How to Install an Outdoor Electrical Outlet

An outdoor electrical outlet.
What You'll Need
Outdoor-rated electrical box with cover
Electrical tester (plug-in type)
20-amp receptacle
Long-nose pliers
Cable with ground
Cable clamps
Clear caulk
Caulking gun
Wire stripper

An outdoor electrical outlet is a convenient feature to have in your home. It makes entertaining, yard work, and lighting up the outdoors much easier. It’s not difficult to do, but as with any project involving electricity, be very careful while working.

Step 1 - Disassemble the Interior Outlet

Decide where you want the electrical outlet to be located on the outside wall of the house. Look inside the house to see where the closest receptacle is. It is easiest to locate the new outlet directly on the other side of the wall from an existing interior outlet. Turn off the power to the interior outlet. Unscrew the cover of the outlet and remove it. Unscrew the two screws on the receptacle. Take the receptacle out of the box and disconnect all of the wires. To remove the electrical box from the wall, remove the mounting screws. Pull the box out and pull it off to the side. Push through a knockout space in the box for the new wiring. Look inside the wall to see if it is clear for drilling from the outside wall.

Step 2 - Drill the Opening

From the outside, drill a 1¼ inch hole that is 5/8 inch deep for the cable clamp to fit into. Now drill a ½ inch hold into the wall from the exterior. Affix a cable to the new electrical box. Then, run that cable through the box and into the wall space. Push the cable end through the knockout in the interior electrical box. Pull through at least one foot of cable past the box and leave it hanging there for now.

Step 3 - Mount the Outside Box

Mount the exterior electrical box to the outside of the house over the hole that was drilled. Pull the cable through the back of the box and put a cable clamp on it. Now caulk in the opening. Put the screws in the box and tighten them down. Now, caulk the outside of the box so no moisture gets between the box and the siding of the house.

Step 4 - Hook Up the Wires

Trim the cable coming out of the exterior box down to 4 inches. Strip away 3 inches of the wire covering. Then, strip off a ½ inch of the covering of the other wires. The black wire should be attached to the gold screw and the white wire attached to the silver screw. Ground the box by wrapping the grounding wire (the copper wire) to the grounding screw. Attach the other end of the grounding wire to the green screw. Put the outlet into the box, apply the gasket, and then put on the cover.

Step 5 - Reassemble the Inside Outlet

Take the new cable from the exterior box from the wall cavity and connect it to the interior box. Put the box back in place. Then, wire the inside wires in the same way. The black wire goes to the gold screw, and the white wire to the silver screw.

Step 6 – Turn on the Power

Now turn on the breaker to these outlets. Use a plug-in style electrical tester to test both outlets. Now test the automatic trip button on the exterior box. It should turn off and the tester should show it has no power. Push the reset button.

You now have outdoor power for plugging in patio lights, using electric tools, or running an extension cord to your holiday lights.