Adding an outdoor outlet can be a useful home improvement project that allows you to plug in and power appliances outside your house. Properly wiring an outdoor outlet is important for safety and functioning. This guide will walk you through the steps of how to wire an outdoor outlet, from gathering materials to connecting wires.
What You’ll Need
Before wiring an outdoor outlet, make sure you have all of the necessary materials:
- Outdoor outlet cover and box
- Weatherproof outlet cover plate
- GFCI outlet
- 12 or 14 gauge outdoor electrical wire
- Weatherproof electrical tape
- Wire stripper
- Voltage tester
- Philips head screwdriver
- Pliers
- Circuit finder
- Wire nuts
- Grounding rod and clamp
Make sure all materials used are rated for outdoor use. The outdoor outlet box should be weatherproof and made of a durable, non-conductive material. The GFCI outlet and cover plate should also be weather resistant to protect against moisture.
Turn Off the Power
Before doing any electrical work, always turn off the power to the circuit you’ll be working on at the main circuit breaker panel. Make sure power is off by testing the wires with a voltage tester. Working on live wires can result in electrocution.
Use a circuit finder to identify which breaker powers the outdoor wall you’ll be installing the outlet on. Turn off that breaker and double check that power is off with a voltage tester.
Install the Outdoor Outlet Box
Mount the outdoor outlet box centered at least 12 inches above the ground. The box should be securely attached and level.
If installing on siding, cut a hole slightly larger than the outlet box. Place the box in the opening and attach with galvanized nails or screws. Seal any gaps with silicone caulk.
For masonry walls, chisel out a section slightly bigger than the box. Place the box in the opening and use masonry anchors to secure it. Apply mortar around the edges to hold it in place.
Make sure the open side of the box faces downward so moisture doesn’t collect inside.
Run Electrical Wires
Run 12 or 14 gauge outdoor electrical wiring from the main circuit panel to the outlet box. Use the shortest path possible. Secure the cable to studs using staples at least every 4 1/2 feet.
Use wire strippers to remove 3/4 inch of the outer plastic sheathing from the end of the cable. Next, strip 1/2 inch of insulation from the ends of the white neutral wire, black hot wire, and bare ground wire.
Connect Wires
Insert the electrical cable through the outlet box clamp to secure it. Carefully connect each wire to the matching terminal on the outlet:
- White wire to silver neutral terminal
- Black wire to brass hot terminal
- Bare wire to green grounding screw
Use pliers to tightly loop the wires clockwise around the screws.
If your outlet has a backwire configuration, insert the wires into the corresponding holes in the back and secure them by tightening the screws on the sides.
Make sure no copper is exposed. Secure the grounding wire to the green grounding screw on the outlet.
Install the GFCI Outlet
Install a GFCI outlet for outdoor outlets for added safety. This protects against electric shocks and electrocution.
Connect the outlet’s LINE terminals to the electrical wires:
- Black wire to hot brass terminal
- White wire to neutral silver terminal
Do not attach wires to the LOAD terminals unless you want to protect additional outlets on the same circuit.
Push any excess wire back into the box to tidy it up. Screw the outlet securely into the box and install the weatherproof cover plate.
Add a Grounding Rod
Grounding helps prevent shocks, fires, and damage from lightning strikes. Drive a grounding rod at least 8 feet into the ground near the outlet.
Attach a grounding wire from the rod’s clamp to the outlet’s grounding screw. For better conductivity, pour water over the grounding rod.
Test and Finish Up
With the power back on, plug in a lamp and test that the outlet is functioning properly. Make any wiring adjustments needed until it works correctly.
Seal any openings or gaps in the outlet box with silicone caulk to keep moisture out. Put on the weatherproof outlet cover. Visually inspect that all connections are secure.
Periodically check that the outlet has not become loose or damaged, especially after severe weather. Test the GFCI with the test and reset buttons to ensure it’s providing protection from shocks.
By following these instructions, you can safely add an outdoor outlet. Always turn off power before wiring. Take precautions against moisture. Have a professional electrician do any electrical work if you’re uncomfortable with the steps. With the proper materials and safety measures, you can get powered up outside your home.
Choosing an Outdoor Outlet Location
Picking the right spot is an important first step when adding an outdoor outlet. Consider these factors when deciding where to place it:
Convenience
The outlet should be located somewhere convenient to plug in lights, tools, sprinklers, holiday decorations, or other outdoor appliances. Think about your needs when determining the placement.
Distance from Power Source
Position the outlet close enough to the indoor power source so wire runs are short. Long wiring distances can result in safety hazards and voltage drops.
Visibility
Choose a visible location to easily access the outlet, but avoid spots where the outlet box can get damaged by lawn equipment.
Height
Mount the outlet box at least 12 inches above ground level to avoid moisture issues. The cover plate opening should face downward.
Protection from Weather
Overhangs like eaves and awnings help shield the outlet from rain, snow, and splashing. Place it somewhere with this protection.
Not Near Water Sources
Don’t position it directly next to sprinklers, pools, or hoses where it could get wet, causing electrocution and shock risks.
Clearance
Allow open space around the outlet without any obstructing objects. You’ll need room to safely plug in devices.
