Overview: A simple wiring technique
Most homes have only two exterior outlets—one in
the front and one in the back. That may be OK
most of the year, but it's a real hassle when you're
hanging holiday lights. It can be dangerous, too: Overloading cords
or outlets poses a fire hazard, while crisscrossing your driveway and
sidewalk with cords creates tripping hazards.
In just a few hours, you can solve these problems forever by
adding an outlet or two. In this story, we'll show you how to do just
that. We've made adding an outlet as easy as possible—simply
connect new wire to an existing interior outlet and install your
new outlet on the opposite side of the wall. This eliminates the
arduous task of fishing wires through finished rooms. To bypass
the hassles of cutting a boxed-size hole in the exterior wall,
mount the new outlet right to the siding.
Even if you've never worked with electricity before, you can
do this. Our Web site covers all of the basic skills you need to
complete this project safely (visit thefamilyhandyman.com).
Everything you need is available at home centers for less than
$60. Call your local inspections
department to apply for a permit before you start.
Step 1: Choose and mark the outlet location
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Photo 1: Drill through the exterior wall
Drill a 1/4-in. hole alongside an existing electrical box to
mark the location of the new outlet. Go outside and drill a
3/4-in. hole in the siding over or near the smaller hole.
To keep this project simple, place the new outlet in the same stud
cavity as an existing indoor outlet. Start by choosing the interior
outlet you want to use. Building codes prohibit tapping into circuits
in the kitchen, bathroom, laundry room or into those dedicated
to a large appliance, like a refrigerator. You can use living
room, bedroom and basement circuits, but don't tap into a circuit
that's already overloaded and trips the circuit breaker. To
place the outlet somewhere other than opposite the interior outlet,
see “Running Cable From
Other Power Sources” below.
Turn off the circuit breaker
controlling the outlet. Use a
noncontact voltage tester
to be sure the power is off. Then
unscrew and pull the receptacle
out of the electrical box. Hold
the voltage tester over the terminals
to double-check that the power is
off. Next, unscrew the wires from the outlet.
Make sure the junction box is large enough
to hold an added set of wires. (An overstuffed box
is a fire hazard.) If the box is plastic, shine a flashlight
inside and look for a volume listing, such as 21 cu. in. (cubic
inches). If your box is metal, we recommend
that you replace it (see “Replace an Electrical Box,”
below). Most metal boxes are too small to hold additional wires.
Use a stud sensor to determine which side of the electrical
box the stud is on. Place a 1/4- x 18-in.-long drill bit along
the outside of the electrical box on the side away from the stud.
Squeeze the bit between the box and the drywall. But don't
worry if you make a small hole in the drywall. You can hide it
later with the outlet cover
plate. Drill through the
wall and through the siding
to mark the location
for the new outlet (Photo
1). We tilted the drill bit
downward to lower the
outlet location (if it's near
the ground you can hide it behind shrubs), but you can place it
anywhere on the wall.
Find the marker hole outside and place the exterior junction
box over it on the siding. If that's not where you want it located,
move it straight up or down (staying in the same stud cavity)
and mark the position of the box hole on the siding. Then
drill a 1-in. hole over the smaller hole or the mark on the siding
to make room for the cable.
If drilling through stucco, you'll probably wreck the bit, but
you'll get through the siding. For brick, use a masonry drill bit
with a hammer drill. Then drill a series of small-diameter holes
around the marker hole and knock out the center with a hammer
Figure A: Run a cable from a basement
Figure B: Run wires inside conduit
Running Cable From Other Power Sources
If you don't want your exterior outlet
location limited to where you have
interior outlets, you'll have to tap into
another electrical circuit. If you have
an unfinished basement, you can tap
into a junction box in the basement
and run the cable out through the rim
joist. This is even easier than tapping
into a main floor outlet. Plus, it allows
you to put your new outlet anywhere,
not just opposite an interior outlet.
