Flashing is the key to a skylight that won't leak water into the roof
Cutting a hole in a perfectly water-tight roof is asking for trouble, and true to form, skylights are notorious for leaking. So notorious that a major manufacturer, Velux, developed flashing kits that could be shipped with the skylight to eliminate origami-gone-wrong on the roof.
As a remodeler, you will inevitably wind up replacing a skylight or fixing a leaky one, as Integrity Roofing demonstrates in this video. The skylight had been leaking for a while, and as they open up the assembly, they find rusty roofing nails, which is evidence that the leak was in the roofing and flashing around the skylight, not the skylight itself.
Flashing a curbed skylight is a relatively simple process, but the details are critical—because it is a hole in the roof.
Step by step:
- Remove shingles around the skylight from the top down. Use a pry bar to break the seal between the shingles above, and then loosen the nails and pull them.
- Remove the skylight so that you can inspect, repair, or replace the curb.
- Remove and replace the curb as needed.
- Install peel and stick membrane to the bottom, sides, and top — in that order.
- Install metal flashing in the same order: bottom, sides, top.