How to Install Recessed Lighting on Sloped Ceilings

Before you begin the installation process, you’ll need to determine the slope of your ceiling. Be sure to use a ladder tall enough to safely reach the highest area of the sloped ceiling.

• Calculate the height difference, in feet, between the shortest wall and the highest point of your ceiling. This is called the rise.
• To calculate the rise, measure the height of the shortest wall. Then measure the height of the highest point of the ceiling and subtract the two. The difference is the ceiling’s rise.
• Next, measure the total length, in feet, from the shortest wall to the highest point on the ceiling. Take this measurement parallel to the floor. This is called the run.
• Determine the slope by using an online slope calculator or the following formula:

Rise / Run = slope (or tangent)

Convert the tangent to angle by using the tan-1 function on a scientific calculator

Example: 6-ft rise / 12-ft run = .5 tangent

.5 (tan-1 ) = 26.6 degrees

• Use the slope to help you decide which sloped ceiling recessed lighting kits your ceiling can accommodate. The slope range is specified on the box detailing how to replace a recessed light with a statement such as “For use in 2/12 to 6/12 pitch slopes”. Adjustments can be made for the slope you need within the house. Follow the manufacturer’s instructions to fine-tune the specific slope of your ceiling.

There are two options for performing this task. To begin, use a stud finder to make sure the holes do not overlap a joist. Then choose one of the two options below.

There are a number of ways to lay out recessed light fixture locations. If you have a laser level equipped with a plumb dot, you can mark light locations on the floor with blue tape and a pencil, and then plumb up from there to mark the ceiling. You can also use a reference line to pull measurements up from where the ceiling intersects the lower wall, or down from the highest point of the ceiling. You’ll also want to pull across from a side wall. Make sure you use the same reference line for your measurements to keep layout consistent. 

Option A:

• If a template is included with your sloped recessed lighting installation kit, use it to draw a circle on the ceiling using the center point of the desired light location as a guide.
• Cut the hole with a drywall saw and mark all the light locations.
• Use careful, shallow strokes with the drywall saw. Make sure not to snag any wires that may be in the ceiling cavity.

Option B:

• Cut the hole freehand using a drill with a hole-cutting attachment and mark all light locations. Make sure that the hole saw diameter matches the dimensions of the light fixture you’re using. The manufacturer’s instructions will specify this diameter.
• Run the drill at a slow speed to get it started and use control when nearing the end of the cut so the hole saw doesn’t plunge deep into the cavity. Make sure you do not snag any wires that may be in the ceiling cavity.

Tip: Use a hole saw dust catcher to contain dust as you’re cutting. 

Now that the holes are created, you can proceed to the next step of the remodeling recessed lighting task.

• Run the cable wire from the power source to a switch box, and then through the first hole.
• Make sure to leave at least 16 extra inches of cable to make the wiring process easier.
• To route wire through the top plate of the wall or through ceiling joists, use a power drill with a longer drill bit to avoid cutting additional access holes in the ceiling.
• Open the light’s junction box and run the cable through it.
• Clamp it and strip insulation to make wire splices: connect white to white, black to black and ground to ground.
• Fold the wires into the box and place the cover.

Recessed or “old work” lighting fixtures have four clips that easily clamp the recessed lighting housing to the ceiling by pushing down on top of the drywall. 

• Pull the clips inward so they do not stick outside the housing.
• Slip the housing into the hole and push the body up until it’s flush with the ceiling.
• Lightly push each clip up and outward until it connects and clamps the light fixture.

Most recessed lighting trims are mounted with squeezable rod springs or coil springs.

Tip: Wear disposable latex gloves when replacing recessed lighting trim to keep the trim and ceiling clean during installation. 

For coil springs

• Hook each spring to its assigned hole inside the housing can.
• Pull out each spring and connect it to the trim.
• Carefully guide the trim into position.

For rod springs

• Press and insert both ends of each spring into their assigned openings.
• Push the trim into position.

Changing a recessed light bulb can often be done without removing the trim. If you do need to remove the trim or are considering replacing recessed lighting with a different trim design, repeat the steps outlined here.