Installation of an Additional Wall Dimmer and New Ceiling Light Fixture

Details and Photos About Adding a Dimmer and Ceiling Light Fixture

Dear Mr. Electrician: Is it possible to install an additional dimmer next to an existing one and connect a new ceiling light to the new dimmer?

Answer: Yes. However the methods used to achieve this type of installation will vary according to your building structure and the location of the switches and light fixtures. Below are photos of a simple dimmer and ceiling light installation in a two story condominium.  Text links go to products on Amazon.

An Example of a Light and Additional Dimmer Switch Installed in an Existing Wall

This was the existing dimmer switch for ceiling lights in the adjacent room.
This was the existing dimmer switch for ceiling lights in the adjacent room.

You need to determine where you will be getting power from and where do you want the wall switch to be located.  In the example on this page I was lucky to find power in an existing wall switch where the client wanted the additional switch located.  Not all wall switches have a hot and a neutral.  Some just have a hot and a switch leg which cannot be used to feed something else.

The existing dimmer switch box had the correct wiring (Hot and neutral) in it to facilitate the connection to another light fixture.
The existing dimmer switch box had the correct wiring (Hot and neutral) in it to facilitate the connection to another light fixture. A long thin screwdriver was inserted along side of the switch box to feel for any obstacles such as pipes or wood studs.  A short piece of fish tape can also be used for probing into a wall.

I removed the existing one gang plastic switch box and cut a hole for a new two gang plastic old work switch box.

The existing one gang plastic electrical wall box has been removed and the hole has been made bigger for a new two gang plastic old work electrical box. The existing black switch leg wire was identified with green electrical tape. The other black wires get spliced together.
The old one gang plastic electrical wall box has been removed and the hole has been made bigger for a new two gang plastic old work electrical box.  The existing black switch leg wire was temporarily identified with green electrical tape. The other black wires get spliced together. The wood stud on the left side of this wall opening is perfect for attaching the new two gang plastic old work electrical box for additional support.
The access hole in the wall and the access hole in the ceiling were made using "The Grabowski Method" (Cut at 45 degree angle) to facilitate the installation of a new wire to feed the new light fixture.
The access hole in the wall and the access hole in the ceiling were made using “The Grabowski Method” (Hold the Saw at a 45 degree angle) to facilitate the installation of a new wire to feed the new light fixture. A large hole is needed to fit the Milwaukee right angle drill into the wall to drill up into the top support plate.

I did have to cut holes in the ceiling and the wall to facilitate the installation of a new 14/2 Romex cable to the new light fixture location.  I cut the holes at a 45 degree angle inward to make it easy for patching later.

This hole was made using "The Grabowski Method" of cutting holes in drywall. You simply hold your compass saw at a forty five degree angle when cutting to give you a beveled edge. This makes it much easier to patch the hole using the same piece of cut out drywall and some joint compound.
This hole was made using “The Grabowski Method” of cutting holes in drywall. You simply hold your compass saw at a forty five degree angle inward when cutting to give you a beveled edge. This makes it much easier to patch the hole using the same piece of cut out drywall and some joint compound. Lately I have been using my Milwaukee Cordless Multi-Oscillating Tool to cut such holes.
This hole going up into the ceiling was made with a Milwaukee 0721-20 V28 28-Volt Lithium-Ion 1/2-Inch Cordless Right Angle Drill This view is the inside of the wall through the hole in the previous photo. The big hole in the wall was needed to accommodate the big angle drill and a long auger drill bit.
This hole going up into the ceiling was made with a Milwaukee Right Angle Drill.  This view is the inside of the wall through the hole in the previous photo.  The big hole in the wall was needed to accommodate the big angle drill and a long auger drill bit.

I had to drill a hole using my angle drill to penetrate the top supporting plate in the wall to get the new Romex cable into the ceiling.

The hole for the octagonal electrical box that will support the light fixture. The existing cables in the ceiling are set back far enough to provide clearance for the new box. You can see the side of the laminated beam on the bottom edge of the hole.
You just never know for sure what you find when you make a hole in a ceiling or wall.  This is the hole for the new octagonal electrical box that will support the light fixture where the customer wanted it. The existing cables in the ceiling are set back far enough to provide clearance for the new box. You can see the side of the laminated beam on the bottom edge of the hole.
A view inside of the ceiling. This is the other side of the laminated beam from where the octagonal box is located.
A view inside of the ceiling. This is the other side of the laminated beam from where the octagonal box is located. You can see that there is an existing wire hole from the original installer already drilled.

Because this ceiling was supported by trusses instead of solid wood joists I was able to get my fish tape through very easily after the holes were made.

The fishtapes have been pushed in and are ready for the wire to be attached and pulled in.
The fish tapes have been pushed in and are ready for the wire to be attached and pulled in.

I have several pieces of short fish tape which had broken off of my longer fish tapes.  The short fish tapes come in handy for small jobs like this.

The fish tapes have been pushed in and are ready for the wire to be attached and pulled in.
Two short pieces of fish tape will be used to pull the wire.
The wire is pulled in and ready to have the deep octagon electrical box installed in the ceiling.
The wire is pulled in and ready to have the deep octagon electrical box installed in the ceiling.
This is the view inside of the ceiling with the new wire pulled in through the hole in the laminated beam.
This is the view inside of the ceiling with the new wire pulled in through the hole in the laminated beam.
A 4-Inch diameter by 2-1/8-Inch depth octagonal box was used here to give better leverage support as the box was mounted on the side using #10 x 1-1/2" sheet metal screws and one fender washer where the knock out was. The fender washer allows for a little adjustment to get the box positioned correctly. The other screws lock it in place. Note the copper ground wire attached with a 10/32 screw.
A 4-Inch diameter by 2-1/8-Inch deep metal octagonal box was used here to give better leverage support as the box was mounted on the side using #10 x 1-1/2″ sheet metal screws and one fender washer where the knock out was.  The fender washer allows for a little adjustment to get the box positioned correctly. The other screws lock it in place.  Note the copper ground wire attached with a 10/32 screw.

In most cases I would have used a fan rated ceiling box and installed a 14/3 cable for future fan use.  However this light fixture installation was in a small nook next to the dining room.  It was not likely that a ceiling fan would ever be wanted there.

The light fixture hook and bracket are attached to the deep octagon electrical box in the ceiling.
The light fixture hook and bracket are attached to the deep octagon electrical box in the ceiling.

Everything metal must be grounded.  Because I used a metal box and grounded it, the round fixture mounting bracket is grounded by being physically attached to the ceiling box.  If the ceiling box was plastic it would have been necessary to install a ground wire onto the green screw on the mounting bracket.  The light fixture ground wire will connect to the ground wire in the ceiling electrical box.

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