Simply drill a hole through the rim
joist and siding, then run a cable from
a basement light fixture to the outlet
location (Figure A).
A second option is to run wires
inside 1/2-in. metal conduit from an
existing exterior outlet to the new
location (Figure B). The conduit can
wrap around corners with a service
ell, but don't run it in front of doors.
Plant flowers or shrubs in front to
Turn off the power at the
main panel, remove the
cover plate and outlet,
and use a noncontact
voltage tester to
power is off.
If you have aluminum wiring,
call in a licensed electrician who
is certified to work with it. This
wiring is dull gray, not the dull
orange that is characteristic
of copper wire.
Step 2: Run cable between the outlets
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Photo 2: Pull in the new cable
Cut off 2 ft. of sheathing and two wires from the cable.
Tape the remaining wire to the sheathing, then feed the
loop through a knockout in the interior box. Fish for the cable
from the exterior hole using a hook made from wire. Pull the
cable through the hole.
The new wire must be the same gauge (thickness) as the wire
already in the box, which is most likely 14 gauge but could be
12. To check, use the labeled notches on wire-stripper pliers.
Run cable from the interior box to the hole in the exterior.
Start by removing a knockout in the box by hitting it with a
screwdriver. Then strip about 2 ft. of sheathing off the end of
the cable and cut off two of the three wires. Tape the end of the
remaining wire to the end of the sheathing, forming a loop.
Feed the loop through the knockout into the wall cavity.
Bend the end of a wire coat hanger to form a hook. Insert it
through the hole in the exterior, grab the wire loop in the wall
and pull it back through the hole (Photo 2). Pull through at
least 12 in. of cable to give yourself plenty to work with.
Photo 1: Cut the nails that fasten the box to the stud
with a hacksaw blade. Pull out the box and loosen
the clamps that hold the wire.
Photo 2: Enlarge the wall opening for a remodeling box.
Feed in the new and old cables, then mount the box.
Caulk any gaps between the box and the wall.
Replace an Electrical Box
If your existing electrical box isn't large enough to
hold more wires, you'll have to replace it. Remove
the old box before cutting a large opening for the
new one. This allows you to see if anything is
behind the wall before you make the cut.
To swap out boxes, cut the nails that hold the
box in place (Photo 1). Then remove the box.
Replace it with a plastic “remodeling” box. These boxes have wings that flip
up and attach to the back side of the drywall or
plaster. Hold the box over the wall opening and
trace around it. Then enlarge the opening with a
drywall saw. Don't overcut; you want a snug fit.
Feed the new cable from the outlet being added
into the box before installing it (Photo 2). Wrap the
cable with electrical tape where the sheathing
meets the exposed wires so the sheathing will
slide into the box easier.
Step 3: Wire the interior outlet
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Photo 3: Rewire the existing outlet
Strip 12 in. of sheathing from the cable in the interior
box. Strip 3/4 in. of insulation off the ends of the wires.
Fasten the pigtail wires to the outlet, then join the wires with
At the interior box, cut the cable so there's 12 in. sticking out,
then remove the sheathing to expose the wires. Cut 6-in. pieces
of wires from the coil and strip 3/4 in. of insulation off the
ends. Screw these short pieces to the outlet: The bare copper
goes to the ground screw (green), the white to either of the silver
terminals, and the black to either of the brass screws on the
other side. Hook the wires clockwise over the screws so they
stay in place as you tighten the screws.
To wire the interior outlet, connect all of the hot wires (black
and any other color except green or white), all the neutral wires
(white), and all of the ground wires (green or bare copper as
shown in Photo 3).
Gently fold the wires into the box, then reattach the outlet
and cover plate. If you damaged the wall around the box, use an
oversize cover plate to hide the problem.
Step 4: Mount and wire the new outlet
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Photo 4: Wire the exterior GFCI outlet
Attach a clamp to the box, feed the cable through it into
the box, then caulk around the clamp. Mount the exterior
outlet box to the house. Wire the outlet and set it in the box.
