How to Install a Sun Tube on a Metal Roof

Go into the attic above the room where you are planning to install the sun tube. Clear any insulation away from the joists and ceilings in the area. Drill a small hole through the ceiling at the midpoint between two ceiling joists.

Go into the room below where you drilled the hole and confirm that the location is right. Cut the appropriately sized hole for the size of sun tube you are installing through the ceiling with a utility knife or drywall saw, using the small hole that you drilled as a center point.

Determine the right location in the roof for the sun tube by going back into the attic and looking at the layout. Read the instructions for the sun tube carefully; there are different styles of sun tube and they have different requirements for installation in a roof. For most sun tubes, you will either extend the hole that you cut in the ceiling straight up to the roof or you will run the pipe the shortest distance from the hole to the roof, which may be at a 45 degree angle.

Drill a hole through the roof in the center of the location that you determine is the best for the sun tube, using a long bit that will drill through both wood and metal. Avoid cutting through rafters by centering the hole between two rafters.

Go onto the roof and cut the required size hole in the roof using a saber saw fitted with a metal cutting bit.

Install the riser for the sun tube over the hole in the metal roof. The riser converts the slope of the roof to a flat surface that the sun tube dome will sit on.

Install flashing on the uphill side of the riser by fitting it underneath the edge of the metal roofing that you cut away then running it up the side of the riser to prevent leaking. Cover any metal joints with roofing tar.

Fit the reflective tube to the underside of the sun tube dome from inside the attic and extend it through the hole in the ceiling.

Fit the diffuser onto the end of the reflecting tube and affix it to the ceiling with screws and a screwdriver.