Skylights are wonderful for daylight and mood, and they are also one of the more common places a roof leaks. Any time you cut a hole in a roof and set a window into it, you create a joint that has to be sealed perfectly, and joints are exactly where water gets in. When a skylight leaks, the good news is that it is usually not the glass, and the fix is often more straightforward than people fear.
When water shows up around a skylight, homeowners often assume the unit itself has failed. Much more often, the problem is the flashing, the metal that seals the joint between the skylight and the surrounding roof. Like all flashing, it can lift, corrode, or have been sealed with caulk instead of proper metal, and then water runs into the gap, covered on our page on flashing failures. So a leaking skylight usually needs reflashing, not replacing.
Sometimes the seal or gasket around the skylight itself has aged and cracked, especially on an older unit under years of LA sun. Condensation is another culprit that gets mistaken for a leak, since a skylight is a cold surface where warm, humid indoor air can condense and drip, which ties back to attic ventilation, covered on our page on attic moisture and condensation. And debris damming up around the skylight can back water up under it in heavy rain.
| Cause | What is happening |
|---|---|
| Failed flashing | The seal at the roof joint has lifted |
| Aged skylight seal | The gasket around the unit cracked |
| Condensation | Warm indoor air beading on cold glass |
| Debris damming | Water backs up around the unit |
It is worth telling these apart, since they need different fixes. Water that follows the rain is a leak; moisture that appears in cool weather with no rain, often as beads on the glass, is condensation. If it is condensation, improving attic and room ventilation is the answer, not sealing the roof. Our page on why a roof leaks with no rain covers the distinction.
For a true leak, the fix is usually to reflash the skylight properly, replacing the failed metal and tucking it in correctly rather than adding more caulk over the old failure. If the unit's own seal has aged out, that is addressed, and in some cases an old skylight is worth replacing outright. Our skylight installation and repair handles both, and leak detection confirms the skylight is really the source before anything is opened up.
A skylight leak soaks the framing around the opening every rain, so like any leak it grows if ignored, as our page on delaying a repair shows. If you see a stain spreading from a skylight, a roof inspection pins whether it is the flashing, the seal, or condensation, so the right fix goes in the first time.
Reflashed properly, not just re-caulked. Call (310) 806-5959 or request an estimate below.
Tell us where the water shows and we will trace it and give you a written price, with no obligation.