How to Install Recessed Lights in an Outdoor Block Wall

Select a block in the area where you want to mount a recessed light. Measure the length and height of the block to find the center of the block face. Make a mark on the block halfway between the center and one end of the block. This will allow you to cut through the thinnest part of the block. Not only will this make cutting a hole easier, it will have less of an impact on the strength of the wall.

Insert a masonry bit into the chuck of a hammer drill and tighten the chuck. Set the drill to “hammer” mode. Place the tip of the masonry bit on the mark on the block face. Drill through the face of the block.

Remove the masonry bit from the drill. Insert a concrete hole-saw into the drill, and tighten the chuck. Switch the drill off of hammer mode. Slide the pilot bit into the hole you drilled until the hole saw is flat against the block face.

Cut through the block face with the hole saw. Drill slowly until the saw begins cutting into the block face, then increase speed and rock the hole saw in a counterclockwise motion. Dip the hole saw in a bucket of water every 90 seconds to remove dust and cool the bit. Continue cutting until the hole saw penetrates the block face.

Run a wire from the outdoor light controller to the hole in the block face. If you have access to the top of the wall, you can drop the wire down through the chambers in the blocks to the opening. If the top of the wall is capped, you may have to drill a small hole in the back side of the wall to run the wire to the light. Cut the wire to length with wire strippers.

Connect the wire to the recessed light fixture according to the light manufacturer’s instructions. Most outdoor lights have a terminal with clamps or screws that make connecting the wires easier. Simply lay the wire in the terminal, and clamp or screw it shut to make the electrical connection.

Tuck the wires into the hole in the block face. Push the recessed light fixture into the hole until the retaining ring around its face is flat against the block. Recessed outdoor light fixtures are held in place by friction. The light fixtures range in size from 1 to 6 inches; use a hole saw that is the same size as the body of the fixture, and it will fit snugly in the hole.

Install a trim cap, if one is included with the light fixture. The concrete hole-saw uses a diamond coating to cut and polish the wall at the same time. The edges of the hole will be completely smooth, making the installation look neat, even if the light doesn't have a trim cap.

Connect the other end of the wire to the outdoor lighting controller.