Installing Basic Two-Bulb Outdoor Flood Light.

Electrical Improvements:

Installing Outdoor Flood Lights
Under The Eaves

In This Article:
Related Articles:
Skill Level: 2-3 (Basic to Intermediate) Time Taken: A Couple Of Hours

By , Editor


Warning: Electrical work can be dangerous. Be sure to read Cautions and Warnings at the end of this article.

My backyard was kinda dark at night, so I decided to install some sort of flood light beneath the eaves at the back of my house. Rear view of house, location of outdoor flood light.


Plywood soffit alternating with vented soffit. I figured that I would mount the light fixture near the end of the unvented soffit.

Note that this house, built in 1963, has soffits made from particleboard.


I figured out the best location for the light fixture and marked the centerline of the hole for the wire. Wood soffit or eaves, possible spot to mount light fixture.


Drilling large hole in wood soffit with cordless drill. I drilled a 1 inch hole in the soffit.

Why such a big hole? I need a big hole to fit the cable clamp that will be screwed into the back of the junction box.

If a big drill bit isn't available, two or more smaller holes could be drilled, and then the wood cut out with a keyhole saw, a file or a rasp.


Running The New Wire:

I fed about 2 feet of 14-2G wire into the hole.

Then I used a spring clamp to hold the wire to the ladder, so it wouldn't fall out of the hole while I went upstairs.

Feeding wire into a hole in the soffit.


End of wire where it entered the attic, fed from below eaves outside. Upstairs in the attic I found the end of the new wire.

That white wire that goes across the top of the picture is for another light fixture on the side of the house.


I pulled the wire across the rafters and ran it into the existing junction box that had been installed a couple of years ago.

The blue arrow indicates the new wire after it had been secured in the j-box.

Of course, I TURNED OFF THE POWER to this circuit.

New 14-2G cable sticking out of existing junction box in attic.


New wire fastened to underside of rafters. Then I worked back towards the other end of the wire, driving staples into the rafters to secure the cable to the underside of the rafters.


Then I made the connections at the j-box. Wiring connections at junction box.

When this junction box was installed, we ran 14-3G wire from a two-gang switch box near the back door. The black wire controls two pairs of flood lights on the side of the house. The red wire was intended to power this flood light at the back of the house.

So I connected the neutral (white) wire to the existing group of white wires. The black wire in my new cable was connected to the existing red wire. The other end of the red wire will be connected to a new switch.


Preparing The Outdoor Junction Box:

These are the components of a basic two-head flood light:

The junction box.

The bulb holders and mounting plate. 

Parts for outdoor light: J-box, bulb holders, base plate.


Installing plastic plugs in outdoor junction box. I applied some thread compound to the plastic plugs and screwed them into the threaded holes I wouldn't be using.

Some outdoor j-boxes come with a small tube of thread sealant. This box did not, so I just used TFE pipe thread compound. Just make sure the compound is safe for use on PVC.

This is a 3/8" cable clamp, which is commonly used in circuit breaker panels and metal junction boxes to prevent the wire from being pulled out. Cable clamp used to prevent wire from being pulled out of junction box.


Cable clamp mounted in back of outdoor junction box. I installed the cable clamp in the back hole in the j-box.


Mounting The Junction Box:

I slipped the end of the cable through the clamp, and tightened the two screws. Securing electrical cable in j-box by tightening clamp screws.


Attaching outdoor junction box to underside of eaves. While making sure the cable clamp went into the 1 inch hole, I mounted the junction box to the soffit. To prevent corrosion, I used #8 stainless steel sheet metal screws.


Note the amount of wire sticking out of the j-box... it's about 8 inches. Electrical rough-in: Wire hanging from junction box.


Wiring a junction box: ends of wire stripped. I removed the cable sheath and stripped about 1/2" of insulation from the black and white conductors.


Note the ground wire. I just wrapped the bare wire around the ground screw and tightened it. I left some excess bare wire, just in case it's needed in the future. I tucked this extra ground wire into the junction box. Bare ground wire secured under green ground screw.


Got Vinyl Or Aluminum Soffit?

What if the soffit is not plywood or particle board? Many houses today have vinyl or aluminum soffit, making it difficult to attach a junction box. Vinyl or aluminum soffit usually just hangs between a channel on the wall and the fascia. One mounting ear on the box can easily be attached to the tail end of a rafter or truss, but the other ear will probably not have any wood structure behind it. Maybe both ears could be screwed to the truss tail, but that limits the ways the box can be oriented. Besides, the soffit could get crushed when the screws are driven tight. It might be possible to support the box from aluminum soffit, but certainly not from vinyl soffit, which would probably sag under the weight of the light fixture.

Method of mounting outdoor junction box to outside wall just below roof overhang.

One Solution:

It's possible to mount the box on the wall just below soffit... IF there is wood sheathing behind the siding. (Some houses use rigid foam over the studs with no wood sheathing. Argh!)

This method would require a short piece of 1/2" PVC conduit and a male threaded adapter to protect the cable between the box and the hole in the soffit.

