Can I Mount an Electrical Box to the Inside of a Block Wall?

Connecting to an Existing Outlet

• Before you connect to an existing ceiling outlet, turn off the main power supply to your home at the breaker panel. By removing the cover from the existing outlet, you can access the outlet wiring. Connect a single-strand, insulated 12-gauge copper wire to the black wire of the existing outlet with a wire nut and another wire to the white wire. Connect a third wire to the ground screw on the side of the outlet. Wrap a different color of electrical tape around the other end of each wire to ensure that you connect the new outlet correctly.

Running a Conduit

• A metal conduit provides protection against wire corrosion, which is particularly useful if you are installing an electrical outlet in a potentially damp area. Use 1/2-inch conduit, which can accommodate all three wires. Run the conduit along the ceiling and down the wall to the location of the new outlet. You can use a conduit bender or preformed elbows to handle any bends.

Installing the New Outlet

• Installing the new outlet is a relatively straightforward process. Place the outlet box below the end of the conduit and mark the screw holes with a pencil. Drill through the marks into the concrete wall with a drill equipped with a masonry bit. Secure the outlet box to the wall with metal screws then connect the ends of the wires with wire nuts.

Considerations

• If you are installing an electrical outlet in a potentially damp area, opt for a ground fault circuit interrupter (GFCI) outlet. This type of outlet helps reduce the risk of electric shock and also helps prevent damage to electrical appliances. If you are not comfortable with electrical wiring or do not have experience installing outlets, contact a licensed electrician to perform this task for you.