A skylight floods a room with natural light and can make a dark space feel twice as big. The catch: a skylight is a hole in your roof, so it lives or dies by the installation and flashing.
Types of skylights
- Fixed: sealed, no opening — the most leak-resistant and affordable.
- Vented (operable): opens for fresh air; great for bathrooms and kitchens.
- Tubular: a small reflective tube that brings daylight into hallways and closets.
Why skylights leak (and how to avoid it)
Nearly every leaky skylight comes down to flashing — the metal that channels water around the unit. Done right, with a proper flashing kit and ice-and-water shield, a modern skylight is extremely reliable. Done cheap, it's a recurring headache. Older skylights also have rubber seals that simply wear out after 15–20 years.
Replace skylights with your roof
The single best time to add or replace a skylight is during a roof replacement. The area is already open, the flashing integrates cleanly with the new shingles, and you avoid paying twice for the same work. Re-roofing around an old, failing skylight is false economy — it'll leak and you'll be back up there.
Lightning installs and replaces skylights as part of our roofing work across New Jersey. Ask during your free estimate.
Replace the skylight when you replace the roof
Skylights and roofs age at similar rates, and the flashing kit that seals a skylight is designed to be woven into a new shingle course. Reusing a fifteen-year-old skylight under a new roof means the newest part of the assembly is sealed to the oldest, and the seals and gaskets are the parts that fail. Doing them together costs a fraction of doing them separately.
Deck-mounted versus curb-mounted
- Deck-mounted sits low and looks better from inside and out; it relies on a properly installed manufacturer flashing kit.
- Curb-mounted sits on a built-up frame, which raises it above the roof plane. Better on low pitches and in heavy-snow parts of New Jersey.
Condensation is not always a leak
Water appearing around a skylight in winter is frequently condensation rather than a failure — warm humid indoor air meeting cold glass. The tell is that it appears on cold clear nights rather than during rain. The fix is ventilation and humidity control indoors, not sealant on the roof.
Flashing is the whole job
Almost every skylight leak we are called to is a flashing failure, and most of those are caulk used where step flashing belonged. Sealant is a maintenance item with a service life of a few years; metal flashing lasts as long as the roof. If a quote mentions sealing a skylight rather than flashing it, that is the wrong quote.