We used a TayMac weatherproof receptacle kit for our exterior outlet. It came with a standard three-prong
outlet, but since outside outlets must be GFCI protected,
we replaced the kit outlet with a GFCI outlet.
Attach the two mounting lugs to the back of the metal electrical
box, putting them in opposite corners. Fasten a clamp to
the hole in the back of the box, then feed the cable through the
clamp. Apply a heavy bead of silicone caulk around the clamp
and place the box on the wall, inserting the clamp into the hole
in the siding. The caulk makes the hole watertight. We placed
our box horizontally on the lap siding so it could lie flat.
If you have lap siding (wood, hardboard, fiber cement) or
plywood sheathing, mount the junction box to the house, using
exterior-grade fasteners. Simply drive galvanized deck screws
through the mounting lugs. For brick or stucco siding, mount
the box with masonry anchors. For vinyl siding over composition
board, use hollow wall anchors.
Fasten plugs into the openings on both ends of the box. Use
a file to scrape a small notch or “weep hole” in the bottom edge
of the box. This allows any water that gets into the box to drain.
Next, strip insulation off the wire ends. Attach the ground
wire to the green screw in the box and to the green screw on the
GFCI outlet. Make sure to identify the line, hot and white terminals
(they'll be labeled “line,” “hot” and “white.” Attach the
black wire to the brass screw or adjacent push-in hole (labeled
“line”)and the white wire to the silver screw or push-in (Photo
4). Clip the ears off the outlet, fold the wires into the box and
set the outlet in place.
Step 5: Mount the weatherproof box cover
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Photo 5: Mount the box cover
Screw the base to the box. Attach the plastic cover to
the base, sliding it over the hinges until it snaps.
You'll need to remove the middle of the plastic cover base so it'll fit
over the GFCI outlet (don't worry, it's designed to come out by
twisting it with pliers). Set the base on the box, over the outlet.
Make sure the hinges are at the top so the plastic cover will close
over the outlet. Fasten the base to the box with the screws that
came with the kit. Attach the cover to the base (Photo 5). Push the hinge receptacles
sideways over the hinges until they snap in place. Remove
the cord knockouts in the base where the electrical cords will
run. Turn the power on and plug in your miles of holiday lights!
Photo 2: Timer with digital controls
Photo 4: Outlet with built-in timer
Control Lights With a Timer
You don't want to have to step
outside every night, especially in
the middle of a winter deep
freeze, to plug in or unplug your
outlets. That's where timers come
into play. Walk down a home center's
electrical aisle and you'll see
plenty of them. Be sure to buy
one that's rated for outdoor use.
The most common timers plug
into the outlet, then cords plug
into the timer. Most don't need to
be mounted. They just hang from
the outlet. The least expensive
models (about $10) have a dial setting
to run the lights for a specific
period of time, such as two hours,
six hours, or dusk to dawn (see
Photo 1). Slightly more expensive
models have digital controls
for programming (Photo 2).
If you don't want to fuss with
setting the timer, buy a remote
outdoor switch (about $20; not shown).
You can turn the lights off and on
from inside the house, just like
you open and close your garage
door with a remote control from
your vehicle. Look for one
at home centers or search online
for “remote outdoor switch.”
If you need additional outlets in
the yard, install an outlet strip
rated for exterior use (Photo 3).
They plug into your outlet, stake
into the ground and offer multiple
outlets. They're inexpensive at home
centers. You can
only install one strip per
Or buy an outlet with a built-in
timer. Hubbell Electrical Products
makes one that we really like
(about $50; see Photo 4). It has four outlets, GFCI
protection, a built-in junction box
and a rocker switch so you can
put two outlets on the timer and
let the other two run continually
(Photo 4). You can install this unit
as your new exterior outlet, or if
you already have an outlet,
replace it with this. Buy it at electrical
stores or amazon.com.