When it comes to using electrical devices outside, we want our friends and family to be safe – especially in the rain or near water sources. In this context, it’s assumed that most modern homes are fitted with appropriate outdoor outlets – but they aren’t. And the ones that are fitted might need to be upgraded too.
Building code stipulates that all new homes must have outdoor outlets fitted with a Ground Fault Circuit Interrupter (GFCI). Although this code doesn’t cover old houses, upgrading your older home with these life-saving devices is a good idea.
We’re going to give you some instructions on why your home needs a GFCI outdoor outlet in this article – and how to fit one. However, if you’re unsure about doing this then please seek professional help.
Is There An Outdoor Electrical Outlet Fitted On Every Home?
Most new homes have at least a couple of outdoor electrical outlets. But these aren’t just any old outlets. These are GFCI ones.
Electricity and water mix in a bad (shocking, haha) way. The trouble is that water is a great conductor. To protect outlets where water might be present, a special outlet is needed.
A ground fault is a fault, caused by old wires, chewed wires or accidents, that causes a spike of current to run to the ground. Often, water helps the spike of electricity travel. A GFCI outlet compares electricity coming into the device with electricity going out.
If the two are even 4 milliamps different (like when a spike occurs), then the device shuts down the power. A GFCI (ground fault circuit interrupter) outlet can shut down power in one thirtieth of a second. Human muscles freeze up (you won’t be able to let go) at 10 milliamps.
A GFCI outlet looks distinctive – it is rectangular, and it has two buttons that pop in and out. One of the buttons allows you to test the outlet (they do wear out). The other button indicates that a fault has occurred.
In the 1970s, GFCI outlets were required around pool areas. In 1975, code added that GFCI outlets needed to be in bathrooms. Since then, code specifies that GFCI outlets needed to be in all areas where there might be moisture – crawl spaces, garages, kitchens, boathouses, unfinished basements, wet bars and – outside.
Specifically, code requires GFCI outlets within 6 feet of the outside edge of a sink or water source. All bathroom outlets must be GFCI. All garages located at or below grade level must have GFCI. All unfinished basements must have GFCI receptacles.
Code says that every outdoor outlet must be GFCI. Although this code is for new homes – not old ones – upgrading your old home with these life-saving devices is a good idea.
How To Install An Outdoor Outlet
You will need:
- A GFCI electrical box. This box will be mounted on the outside of your house, so choose one that is attractive.
- A couple of feet of NM-B cable
- Wire nuts
- Wire strippers
- Electrical tape
- Drill with 1/4 inch bit and 3/4 inch bit.
- A multimeter
- An outdoor rated GFCI outlet with a waterproof cover or gasket. This should fit on your GFCI electrical box and it should be attractive.
- Exterior grade silicone caulk
Here are the steps to install an outdoor outlet:
- Locate a good place for your outdoor outlet. A covered spot is best, like under a patio roof. Then, go inside. Look for an inside outlet in the spot where you want the outside outlet. Take the switch cover off. Outlet boxes are mounted to studs. The new outside outlet should go on the same stud, on the same side.
- Turn off the circuit for that inside outlet. Check with a multimeter to be sure there’s no power.
- Unscrew the mounting strap screws (or retaining screws). Here’s a good diagram.
- Gently pull it out of the outlet box.
- Disconnect the circuit wires. You can bend them out of the way or cover the ends with caps or electrical tape temporarily.
- You need to run a cable through the back of the box. Many electrical boxes have holes or knockouts. If your box doesn’t have a hole, remove the box knockout. This is a metal or plastic tab or indentation at the back of the electrical box. Put a screwdriver against the knockout and tap it gently with a hammer until the button pops off and you have a hole.
- Drill a hole through the wall to the outside. You can drill the hole through the knockout to the outside if you can. Use a 1/4 inch bit.
- Go outside.
- Enlarge the 1/4 inch hole to 3/4 inch.
- Cut 1.5 feet of NM-B cable and feed it from the outdoor box to the indoor one. Make sure the 1.5 foot of cable is secured using the clamp on the box or a push-in cable clamp. Trim the NM-B cable so that only about 6 inches is sticking out from the wall, otherwise it will be too hard to jam it into the box.
