Most skylight leaks come from failed flashing around the skylight, not from the glass itself, which is why a bead of caulk almost never fixes the problem for long. A skylight is only as watertight as the metal flashing and roofing details that surround it, and when those wear out, water finds its way in. At Bella Construction & Development Inc., we have been tracking down and fixing skylight leaks for homeowners in Irwin, the Norwin area, and across greater Pittsburgh since 1995, and we can tell you that the lasting fix is almost always about the flashing and the roof, not a tube of sealant.
Why Skylights Leak
A skylight is a hole cut into your roof, and the whole system is designed to keep water out of that hole. When water gets in, it is usually because one of those parts has failed. Here are the most common culprits we find.
- Failed flashing. The metal flashing that wraps the skylight is the number one source of leaks. Over time it corrodes, lifts, or pulls loose, and water sneaks underneath.
- Old or dried out sealant. Caulk and sealant were never meant to be the main defense. They dry out, crack, and shrink, especially through our freeze and thaw winters.
- Worn roofing around the skylight. If the shingles or membrane near the skylight are aging or damaged, water gets in near the opening.
- A failed skylight seal. On older units, the seal between the glass panes can fail, which lets in moisture and shows up as fogging or dripping.
- Condensation. Sometimes what looks like a leak is actually condensation forming on a cold skylight during our big temperature swings. This is common and is often mistaken for a leak.
Figuring out which of these is happening is the whole game. A repair aimed at the wrong cause simply moves the water somewhere else.
Why Caulk Is Not the Answer
When a skylight starts leaking, the tempting first move is to climb up and slather sealant around it. We understand the instinct, but caulk on top of a flashing problem is a short term patch at best. Sealant sits on the surface, and our weather is brutal on surface fixes. The summer sun bakes it, the winter cold shrinks it, and the freeze and thaw cycle cracks it. Within a season or two you are right back where you started, often with more water damage hidden in the roof deck.
Real flashing works differently. It is layered into the roofing so that water is directed over and away from the skylight, using gravity and overlap rather than a sticky seal. When flashing is installed correctly, it keeps water out for decades without depending on caulk to do the heavy lifting.
The Fix That Actually Lasts
A lasting skylight repair starts with a proper diagnosis. We get on the roof, inspect the flashing, check the surrounding roofing, and look at the skylight unit itself. Then we match the fix to the real cause.
If the flashing has failed, the durable solution is to remove the old flashing and install a new flashing kit designed for that skylight, weaving it into the roofing the right way. If the roofing around the skylight is worn, we repair or replace that section so the whole area sheds water as a system. If the skylight unit itself has a failed seal or a cracked frame, replacement is usually the smarter long term move than trying to patch an old unit.
For more on how professional flashing should be installed and maintained, the skylight manufacturer VELUX offers helpful guidance at velux.com. The key point is that flashing is a system, not a smear of sealant, and it should be treated that way.
When to Repair and When to Replace
A repair makes sense when the skylight itself is in good shape and the problem is the flashing or the surrounding roof. If your skylight is relatively new and the glass is clear and solid, reflashing and repairing the roof around it is the right call.
Replacement becomes the better value in a few situations. If your skylight is old and the seal has failed, so you see fogging between the panes, a new energy efficient unit will serve you far better. If you are already replacing the roof, it is the perfect time to replace an aging skylight while everything is open, because you avoid paying twice for the same access. And if the frame is cracked or warped, a new unit is more reliable than a repair.
Helpful Resources on Our Site
- See our full roofing services for homes across Westmoreland County.
- If you are replacing the skylight unit itself, our window services team can help you choose the right one.
- Planning a roof replacement soon? It is the ideal time to address skylights, and we can plan both together.
Why Homeowners Call Bella for Skylights
Skylight leaks are frustrating because they are hard to trace and easy to fix badly. The water often travels along the roof deck before it drips through your ceiling, so the stain inside may be feet away from the real problem. That is why experience matters. We have been solving these puzzles across the Pittsburgh area since 1995, and we know how to find the true source instead of chasing the stain.
We are an Owens Corning Platinum Preferred contractor and a James Hardie Master installer, we hold PA license number 50898, we carry an A plus rating with the BBB, and we have earned 4.7 stars from more than 900 Google reviews. When we fix a skylight, we fix the cause, not just the symptom, so the leak stays gone.
Frequently Asked Questions
Why does my skylight only leak sometimes?
Skylights often leak only during certain conditions, which is a clue to the cause. A leak that shows up during heavy, wind driven rain often points to failed flashing, while dampness that appears during cold snaps may actually be condensation. Wind direction and how the water runs across your roof both play a role. A professional inspection sorts out which one you are dealing with.
Can a skylight leak be fixed without replacing the whole thing?
Often, yes. If the skylight unit itself is sound and the problem is the flashing or the roofing around it, we can repair those without replacing the skylight. Replacement is only necessary when the unit’s seal or frame has failed. We always recommend the least invasive fix that will actually last.
How long should a skylight last?
A quality skylight typically lasts 20 to 30 years, though the flashing and seals may need attention sooner depending on your roof and our weather. Fogging between the panes is a sign the seal has failed and the unit is near the end of its life. Regular inspection helps you catch small problems before they become leaks.
Should I replace my skylight when I get a new roof?
If your skylight is more than about 15 years old, replacing it during a roof project is usually the smart move. The roof is already open, so you avoid paying for the same access twice, and you start fresh with a matched, watertight system. We are happy to price both options during your inspection.
Stop the Leak for Good
If your skylight is dripping, staining the ceiling, or fogging up, do not settle for another round of caulk. Bella Construction & Development Inc. will find the real cause and fix it the right way. Call us at 724.515.5163 for a free inspection, or visit us at 10561 Center Hwy, Irwin, PA 15642. We will get you dry and keep you that way.
Last updated August 2026.