A skylight inspection means checking four things: the ceiling below it for water stains, the seals and flashing around the frame for cracks or gaps, the glass for fog or chips, and the ventilation mechanism if it’s an operable unit. Catching a problem in any of these early — before the next storm — is usually the difference between a $200 reseal and a $2,000+ replacement.
Skylights take more weather exposure than any other part of a roof, and Westchester’s mix of heavy winter snow, spring freeze-thaw cycles, and summer storms puts real stress on the seals and flashing every year. Here’s what to check, what each sign actually means, and when it’s time to call a professional rather than climb up yourself.
Check the Ceiling and Walls Below First
This is the easiest check and the one most homeowners skip because it doesn’t require a ladder. Water finds the path of least resistance, so a leak often shows up several feet from where it actually enters — walk the ceiling and upper walls around the skylight looking for:
- Water stains or yellowish discoloration
- Peeling or bubbling paint
- Soft or spongy drywall
- Mold, mildew, or a musty smell
Any of these means water has already gotten past the seal at some point, even if it isn’t actively dripping right now. It’s worth checking after the season’s first hard rain or after snow melt, since that’s when marginal seals tend to show themselves.
Inspect the Seals and Flashing
Flashing is the metal detail where the skylight meets the roof, and it’s the single most common failure point — more skylight leaks originate at the flashing than at the glass itself. From inside, if the skylight opens, check the rubber gasket around the frame for cracking or visible gaps. From the ground or a window, look at the flashing for rust, gaps, or lifted edges where it meets the shingles.
Safety note: don’t get on the roof yourself to inspect flashing closely, especially on a steep pitch or after rain, snow, or ice. This is exactly the kind of check a professional does safely with the right equipment — and if a DIY inspection turns into an amateur repair with nails through the flashing, that’s a common cause of leaks that weren’t there before.
Assess the Glass and Frame
Cracks or chips in the glass are obvious once you’re looking for them, but fogging or haze between the panes is a subtler and equally important sign — it means the insulated seal inside a double-pane unit has failed, letting moisture in between the layers. That’s not something caulk fixes; it usually means the glass unit needs replacing.
For the frame itself: wood frames can develop rot or warping where they’ve held moisture, while metal or composite frames may show corrosion at the joints. Either shortens the skylight’s remaining life and is worth flagging to a contractor even if there’s no active leak yet.
Test Ventilation on Operable Skylights
If your skylight opens, the ventilation mechanism needs to move freely and the weep holes — the small drainage holes along the lower edge of the frame — need to be clear of debris. Blocked weep holes trap condensation, which fogs the glass and can look identical to an active leak from the outside, even though the real fix is just clearing the drainage path rather than resealing anything.
Condensation on the inside of the glass on cold mornings is often normal humidity, not a leak — but if it’s forming as pooling water rather than a light film, or if it’s showing up even on dry days, that points to a ventilation or seal problem worth having checked.
When It’s a Repair vs. When It’s a Replacement
| Usually a repair | Usually a replacement | |
|---|---|---|
| Seal/gasket | Cracked but glass is clear | Fogging between panes (failed insulated seal) |
| Flashing | Rusted or gapped, glass intact | Repeated flashing failures on the same unit |
| Glass | Minor surface haze, no cracks | Cracked, chipped, or structurally compromised |
| Age | Under 10–12 years old | Past 15 years, especially with any of the above |
A skylight that’s had two or more repairs in the past few years is usually a better candidate for replacement — the repeated labor cost starts to approach what a new unit would have cost, on a skylight that’s still going to fail again.
What Skylight Repair and Replacement Cost
- Minor repairs (resealing, weep hole clearing): roughly $75–$250
- Flashing repair: typically $150–$500
- Leak repair with some water damage: usually $225–$800
- Full skylight replacement: generally $2,000–$5,000, depending on size, type (fixed vs. vented), and roof access
Costs climb with roof pitch and height — a second-story skylight on a steep roof takes longer and needs more safety setup than a single-story, low-pitch unit.
How Often to Inspect
A visual check from the ground or inside takes a few minutes and is worth doing seasonally — after the first hard freeze of winter and again in spring once snow has melted. A professional inspection is worth scheduling every year or two, or any time you notice a stain, drip, or fogging, since a trained eye catches flashing and seal issues that aren’t visible from inside the house.
EXPERT INPUT OPPORTUNITY: A line here on a skylight inspection or repair American Star has actually done in Westchester — what the issue turned out to be (flashing vs. seal vs. glass) and how it was fixed — would carry more weight than the general guidance above.
Frequently Asked Questions
How do I know if my skylight is leaking or just has condensation? Condensation is usually a light film on the inside of the glass, most common on cold mornings, and it clears as the room warms up. An active leak shows up as dripping, pooling water, or a spreading ceiling stain that doesn’t go away on its own — if you’re unsure, a paper towel test (dab the moisture; condensation is just water, a leak often carries dirt or debris) can help, but a professional inspection settles it for good.
Can I inspect my skylight myself, or do I need a professional? The ceiling, frame, and glass can be checked safely from inside your home. The flashing and roof-level seals should be left to a professional — that part of the inspection requires being on the roof safely, and it’s also the area most prone to leaks if handled incorrectly.
How long do skylights typically last? Most residential skylights last 10–20 years depending on the material and installation quality, with the seals and flashing usually failing before the glass or frame itself does.
Is a foggy skylight a safety issue? Not a safety issue on its own, but it means the insulated glass seal has failed and moisture is trapped between the panes — the unit is losing energy efficiency and will typically need the glass or the whole unit replaced.
Skylights bring in natural light, but they’re also one of the more exposed points on any roof — a small seal or flashing issue that goes unnoticed can turn into a much larger repair by the next storm season. If you’ve spotted any of the signs above, or it’s simply been a while since your skylights were professionally checked, American Star Contractor offers skylight inspection and maintenance services across Westchester County. Call (800) 663-6036 for a free quote.