- Go inside. Cut an additional length of NM-B cable, about 6 inches long. This is the pigtail.
- Strip the outer sheathing from the pigtail. Then, peel the cable apart so you have three separate, coated wires. Strip 3/4 inch of the inner sheathing, exposing the bare wires. Install these wires to the outlet. Use a pair of pliers to bend the ends of the wires, so they will wrap around under the screws. Screw the black wire to the gold terminal, white wire to the silver terminal on the opposite side and the ground to the green screw.
- Inside, match up the pigtail wires (that you just attached to the outlet), the 1.5 foot cable wires (sticking out of the wall) and the original house wires (also sticking out of the wall). There should be three of each color. Match up black to black, white to white and ground to ground. Put all three blacks together, twist them, and cover with a wire nut. Put all three whites together, twist them, and cover with a wire nut. Match up all three grounds, twist them together and cover with a wire nut. Add a small piece of electrical tape to the bottom of each wire nut to keep it from coming loose. (Note: if you have a wire box, you may need to cut an additional pigtail to connect it to the box’s ground screw).
- Gently push all the wires back into the box and screw the retaining screws back in. Put the switch cover back on.
- Go outside with your new outdoor GFCI box, GFCI outlet and cover. Knock out the knockout from the new box. Feed the 1.5 foot cable through the hole. Holding the box next to the wall, clamp the cable using the box’s clamp or a push-through clamp.
- Glue the new outdoor electrical box to the outside of your house, then reinforce it with some exterior grade screws.
- Trim the NM-B cable so that only 6 inches stick out from the side of the house. Cut or pull apart the 6 inches from the outer sheathing of the cable, leaving three coated wires. Strip 3/4 inches from the ends of each coated wire, exposing the bare wires.
- Connect the new GFCI outlet. Watch an instructional video first. First, unscrew the terminals. Make sure the exposed ends of the wires are straight. Then, push the black wire to the black slot under the LINE screw (the terminal may be gold or brass), the white wire into the silver terminal and finally the copper ground to the green ground terminal. Make sure you push the wires fully into the slots and then screw them down tight.
- Carefully push all the wires into the box and screw in the GFCI outlet. You may have a GFCI gasket for waterproofing. Install that now.
- Finally, turn on the breakers and test the outlets with your multimeter. Check that the GFCI box does reset properly.
In this video, they flush mount the outside electrical box, but otherwise, the steps are the same.
Do Outdoor Outlets Need To Be On Their Own Circuit?
Nope. You can add an outdoor outlet to an existing outdoor or indoor circuit, if it can handle the additional energy demand. But, they do need to be protected with a GFCI breaker.
Do Outdoor Outlets Need To Be Covered?
Yes. Even under a porch cover. Outside there’s dew, hoses, wading pools, bowls of dog water, salt air, blowing rain, blowing snow, hot tubs, slip n slides, patio furniture washing, patio washing, and more.
We checked online and most GFCI outdoor covers cost under $20. Just. Do. It.
How To Get Power Outside Without An Outlet
Use an outdoor-rated extension cord for a temporary solution. Plug the outdoor extension cord into a GFCI outlet inside, then run it outside.
Extension cords are more delicate than you might think and one size DOESN’T fit all. Don’t use indoor extension cords outside. Outdoor-rated cords have much tougher plastic sheathing to withstand temperature drops and UV rays.
Of course, for all you off-gridders, you already have a solar solution.
If you need to fit your own outdoor outlet – then this article should definitely help.
However – we must issue a disclaimer here too – if you don’t feel confident doing this yourself, or have never worked on anything remotely like this before – then we’re duty bound at Take a Yard to advise you to get a professional electrician to do it for you.
After all, you want this done properly and safely – so what’s a few bucks to get this right? 🙂
Homeowner and property investor Larry James founded Take a Yard in 2020 to bring you the very best outdoor living content, based on his years of experience managing outside spaces. Read more >