How to Mount a Light Fixture to an Outside Cinder Block Wall

Place the mounting plate of the new fixture over the junction box, lining up the plate mounting holes with the threaded holes on the junction box. Secure the mounting plate to the junction box with the supplied securing screws and a Phillips screwdriver.

Hold the mounting plate over the junction box and flat against the cinder block wall, if the mounting holes do not line up correctly. Mark the mounting holes onto the wall with a pencil. Remove the mounting plate.

Insert a masonry bit into your drill that is slightly smaller in diameter than the concrete screws you use to mount the plate. Drill a hole at each mark on the wall to a depth of one inch. Hold the mounting plate on the wall, lining up the mounting holes with the holes in the wall. Secure the plate to the wall with 1-inch long concrete screws and a nut driver. Do not over-tighten the screws.

Strip 1/4-inch of insulation from the ends of the wires on the new fixture with wire strippers. Pull the wires out of the junction box and through the mounting plate. Connect the wires according to the light fixture manufacturer's instructions. Twist wire caps over the ends of the wires to join the fixture wires with the house wires.

Push the wires carefully back into the junction box, and align the fixture's mounting holes with the holes on the mounting plate. Secure the fixture to the mounting plate according to the manufacturer's instructions.

Apply a bead of silicone caulk around the outside perimeter of the light fixture where it meets the cinder block wall with a caulk gun. This helps prevent moisture from seeping between the fixture and wall.