Install a Skylight 10 - Building the Light Shaft

The light shaft directs light from the skylight on the roof to the interior of your home. The following pages describe how to frame, insulate, and finish a light shaft.

Framing the Light Shaft

The frame for the light shaft not only provides a nailing surface for the walls, but also joins the ceiling to the roof, giving support to both.

Measure the distance between the ceiling headers and the roof headers at every corner, and at least every 16 inches in between. Cut the vertical studs to the measured lengths.

Unless your roof is flat and your light shaft straight, you'll need to cut one or both ends of the studs at an angle.

If you want lights in the shaft, position the studs to clear any electrical outlet or recessed light fixtures you plan to install.

Toenail the studs to the ceiling and roof headers with 8-penny nails. Make sure you install two studs at each corner to provide nailing for the wallboard or other material used to finish the shaft.

Insulating the Light Shaft

For better energy efficiency plan on insulating the light shaft. If your attic is not insulated, you may want to insulate it at the same time. Be sure to install any electrical wiring before you insulate.

Caution: Remember to wear gloves, a long-sleeved shirt, long pants, a painter's mask, and goggles when working with insulation.

Rolled insulation works best for the short, uneven lengths needed in a light shaft.

Buy 6-inch-thick insulation in the width that will best fit between the studs.

Measure a length of insulation to fit in each stud opening, and cut the insulation with a utility knife guided by a straightedge. Place the insulation between the studs with the vapor-barrier side toward the shaft opening; staple the edge flaps to the studs.

Finishing the Light Shaft

How you finish the light shaft is limited only by your imagination. Here are some ideas to get you started. Wallboard that is painted white or a light color is one of the best finishes for reflecting light. Finishing with wallboard and paint is economical, but takes time and skill for good results.

If your walls are paneled, you may want to finish the light shaft to match.