Avoid Low Spots
Don’t place it in low areas that can collect water. This exposure can damage the outlet or cause short circuits.
With planning, you can determine the ideal spot based on your specific needs and installation location.
Outdoor Outlet Box Types
Choosing the right outdoor outlet box is important for safety and durability. Look for boxes designed for outdoor use when wiring an exterior outlet. The box should have these features:
Weatherproof Design
It must be resistant to moisture, rain, snow, and splashing water. Weatherproof boxes are sealed to prevent water seeping in.
UV Resistant
For longevity, the box should be made of UV-resistant materials so the sun’s rays don’t damage or degrade it.
Non-Conductive
The box should be made of plastic, fiberglass, or other non-conductive material. This prevents shocks and electrical shorts.
Extra Space
It should have adequate interior space for making wiring connections and installing the outlet and cover plate.
Mounting Holes
The base should have pre-drilled corner holes for stable surface mounting using screws or anchors.
Cable Opening
A knockout hole allows the electrical cable to enter through the base of the box into the interior space.
Grounding Terminal
It must have a place to attach a grounding wire for added protection against stray electrical current.
The box style you need depends on your installation type – flush mount, recessed, or surface mounted. Choose the right one for your situation.
Choosing an Outdoor Outlet Cover
The outlet cover plate should also be rated for outdoor use. It must seal out moisture. Consider these factors when selecting:
Weatherproof Rating
Verify it has an outdoor weatherproof rating like “in-use” or “wet location.” This confirms it seals when plugs are inserted.
UV Resistant
Covers made of UV-resistant polycarbonate, thermoplastic, or metal last longer outdoors.
Style
Pick a style compatible with your outlet box. Common options are vertical plates, horizontal plates, or extra-duty covers.
Number of Openings
Get a cover plate with the correct number of openings for the installed outlets and any required blank spaces.
Gasket
Rubber gaskets around the openings help keep moisture out when plugged in or empty.
Mounting Screws
Stainless steel cover screws won’t rust from moisture. They should tighten securely.
Listed Rating
Look for markings like “UL Listed” to confirm testing and safety certification.
The cover plate opening should point downward so water can’t collect inside. Confirm it’s compatible with your chosen outdoor outlet.
Selecting an Outdoor Electrical Wire Gauge
Choosing the proper gauge electrical wire is important for safety and adequate power delivery. Follow these tips when selecting:
Wire Type
Use only wiring approved and listed for outdoor use, such as NMB or UF-B cable. The insulation is designed to resist moisture and sun exposure.
Wire Size
For an outdoor outlet circuit, choose 12 or 14 gauge wire for sufficient power delivery. Larger wire gauges allow more current.
Stranded vs Solid
Stranded wire is more flexible for working outdoors. Solid wire can become brittle when exposed to weather extremes.
Insulation Thickness
Thicker plastic insulation better withstands abrasion and moisture penetration outdoors.
Copper vs Aluminum
Copper wiring handles outdoors better. Aluminum can oxidize when exposed to water and air.
Color Coding
Use white for neutral, black for hot, and green or bare copper for ground. This helps identify wire functions.
Verify your outdoor electrical wiring is properly rated and sized for the outlet amperage, voltage, and circuit run length.
Wiring an Outdoor Outlet from Indoor Power
Running wiring from indoor power sources is the most common way to supply electricity to outdoor outlets. Follow these guidelines when wiring outdoor outlets this way:
Shortest Route
Take the most direct path from the interior panel to the exterior outlet location to minimize wire needed.
Straight Shot
Run the cable out in a straight line without bends for easiest pulling. Make a hole just big enough for the wire to fit.
Use Existing Openings
Run the cable through existing openings in the wall to avoid unnecessary holes. Use caulk to seal openings.
Avoid Moisture
Keep the outdoor portion as high up on walls as possible to prevent wetness from seeping into the interior.
Use Protection
Secure the wire firmly along the run and protect it from damage. Use nail plates when passing through studs.
Watch Live Wires
Turn off the power at the main breaker panel before splicing wires. Don’t work on live wires to avoid shocks.
Match Wires
Connect like-colored wires when splicing: white to white, black to black, green to green. Keep connections dry.
Follow Codes
Adhere to all electrical codes for outdoor wiring specifications. Consider having work inspected.
With proper materials and safe installation, you can successfully run power from indoor sources.
Using a GFCI Outlet vs Breaker
GFCI protection is vital for outdoor outlets to prevent lethal shocks and electrocution from electric current flowing through water. You have two options:
GFCI Outlet
GFCI outlets have built-in protection that quickly cuts power when a ground fault occurs. Install a GFCI outlet in the outdoor location wired from an indoor non-GFCI circuit.
GFCI Breaker
A GFCI breaker provides protection to the entire circuit. Have an electrician install a GFCI breaker in your main panel for the circuit, then use a standard outdoor outlet.
Which is Better?
Outdoor outlets wired with a GFCI breaker cost less because standard outlets are less expensive than GFCIs. They also don’t require resetting after tripping. However, GFCI outlets offer more convenience and localized protection. One outlet can trip without cutting power to other outlets on the same circuit.