Ideally the screws securing the box would not crush the vinyl siding. Putting a stack of washers (stainless steel is best) under the mounting ears can create a "standoff" that holds the box away from the sheathing, yet keeps the j-box from rocking too much. Plastic shims would work too.

Of course, I'm just showing a mock-up on the back of my garden shed. An actual installation would require a hole in the soffit, and the conduit would need to extend above the soffit for an inch or two.

Half-inch PVC conduit requires a 7/8" to 1" diameter hole. Drilling that size of hole in vinyl soffit could be done (carefully) with a spade bit.

Drilling in aluminum soffit might not be so easy. That might require a small starter hole with a regular twist-drill, and then making the hole bigger by cutting with tin snips or diagonal cutters (wire cutters).


Preparing The Light Fixture:

Applying thread sealant to bulb holder for outdoor light fixture. I applied some thread sealant to the threads of each bulb holder.


Then I screwed the bulb holders into the base plate. I did not tighten the locking ring because I'll need to adjust the angle of the bulbs later. Assembling outdoor flood light fixture.


Outdoor light fixture after wires are connected. I connected all the white wires together with a "wire nut", and then all the black wires.

Note that I placed the black foam gasket over the base plate. (I forgot this at first and had to back-track.)


I tucked all the wires carefully inside the junction box and pushed the base plate up towards the j-box. Tucking the wires inside the j-box.


Fastening the light fixture to the junction box. I attached the base plate with the two mounting screws provided.


Then I installed two fluorescent exterior-rated flood lights.

These were 26 watt fluorescent bulbs that are supposed to be as bright as 90 watt conventional incandescent bulbs.

Installing compact fluorescent lights (CFL) in outdoor light fixture.


Wiring a switch for outdoor lights. I also connected a switch in the j-box that I had installed a couple of years ago.


Adjusting The Angle Of The Floodlights:

I used a short screwdriver to loosen the screw at the elbow. Then I could bend the elbow to the desired position. Adjusting angle of flood lights by loosening screw on bulb holder elbow.


Adjusting flood light by turning bulb holder in mounting plate. To rotate the bulb holder, I loosened the locking ring with a pair of Channel-Lock pliers.


Then I restored the power.

The final result: Lights in the back yard. Now I don't have to stumble around in the dark.

Outdoor flood lights after completion.


Don't Point That Thing At Me:

I have seen dozens of houses with flood lights that are aimed almost straight outwards, like a pair of car headlights. This may seem logical to some homeowners, but I think this practice is stupid and rude.

Think about it... you're walking along a dark road and a car approaches with their high-beams on. You can't see a darned thing... indeed you can be momentarily blinded. The driver can see you just fine, but all you can see is a bright light. Police use this technique at night... they shine a bright flashlight into the eyes of a suspect or motorist. That person can't see a thing, and they are put at a disadvantage.

Are you going to treat your guests that way? Your wife and children? Do you want to look into a bright light when you walk towards your house? Maybe some people aim their lights sideways to illuminate the farthest parts of their yard, in which case they are just plain cheap. The proper way to aim a flood light is down, with a slight angle sideways so you aren't wasting energy illuminating the side of your house. If you want to light up every corner of your yard then install more lights, aimed downward of course.

If you live in a neighborhood where the houses are close together (like I do) you might run afoul of local laws if you point your floodlights at your neighbors property or the public street. Whatever the rules are, it's just inconsiderate to aim flood lights sideways, and it certainly makes a home feel less comfortable.



Cautions and Warnings:

  • Turn off the power before working on electrical systems.

  • If you are uncertain about the techniques shown here, then the best approach is to hire an electrician.

  • A permit may be required for electrical changes. Contact your local Building Department.

  • The methods shown in this article may not meet electrical codes in your area. Contact you local Building Department to find out which methods are legal for your area.

  • We strive to show methods that are accurate and comply with applicable electrical codes. However, we cannot guarantee that methods shown on this site will always be correct, or correct for your local building codes.

  • Do not rely on this article, or this web site, for ALL of your electrical information. We recommend reading one of the many books available at bookstores, home stores, or your local library. Research this topic fully before attempting any electrical project.

  • If you follow the procedures shown here, you do so at your own risk.

  • This article (and any other pages on should not be considered as "instructions". and it's publisher will not be held liable for any harm or damage caused by following the information shown here. This article is for entertainment purposes only.



More Info:

Tools Used:
  • Cordless Drill/Driver
  • Cordless Impact Driver (Optional)
  • Wire Cutters
  • Wire Stripping Tool
  • Screwdrivers
  • Channel-Lock™ Pliers
Materials Used:
  • Round Outdoor Junction Box
  • 3/8" Cable Clamp
  • Two-Head Floodlight
  • Compact Fluorescent Flood Lights
  • 14-2G Cable
  • Cable Staples
  • Pipe Thread Compound
  • Sheet Metal Screws, #8 x 1", Stainless Steel
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Written August 28, 2008