is connected, place the box inside the wall cavity and secure it with screws or nails.

Cut the conduit from the outside, approximately one inch from the wall. Run the end of your wire through the conduit from inside the house. Depending on your intended location, measure and cut the wire and conduit to reach the destination point. Be sure to cut the wire a few feet longer than you think you need.

Add elbows and connectors as needed to change direction of the conduit, pulling the wire through as you add each additional piece. Next, screw a connector into the second gang box, and screw the box onto the outer wall. Your wire should be protruding from the gang box. Cut the wire until only a few inches remains.

Attach the original wires and the added wires to both sides of the inside outlet (black wires to gold screws, whites wire to silver screws, and green or copper to green screws). Screw the outlet into the indoor gang box, and restore the cover plate. Strip the insulation at two inches from the ends of the outside wires and attach them to the top half of the GFCI outlet (it says LINE as opposed to LOAD).

Apply silicone sealant around the perimeter of the outside gang box. You may choose either to install a cover plate or add a protective plastic cover, which can protect the outlet from the elements. The cover models may vary in installation, but they usually snap on or screw into place.

When you are ready, flip on the circuit breaker. You may see a light on the GFCI outlet. Simply push the reset button in the center. If the light doesn't reappear, you are ready to use your new outlet.

If you are not experienced or confident working with electrical wiring, it may be best to hire a professional, like those at Williams Electric Supply, to perform this service for you. It's a simple task for a professional and should not take too long.