Test Regularly
Test GFCI outlets and breakers monthly by pressing the “Test” button to confirm they trip and cut power when functioning properly.
Installing GFCI protection is a necessary safety precaution for outdoor outlets. Decide whether GFCI outlets or breakers work best for your situation.
Installing a Weatherproof Box on Siding
Mounting an exterior outlet box on siding like vinyl, wood, or fiber cement requires extra care to make sure it seals tightly and remains attached securely. Follow these tips when installing:
Choose Appropriate Box
Pick a weatherproof outlet box designed specifically for mounting on siding. It should have a flat base that sits flush on irregular surfaces.
Make Precise Cutout
Use a sharp hole saw to cut a hole exactly matching the dimensions of the outlet box. Test fit to ensure it sits flush with the siding.
Caulk Perimeter
Run a bead of silicone caulk around the back edge of the box to seal it when set into the siding cutout.
Anchor Securely
Use exterior-grade screws long enough to penetrate the wall sheathing. Tighten firmly so the box remains secure.
Fill Gaps
Caulk around the entire exterior edge of the box and siding seam to prevent moisture intrusion into the wall.
Weatherproof Cover
Install an extra-duty in-use cover plate suitable for siding installation. It should completely seal outlets.
Check Condition
Periodically verify caulk and cover seals remain intact after exposure to weather. Reapply caulk if any gaps appear.
Take steps to prevent moisture problems when mounting on exterior siding. A securely installed box and weatherproof components keep electricity flowing safely.
Wiring Multiple Outdoor Outlets
Having multiple exterior outlets around your home provides convenience for plugging in outdoor appliances and lights wherever needed. Here are some tips when wiring several outdoor receptacles:
Plan Layout
Determine the number of outlets and their locations based on your outdoor power needs for tools, lighting, electric grills, etc.
Dedicated Circuit
Use a dedicated 15 to 20 amp outdoor circuit to supply all the exterior outlets, not just one.
GFCI Protection
Protect the circuit with a GFCI breaker or outlet. Follow local codes for requirements.
Use Boxes
Install weatherproof boxes designed for daisy-chaining together multiple outlets.
Link Wires
Connect wires in parallel, not series, to evenly distribute power to each receptacle.
Use Junction Boxes
Include outdoor-rated junction boxes where necessary for splicing wires.
Avoid Overloading
Do not exceed the circuit’s capacity. Consider a 20 amp circuit for multiple outlets and high loads.
Follow Codes
Adhere to all electrical codes for the number of outlets permitted per circuit.
Multiple outdoor outlets must be wired safely. Planning the layout and properly distributing power prevents overloads and tripped breakers.
Adding an Outdoor Outlet to a Masonry Wall
Outdoor outlets on brick, concrete, stone, and stucco walls require some specialized considerations during installation. Follow these guidelines when wiring an outlet on a masonry wall:
Choose Masonry Box
Use an outlet box designed for masonry installation. It should have adjustable mounting lugs to set the box flush within the wall.
Chisel Precise Opening
Chisel out an opening in the masonry for the box. Make it just large enough for the box to fit flush inside. Avoid making it too big.
Mortar In Place
Insert the box and use mortar around the edges to hold it firmly and seal it within the opening. Allow it to fully cure before using.
Caulk Around Edges
Also apply caulk around the exterior seam between the box and masonry for extra moisture protection.
Use Longer Screws
Secure the outlet tightly with long, masonry-rated screws that can penetrate the brick or concrete.
Attach Ground Wire
Connect the ground wire to a grounding rod buried in the soil. The earth provides a safe path for stray current.
Weatherproof Cover
Use an in-use rated, gasketed cover. The gasket helps seal the outlet when plugs are inserted.
Check your electrical codes for any requirements specific to your area. Masonry walls need weatherproof boxes and outlets secured and sealed properly.
Wiring an Existing Outdoor Outlet
If you have an outdoor receptacle that’s already wired and you want to upgrade it or add new wiring, take the proper precautions. Here are tips for safely wiring an existing outdoor outlet:
Turn Off Power
Switch the circuit breaker to the outlet off at the main panel. Use a contactless voltage tester to confirm power is off.
Test Existing Wires
Before touching any wires, always test them with a voltage tester to be sure power is off. Don’t assume they’re dead.
Inspect Condition
Check if the existing wires or receptacle show any signs of damage from moisture or aging. Replace damaged components.
Review Wire Colors
Note which wire is hot, neutral, and ground according to the color coding: black, white, and green.
Remove Old Outlet
Unscrew and detach the existing receptacle from the outlet box. Carefully pull the wires out from the box.
Clean Box
Remove any dirt or debris accumulated in the outlet box so wires make flush contact.
Splice New Wires
Connect any new wiring to existing wires using proper splices and wire nuts rated for outdoor use.
Install GFCI Outlet
Replace the old outlet with a new GFCI receptacle rated for outdoor use. Connect wires securely.
Test Operation
Verify proper function before leaving. Press the “Test” then “Reset” buttons on the GFCI to confirm it works.
Use caution and test all wires when modifying existing outdoor outlets. Check conditions and upgrade to new weatherproof components.